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Abstract

Degenerative mitral valve disease (DMVD) is the most common cardiac disease in dogs. Although the disease is frequently described in the veterinary literature, many aspects are still unknown or controversial. Based on recent research findings, this article addresses the etiology, pathogenesis, inheritance, diagnosis of early DMVD, diagnosis of mild decompensated heart failure, and efficacy of early medical intervention in clinically compensated dogs.

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... Mitral regurgitation due to myxomatous mitral valve diseases had been reported to account for 75 per cent of the cases of decompensated heart failure in dogs (Hansson et al., 2002;Häggström et al., 2004 andSmith et al., 2005). ...
... Congestive heart failure (CHF) was reported as one among the most frequently encountered cardiac diagnoses, with an estimated prevalence of one per cent (Fisher et al., 2001). Häggström et al. (2004) documented that heart failure had been accounted for 7.3 per cent of mortality in dogs in an age of below 10 yrs. and the particular condition was listed as the third most common cause of death in dogs of that age group. ...
... The incidence of valve involvement in dog was reported as follows: 62 per cent incidence of mitral valve alone, 32.5 per cent incidence of mitral and tricuspid valves and 1.3 per cent incidence of tricuspid valve alone (Buchanan, 1977). The pulmonary and aortic valves are less commonly affected (Häggström et al., 2004). Vollmar (1999 and ...
Thesis
Acquired heart diseases (AHD) are common and often fatal when it leads to CHF in dogs and it occurs most often secondary to degenerative mitral valve disease (MVD), dilated cardiomyopathy (DCM), pericardial diseases and Hypertrophic cardiomyopathy (HCM). Early recognition of AHD is of clinical importance. Tissue Doppler echocardiography is an ideal tool to evaluate patients with acquired heart diseases, offering the potential to improve early identification and management of AHDS. The objectives of this study were to quantify the global and regional myocardial function by Tissue Doppler echocardiography in acquired heart diseases of dogs; to compare the diagnostic efficacy of different modes of Tissue Doppler echocardiography in dogs; and to establish the usefulness of biochemical marker in diagnosis of acquired heart diseases in dogs. 106 animals with acquired heart diseases were selected based on echocardiographic findings from the animals that were brought to MVC teaching hospital and they were grouped as apparently healthy dogs, DCM, MVD, Pericardial diseases and HCM groups. Parameters of the study included Prevalence analysis, Medical history, Clinical presentation, Baseline Haematology panel, Baseline serum biochemistry panel, Radiography, Doppler BP, ECG, Echocardiographic indices such as 2-D echocardiographic indices, M-Mode Echocardiographic indices and Colour flow Doppler, Tissue Doppler Imaging and NT-proBNP Assay. The incidence of AHDs was found to be 0.37 per cent in the five semester study period. Labradors and Spitz were found to be commonly affected with DCM and MVD respectively. Older male dogs were found to be more commonly affected. The observed chief complaints included inappetance, exercise intolerance, abdominal enlargement, syncope and weakness. Tachycardia, ascites and murmurs were the common clinical signs in all the groups of AHDs. Haematological assessment showed no significant changes. Serum biochemical assessment showed significant hypernatremia in all groups except HCM. Radiographic signs of AHDs included cardiomegaly, pulmonary oedema and left atrial enlargement. Dogs with DCM and pericardial effusion had significantly elevated VHS and confirmed the presence of acquired heart disease. ECG findings in AHDs were the DCM dogs had characteristic arrhythmic pattern of atrial fibrillation in 20.69 per cent cases and atrial flutter in 8.62 per cent of cases. MVD group dogs had atrial enlargement in 51.28 per cent; pericardial effusion group had low voltage QRS complex and electrical alternans in 83.33 per cent; and HCM group had ventricular enlargement in 100.00 per cent cases. Echocardiographic findings in DCM were LV dilatation, LA dilatation, increased LA/Ao ratio, decreased LVFW and septal thickness, decreased FS, increased LVIDd & LVIDs, increased EPSS and secondary regurgitation of mitral valve and Tricuspid valve; and in MVD were LA dilatation, increased LA/Ao ratio, FS<60 per cent with cardiac failure were identified and mild, moderate and severe MR was found in colour flow Doppler; in pericardial effusion were echo-free space around ventricular chambers, Right Atrial collapse indicating tamponade; and in HCM were LV hypertrophy, SAM and increased FS were observed. In pulsed wave tissue Doppler highly significant decrease in Sm and Em/Am ratio all groups; and significant decrease in Em in all groups were observed; and significant increase in Am in pericardial effusion and HCM were observed. Very typical Em/Am ratio reversal (Em/AM<1) was observed in pericardial effusion and HCM group. In NT-proBNP assay a highly significant increase in levels was observed in DCM, MVD with systolic failure, MVD without systolic failure and in occult cardiac diseases which indicated that this marker is highly sensitive and specific for cardiac diseases. Post-mortem examination of DCM dogs reveals the heart was enlarged, globular, and flabby in appearance with rounded apex due to generalized ventricular dilatation on gross pathology and on transverse biventricular slice of heart the marked dilatation of lumen, attenuation of papillary muscles and thinning of free walls of ventricles were observed. On histopathology left ventricular myocardium showed attenuated wavy fibre type of change. In this study the following conclusions made were Tissue Doppler Echocardiography of acquired heart diseases the regional and global velocities were highly significantly decreased in dogs; Pulsed wave Tissue Doppler Echocardiography is very effective in assessing the peak myocardial velocities in real time, when compare to 2D Tissue Doppler Echocardiography and Colour M-mode Tissue Doppler Echocardiography in dogs and the cardiac biomarker NT-proBNP was very effective and specific marker and very useful in diagnosing and categorizing the cardiac diseases in dogs.
... Recall from Chapter 40, Section 40.4.3.1 and Chapter 43, Section 43.7.1 that degenerative mitral valve disease (DMVD) is common in adult dogs, especially in small breeds [4,[29][30][31][32][33][34][35]. ...
... Affected dogs develop morphological changes in the mitral valve, including valve thickening, bulging, and eventual prolapse [33,[36][37][38]. This results in MR [33]. ...
... Affected dogs develop morphological changes in the mitral valve, including valve thickening, bulging, and eventual prolapse [33,[36][37][38]. This results in MR [33]. When MR is mild, cardiac function is relatively unchanged [33]. ...
Chapter
The normal heart sounds, S1 and S2, create the characteristic “lub‐dub” that is heard on cardiothoracic auscultation. Additional heart sounds, S3 and S4, are not appreciated in the normal patient. When S3 or S4 is present in addition to S1 and S2, the patient is said to have a gallop rhythm. If both S3 and S4 are present in addition to S1 and S2, the patient has a summation gallop. Gallops are associated with a decrease in ventricular compliance. When it occurs, S3 rides on the coattails of S2 and represents the rapid filling of the ventricles with blood during early diastole. By contrast, S4 precedes S1 and represents atrial contraction. Both S3 and S4 are pathologic‚ and a patient that presents with either clinical finding should be evaluated for underlying cardiomyopathy and/or systemic disease. Common causes of S3 include congestive heart failure (CHF) secondary to dilated cardiomyopathy (DCM), patent ductus arteriosus (PDA), and severe mitral regurgitation (MR). Common causes of S4 include hypertrophic cardiomyopathy (HCM) and systemic hypertension. Hypertension may be primary or secondary. Renal disease and hyperthyroidism are commonly implicated in cases involving secondary hypertension.
... CHF was staged according to the MMVD was diagnosed by trans-thoracic echocardiography (CarisPlus ® , color Doppler, Italy), based on the combination of following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve lea ets by 2-D echocardiography on right parasternal long-axis (RPLA) and apical 4-chamber views, and identi cation of mitral valve regurgitation on left apical 4-chamber view by color Doppler examination. Mitral regurgitation was also con rmed by color M-mode examination at right parasternal short axis view -mitral valve level (73,74). ...
... The dogs with score >4 were forwarded to echocardiographic examination for nal diagnosis. Radiographic and clinical ndings were interpreted in a combination with the echocardiography, providing a nal diagnosis of acute CHF due to MMVD (73)(74)(75). ...
Preprint
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Background: Platelets play a central role in the development of cardiovascular diseases and changes in their proteins are involved in the pathophysiology of heart diseases in humans. There is lack of knowledge about the possible role of platelets in congestive heart failure (CHF) in dogs. Thus, this study aimed to investigate the changes in global platelet proteomes in dogs with CHF, to clarify the possible role of platelets in the physiopathology of this disease. Healthy-dogs (n=10) and dogs with acute CHF due to myxomatous mitral valve disease (MMVD, n=10) were used. Acute CHF was defined based on the clinical (increased respiratory rate or difficulty breathing) and radiographic findings of pulmonary edema. Dogs Blood samples were collected into tubes with acid-citrate-dextrose, and platelet-pellets were obtained by centrifuge and washing steps. Platelet-proteomes were identified using LC-MS based label-free differential proteome expression analysis method and matched according to protein database for Canis lupus familiaris. Results: Totally 107 different proteins were identified in the platelets of the dogs being 4 out of them were significantly up-regulated and 6 down-regulated in acute CHF dogs. Guanine-nucleotide-binding protein, apolipoproteins (A-II and C-III) and clusterin levels increased, but CXC-motif-chemokine-10, cytochrome-C-oxidase-subunit-2, cathepsin-D, serine/threonine-protein-phosphatase-PP1-gamma-catalytic-subunit, creatine-kinase-B-type and myotrophin levels decreased in acute CHF dogs. These proteins are associated with several molecular functions, biological processes, signaling systems and immune-inflammatory responses. Conclusion: This study describes by first time the changes in the protein composition in platelets of dogs with acute CHF due to MMVD. Our findings provide a resource for increase the knowledge about the proteome of canine platelets and their roles in CHF caused by MMVD and could be a tool for further investigations about the prevention and treatment of this disease.
... MMVD was diagnosed by trans-thoracic echocardiography (CarisPlus ® , color Doppler, Italy), based on the combination of following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve lea ets by 2-D echocardiography on right parasternal long-axis (RPLA) and apical 4-chamber views, and identi cation of mitral valve regurgitation on left apical 4-chamber view by color Doppler examination. Mitral regurgitation was also con rmed by color M-mode examination at right parasternal short axis view -mitral valve level (66,67). ...
... The dogs with score >4 were forwarded to echocardiographic examination for nal diagnosis. Radiographic and clinical ndings were interpreted in a combination with the echocardiography, providing a nal diagnosis of acute CHF due to MMVD (66)(67)(68). ...
Preprint
Full-text available
Background: Platelets play a central role in the development of cardiovascular diseases and changes in their proteins are involved in the pathophysiology of heart diseases in humans. There is lack of knowledge about the possible role of platelets in congestive heart failure (CHF) in dogs. Thus, this study aimed to investigate the changes in global platelet proteomes in dogs with CHF, to clarify the possible role of platelets in the physiopathology of this disease. Healthy-dogs (n=10) and dogs with acute CHF due to myxomatous mitral valve disease (MMVD, n=10) were used. Acute CHF was defined based on the clinical (increased respiratory rate or difficulty breathing) and radiographic findings of pulmonary edema. Dogs Blood samples were collected into tubes with acid-citrate-dextrose, and platelet-pellets were obtained by centrifuge and washing steps. Platelet-proteomes were identified using LC-MS based label-free differential proteome expression analysis method and matched according to protein database for Canis lupus familiaris. Results: Totally 107 different proteins were identified in the platelets of the dogs being 4 out of them were significantly up-regulated and 6 down-regulated in acute CHF dogs. Guanine-nucleotide-binding protein, apolipoproteins (A-II and C-III) and clusterin levels increased, but CXC-motif-chemokine-10, cytochrome-C-oxidase-subunit-2, cathepsin-D, serine/threonine-protein-phosphatase-PP1-gamma-catalytic-subunit, creatine-kinase-B-type and myotrophin levels decreased in acute CHF dogs. These proteins are associated with several molecular functions, biological processes, signaling systems and immune-inflammatory responses. Conclusion: This study describes by first time the changes in the protein composition in platelets of dogs with acute CHF due to MMVD. Our findings provide a resource for increase the knowledge about the proteome of canine platelets and their roles in CHF caused by MMVD and could be a tool for further investigations about the prevention and treatment of this disease.
... MMVD was diagnosed by trans-thoracic echocardiography (CarisPlus®, color Doppler, Italy), based on the combination of following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve leaflets by 2-D echocardiography on right parasternal long-axis (RPLA) and apical 4-chamber views, and identification of mitral valve regurgitation on left apical 4-chamber view by color Doppler examination. Mitral regurgitation was also confirmed by color M-mode examination at right parasternal short axis viewmitral valve level [73,74]. ...
... The dogs with score > 4 were forwarded to echocardiographic examination for final diagnosis. Radiographic and clinical findings were interpreted in a combination with the echocardiography, providing a final diagnosis of acute CHF due to MMVD [73][74][75]. ...
Article
Full-text available
Background Platelets play a central role in the development of cardiovascular diseases and changes in their proteins are involved in the pathophysiology of heart diseases in humans. There is lack of knowledge about the possible role of platelets in congestive heart failure (CHF) in dogs. Thus, this study aimed to investigate the changes in global platelet proteomes in dogs with CHF, to clarify the possible role of platelets in the physiopathology of this disease. Healthy-dogs (n = 10) and dogs with acute CHF due to myxomatous mitral valve disease (MMVD, n = 10) were used. Acute CHF was defined based on the clinical (increased respiratory rate or difficulty breathing) and radiographic findings of pulmonary edema. Dogs Blood samples were collected into tubes with acid-citrate-dextrose, and platelet-pellets were obtained by centrifuge and washing steps. Platelet-proteomes were identified using LC-MS based label-free differential proteome expression analysis method and matched according to protein database for Canis lupus familiaris. Results Totally 104 different proteins were identified in the platelets of the dogs being 4 out of them were significantly up-regulated and 6 down-regulated in acute CHF dogs. Guanine-nucleotide-binding protein, apolipoproteins (A-II and C-III) and clusterin levels increased, but CXC-motif-chemokine-10, cytochrome-C-oxidase-subunit-2, cathepsin-D, serine/threonine-protein-phosphatase-PP1-gamma-catalytic-subunit, creatine-kinase-B-type and myotrophin levels decreased in acute CHF dogs. These proteins are associated with several molecular functions, biological processes, signaling systems and immune-inflammatory responses. Conclusion This study describes by first time the changes in the protein composition in platelets of dogs with acute CHF due to MMVD. Our findings provide a resource for increase the knowledge about the proteome of canine platelets and their roles in CHF caused by MMVD and could be a tool for further investigations about the prevention and treatment of this disease.
... CHF was staged according to the MMVD was diagnosed by trans-thoracic echocardiography (CarisPlus ® , color Doppler, Italy), based on the combination of following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve lea ets by 2-D echocardiography on right parasternal long-axis (RPLA) and apical 4-chamber views, and identi cation of mitral valve regurgitation on left apical 4-chamber view by color Doppler examination. Mitral regurgitation was also con rmed by color M-mode examination at right parasternal short axis view -mitral valve level (73,74). ...
... The dogs with score >4 were forwarded to echocardiographic examination for nal diagnosis. Radiographic and clinical ndings were interpreted in a combination with the echocardiography, providing a nal diagnosis of acute CHF due to MMVD (73)(74)(75). ...
Preprint
Full-text available
Background: Platelets play a central role in the development of cardiovascular diseases and changes in their proteins are involved in the pathophysiology of heart diseases in humans. There is lack of knowledge about the possible role of platelets in congestive heart failure (CHF) in dogs. Thus, this study aimed to investigate the changes in global platelet proteomes in dogs with CHF, to clarify the possible role of platelets in the physiopathology of this disease. Healthy-dogs (n=10) and dogs with acute CHF due to myxomatous mitral valve disease (MMVD, n=10) were used. Acute CHF was defined based on the clinical (increased respiratory rate or difficulty breathing) and radiographic findings of pulmonary edema. Dogs Blood samples were collected into tubes with acid-citrate-dextrose, and platelet-pellets were obtained by centrifuge and washing steps. Platelet-proteomes were identified using LC-MS based label-free differential proteome expression analysis method and matched according to protein database for Canis lupus familiaris. Results: Totally 104 different proteins were identified in the platelets of the dogs being 4 out of them were significantly up-regulated and 6 down-regulated in acute CHF dogs. Guanine-nucleotide-binding protein, apolipoproteins (A-II and C-III) and clusterin levels increased, but CXC-motif-chemokine-10, cytochrome-C-oxidase-subunit-2, cathepsin-D, serine/threonine-protein-phosphatase-PP1-gamma-catalytic-subunit, creatine-kinase-B-type and myotrophin levels decreased in acute CHF dogs. These proteins are associated with several molecular functions, biological processes, signaling systems and immune-inflammatory responses. Conclusion: This study describes by first time the changes in the protein composition in platelets of dogs with acute CHF due to MMVD. Our findings provide a resource for increase the knowledge about the proteome of canine platelets and their roles in CHF caused by MMVD and could be a tool for further investigations about the prevention and treatment of this disease.
... Chronic mitral valvular insufficiency (CMVI) is the most common cause of congestive heart failure (CHF) in small breed dogs [1,2] and is characterized by progressive myxomatous degeneration of the atrioventricular valves [3]. Mitral regurgitation (MR) is the most common sequel to CMVI, which causes volume overload at the left atrial (LA) and left ventricle (LV) and progresses to CHF [4]. ...
... Stage Ca (acute heart failure requiring hospitalization): The goals of therapy are to relieve the severe pulmonary edema. For dogs with pulmonary edema from acute pulmonary edema, the therapy should be directed (1) to reduce the circulating blood volume by either/both aggressive and immediate diuretic therapy (e.g., furosemide IV or CRI) and/or phlebotomy (10 ml/kg), (2) to reduce the venous return to the cardiac chambers [e.g., topical 2% nitroglycerin cream, intravenous acepromazine, intravenous sodium nitroprusside (SNP) CRI], (3) to increase oxygen saturation (e.g., oxygen tent or nasal oxygen), and (4) to strengthen myocardial systolic function (e.g., intravenous dobutamine 5-15 μg/kg/min CRI). ...
Chapter
Full-text available
Chronic mitral valvular insufficiency (CMVI) is the most common acquired heart disease in dogs and is characterized by degenerative valvular changes causing progressive thickening of mitral leaflets and incomplete closure of mitral valve. As the disease progresses, it causes congestive heart failure (CHF) and pulmonary edema if the LA dilation cannot accommodate the volume overload by mitral regurgitation. Therefore, it is the most common cause of cardiac mortality in dogs. This chapter discusses general features of CMVI in dogs focusing on recent advances in diagnosis and treatment.
... Myxomatous degeneration of the mitral valve is the most common cardiac disease in the dog (Haggstrom et al. 2004). Although this disease can be present in any breed, it is more commonly diagnosed in small-breed dogs, being the Cavalier King Charles Spaniels (CKCS) and dachshund overrepresented (Swenson et al. 1996, Olsen et al. 1999, Borgarelli & Haggstrom 2010. ...
... Although this disease can be present in any breed, it is more commonly diagnosed in small-breed dogs, being the Cavalier King Charles Spaniels (CKCS) and dachshund overrepresented (Swenson et al. 1996, Olsen et al. 1999, Borgarelli & Haggstrom 2010. Commonly referred to as myxomatous mitral valve disease (MMVD), this disease is characterised by a progressive expansion of extracellular matrix with glycosaminoglycans and proteoglycans, valvular interstitial cell alteration and attenuation or loss of the collagen-laden fibrosa layer that results in mitral valve incompetence (Haggstrom et al. 2004, Fox 2012. Mitral regurgitation is a common consequence of MMVD that leads to left atrium and ventricle volume overload (Fox 2012, Di Marcello et al. 2014) and when severe, increased left atrial pressure, pulmonary venous congestion and cardiogenic pulmonary oedema (Fox 2012, Di Marcello et al. 2014, López-Alvarez et al. 2015. ...
Article
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Objectives: To determine the efficacy and adverse events of the administration of angiotensin--converting enzyme inhibitors for the management of preclinical myxomatous mitral valve disease in dogs. Materials and methods: A compre- hensive search using Pubmed/MEDLINE, LILACS and CAB abstracts databases was performed. Ran- domised clinical trials that assessed efficacy and adverse events of angiotensin-converting enzyme inhibitors for the management of preclinical myxomatous mitral valve disease in dogs were included. Certainty of evidence was rated using GRADE methods. Results: Four randomised clinical trials were included. While safe, angiotensin-converting enzyme inhibitors administration to dogs with myxomatous mitral valve disease and cardiomegaly results in little to no difference in the risk of development congestive heart failure (high certainty of evidence; relative risk: 1.03; 95% confidence interval: 0.87 to 1.23) and may result in little to no difference in cardiovascular-related (low certainty of evidence; relative risk: 1.01; 95% confidence interval: 0.54 to 1.89) and all-cause mortality (low certainty of evidence; relative risk: 0.93; 95% confidence interval: 0.63 to 1.36). Administration of angiotensin-converting enzyme inhibitors to dogs with myxomatous mitral valve disease without cardiomegaly may result in a reduced risk of congestive heart failure development. However, the range in which the actual effect for this outcome may be, the "margin of error," indicates it might also increase the risk of congestive heart failure development (low certainty of evidence; relative risk: 0.86; 95% confidence interval: 0.54 to 1.35). Clinical significance: Administration of angiotensin-converting enzyme inhibitors to dogs with -preclinical myxoma- tous mitral valve disease and cardiomegaly results in little to no difference in the risk of the develop- ment of congestive heart failure and may result in little to no difference in -cardiovascular-related and all-cause mortality. The certainty of evidence of the efficacy of angiotensin-converting enzyme inhibi- tors administration to dogs without cardiomegaly was low.
... Alguns autores têm sugerido que a doença pode aparecer por fatores genéticos, traumatismo torácico, endocardite bacteriana e prolapso valvar mitral (3,4). Estima-se que seja responsável por 75% a 80% das cardiopatias, sendo a prevalência dependente da idade, acometendo de 1 a 5% dos cães jovens e por volta de 75% de cães idosos (1,(3)(4)(5)(8)(9)(10). A degeneração valvar mitral crônica (DVMC) aumenta quase que de forma linear conforme a idade, aproximadamente 10% dos cães com 6 anos de idade apresentam esta patologia, sendo que este índice se eleva para 60% quando a idade é aumentada para 12 anos (11). ...
Article
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RESUMO Atualmente a incidência de cães portadores de degeneração de valva mitral é crescente. Observa-se, portanto, um aumento no número de procedimentos cirúrgicos nesses pacientes em clínicas e hospitais veterinários. Dessa forma, o conhecimento da fisiopatologia da doença, assim como a ação farmacológica dos anestésicos sobre o sistema cardiovascular é imprescindível. Destacam-se nesta revisão os fenotiazínicos, benzodiazepínicos e opióides como agentes pré-anestésicos ou de indução; o tiopental, propofol e etomidato como agentes de indução intravenosos e o halotano, isofluorano e sevofluorano como agentes voláteis seguros para cardiopatas. Palavras-chave: procedimento anestésico, cardiopatias, alterações hemodinâmicas, canino. ANESTHESIA IN DOGS WITH DEGENERATIVE MITRAL VALVE – REVIEW ABSTRACT Currentely the incidence of dogs with degenerative mitral valve is increasing. It´s observed, so, an increase of surgical procedures due to the improvement of anesthesic technique and monitoring in these animals. Thus, the knowledge about the disorder´s physiopathology, such as the anesthesic´s pharmacological action on the cardiovascular system, are essential. In this review could be highlighted phenothiazines, benzodiazepines and opioids as pre-anesthesics or induction agents. The thiopental, propofol, and etomidate as intravenous induction agents and the halotane, isofluorane and sevofluorane as safe volatile agents for patients with cardiac disease.
... Myxomatous mitral valve disease (MMVD) involves a progressing degeneration of the valve leaflets resulting in mitral regurgitation and left atrial and ventricular enlargement [7]. ...
Article
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Background Dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD) are the most common diseases noted in dogs. Although their pathogenesis varies, both include a significant enlargement of the left atrium.The study was carried out on left atrial specimens obtained from 56 dogs, including those from 34 dogs with clinically diagnosed MMVD, 15 dogs with DCM and 7 dogs without heart disease (control group). Dogs in the MMVD and the DCM groups presented with left atrial enlargement and stage D heart failure. The specimens underwent immunohistochemical examination using desmin, vimentin, periostin and caspase-3 antibodies. ResultsThere were alterations in the expression of the studied proteins in the study groups compared to the control group. The changes included: irregularity of desmin cross-striation and desmosomes, a higher amount of vimentin-positive cells, a change in the periostin expression pattern from cytoplasmic to extracellular, and a lower expression of caspase-3. The alterations were more pronounced in the DCM group than in the MMVD group. Conclusions During heart failure, the pattern of desmin, vimentin, periostin and caspase-3 expression alters in the left atrium, regardless of the cause. The changes are more pronounced in dogs with DCM than in dogs with MMVD and similar left atrial enlargement, suggesting that volume overload may not be the only cause of myocardial changes in DCM.
... Cavalier King Charles spaniels, Yorkshire terriers, dachshunds) and progresses with age [12][13][14]. The progressive dilation of the left ventricle and the left atrium in CMVD results from degenerative changes and an insufficiency of the mitral valve, leading to symptoms of heart failure [15]. Histopathologic changes within the ventricular walls include fibrosis and arteriosclerosis without or with slight myocyte atrophy [16,17]. ...
Article
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Dilated cardiomyopathy (DCM) and chronic mitral valve disease (CMVD) in dogs are associated with heart chamber enlargement, also of the left atrium. DCM is often accompanied by rhythm disturbances (mainly atrial fibrillation or ventricular arrhythmias). In CMVD, arrhythmias are observed less frequently. It is still unclear whether left atrial enlargement in these diseases results from volume overload or if it is also connected with other factors (e.g. rhythm disturbances). This study was conducted on the left atrial myocardial specimens from 31 dogs, including those from 16 dogs with clinically diagnosed DCM and 15 dogs with CMVD. After fixation and staining (using haematoxylin-eosin and Masson-Goldner trichrome stain), the specimens underwent evaluation. Parenchymal changes (fibrosis, fatty infiltration, and vessel narrowing), degenerative changes (loss of striation, changes in cardiomyocyte structure, and abnormal cell nuclei) and the presence of inflammatory infiltrates were assessed. More interstitial fibrosis (median 4 vs. 2.5 grid fields; p < 0.05) and less perivascular fibrosis (median score 1 vs. 2; p < 0.05) was observed in the DCM group compared to the CMVD group. Moreover, less distinct vessel narrowing was observed in the DCM group than in the CMVD group (median lumen area ratio 0.3 vs. 0.26 respectively; p < 0.05). Dogs with DCM showed more strongly defined degenerative changes than the CMVD dogs (median nuclei enlargement score 3 vs. 1, median loss of striation score 3 vs. 2 and median structural alterations score 3 vs. 2, respectively; p < 0.05). The obtained results indicate a different nature of changes occurring in the left atrial myocardium of dogs with DCM compared to dogs with mitral valve disease, including differences in vessel narrowing, cardiomyocyte degeneration and in the distribution of connective tissue.
... Myxomatous mitral valve disease (MMVD) is the most common acquired cardiac disease of the dog and is a major cause of morbidity and mortality in this species (Darke, 1987;Beardow and Buchanan, 1993;Hamlin et al., 1996;Haggstrom et al., 2004). Much is known about the diagnosis and treatment of MMVD, but only recently has attention focussed on a better understanding the pathobiology of this disease. ...
Article
Myxomatous mitral valve disease (MMVD) is the single most common acquired heart disease of the dog, but is also of emerging importance in human medicine, with some features of the disease shared between both species. There has been increased understanding of this disease in recent years, with most research aiming to elucidate the cellular and molecular events of disease pathogenesis. For gross and histological changes, much of our understanding is based on historical studies and there has been no comprehensive reappraisal of the pathology of MMVD. This paper reviews the gross, histological, ultrastructural, cellular and molecular changes in canine MMVD.
... The most represented breed of dogs in the DMVD group was Poodle (8/16). This is different from other DMVD studies in Europe and USA in which the most common breeds were Cavalier King Charles spaniels and Dachshunds (Häggström et al., 2004;Häggström et al., 2005). It is probably because Poodle is the most popular breed in Thailand particularly in the metropolitan area. ...
Article
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Degenerative mitral valve disease (DMVD) is the major cause of mitral valve regurgitation and heart failure in dogs. The regurgitation of mitral valve may affect blood pressure without clinical presentation. The aims of this study were to compare the systolic blood pressure between normal dogs and dogs affected with asymptomatic DMVD (class B ACVIM classification) and to determine the relationship between echocardiographic values and blood pressure levels. The systolic blood pressure of small breed dogs, weighing less than 10 kilogram, that were normal (n=22) and newly diagnosed with DMVD (n=21) was measured. The average of systolic blood pressure determined by Doppler ultrasonic device and Oscillometer of dogs in the DMVD group was higher than that of the normal group. Three DMVD dogs had systolic blood pressure higher than 160 mmHg. The echocardiographic values did not correlate with blood pressure. In conclusion, blood pressure of asymptomatic DMVD dogs is maintained. Some diseased dogs may have systolic blood pressure higher than normal limit.
... The majority of the panelists recommended the administration of β-blockers, digoxin, or diltiazem as antiarrhythmics, and cough suppressants and bronchodilators in the presence of cough. In this decade, the attention to dogs' diets increased, with particular interest for sodium restriction [253][254][255][256][257]. The reviews published in these ten years are much more numerous than in previous years because more studies were carried out to evaluate the therapy of CHF secondary to MMVD in dogs [237,247,[258][259][260][261][262][263][264]; these data are important because the reviews identify, evaluate, and summarize the outcomes of the studies carried out in a specific period. ...
Article
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The treatment of chronic congestive heart failure (CHF), secondary to myxomatous mitral valve disease (MMVD) in dogs, has considerably changed in the last fifty years. An analysis of the literature concerning the therapy of chronic CHF in dogs affected by MMVD is not available, and it is needed. Narrative reviews (NRs) are aimed at identifying and summarizing what has been previously published, avoiding duplications, and seeking new study areas that have not yet been addressed. The most accessible open-access databases, PubMed, Embase, and Google Scholar, were chosen, and the searching time frame was set in five decades, from 1970 to 2020. The 384 selected studies were classified into categories depending on the aim of the study, the population target, the pathogenesis of MMVD (natural/induced), and the resulting CHF. Over the years, the types of studies have increased considerably in veterinary medicine. In particular, there have been 43 (24.29%) clinical trials, 41 (23.16%) randomized controlled trials, 10 (5.65%) cross-over trials, 40 (22.60%) reviews, 5 (2.82%) comparative studies, 17 (9.60%) case-control studies, 2 (1.13%) cohort studies, 2 (1.13%) experimental studies, 2 (1.13%) questionnaires, 6 (3.40%) case-reports, 7 (3,95%) retrospective studies, and 2 (1,13%) guidelines. The experimental studies on dogs with an induced form of the disease were less numerous (49–27.68%) than the studies on dogs affected by spontaneous MMVD (128–72.32%). The therapy of chronic CHF in dogs has considerably changed in the last fifty years: in the last century, some of the currently prescribed drugs did not exist yet, while others had different indications.
... Echocardiographic assessment of systolic function in dogs with MMVD is confounded by the effects of MR on LV loading conditions, although systolic dysfunction is detected much more commonly in large breed dogs with severe MMVD than small breed dogs. 24,35,36 Also in agreement with previous studies, high values of mitral E vel had important prognostic value. This is a relatively easy echocardiographic measurement to obtain, with good repeatability in our study. ...
Article
To evaluate vena contracta and other echocardiographic measures of myxomatous mitral valve disease (MMVD) severity in a multivariable analysis of survival in dogs. 70 dogs diagnosed with MMVD from stored echocardiographic images that met study inclusion criteria. Left heart dimensions were measured as well as mitral regurgitant jet area/left atrial area (JAR), early mitral filling velocity (Evel), extent of mitral valve prolapse in right and left views (ProlR, ProlL), Prol indexed to aortic diameter (ProlR:Ao, ProlL:Ao), presence of a flail leaflet (FlailR, FlailL), and mitral regurgitation vena contracta diameter (VCR, VCL) indexed to aortic diameter (VCR:Ao, VCL:Ao). Follow-up from referring veterinarians was obtained by questionnaire or telephone to determine survival times. Inter- and intra-observer agreement was evaluated with Bland-Altman plots and weighted Kappa analysis. Survival was analyzed using Kaplan-Meier curves, logrank tests and Cox's proportional hazards. Logrank analysis showed VCL:Ao, VCR:Ao, FlailL, ProlR:Ao, ProlL:Ao, left ventricular internal dimension in diastole indexed to aortic diameter (LVIDD:Ao) >2.87, left atrium to aorta ratio (LA/Ao) >1.6, and Evel >1.4 m/s were predictors of cardiac mortality. In a multivariable analysis, the independent predictors of cardiac mortality were Evel >1.4 m/s [hazard ratio (HR) 5.0, 95% confidence interval (CI) 2.5-10.3], FlailL (HR 3.1, 95% CI 1.3-7.9), and ProlR:Ao (HR 2.8, 95% CI 1.3-6.3). Echocardiographic measures of mitral regurgitation severity and mitral valve pathology provide valuable prognostic information independent of chamber enlargement in dogs with MMVD. Copyright © 2014 Elsevier B.V. All rights reserved.
... MR is strongly associated with disease severity and leads to altered cardiac blood flow and increased shear stress (Garcia et al., 1996). With disease progression, haemodynamic changes cause volume overload and myocardial remodelling (Buchanan, 1977;Haggstrom et al., 2004). ...
... Dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD) are the most common cardiac disorders in large (DCM) or small (MMVD) breed dogs. They are both accompanied by heart enlargement, including mostly left ventricle and left atrium, although the pathomechanisms of these changes seem to vary between both diseases [1][2][3][4][5]. MMVD involves a progressing degeneration of mitral valve leaflets, which results in an increased mitral regurgitation blood flow. ...
Article
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Introduction: Dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD) are common heart conditions in dogs. They have different etiology and pathogenesis and although other studies focused on changes in the left ventricles of the affected hearts, the aim of our study was to assess the expressions of some intrinsic proteins in the enlarged left atria. Material and methods: We performed an immunohistochemical analysis of left atrial specimens obtained from 15 dogs with DCM, 35 dogs with MMVD and six control dogs. We assessed the expression of following proteins: SERCA1, SERCA2, sarcomeric actinin, smooth muscle actin, and dystrophin. Results: We noted a higher percentage of SERCA1-positive cells in the MMVD group and lower percentage of dystrophin-positive cells in the DCM group as compared to control group. The expression of other proteins was similar in the hearts of control dogs and dogs with heart diseases. Conclusions: The observed changes in the expression patterns of some proteins in the atria of dogs with DCM and MMVD suggest that atrial enlargement relies not only on volume overload, but also alterations of the intrinsic proteins can contribute to the pathogenesis of dilated cardiomyopathy.
... In most cases atrioventricular valvulopathy occurs in the dog spontaneously and is age-related [1][2][3]. ...
Article
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Background Endocardiosis is the most common heart disease in Dachshunds and is therefore an important cause of cardiac morbidity and death. In recent years we have observed an increasing interest in the development of new genetic and genomic markers of heart disease. The discovery of miRNAs circulating in biofluids such as plasma or serum aroused researchers¿ interest in using them as potential biomarkers. In the present study we analysed the expression of 9 miRNAs described in literature as being involved in cardiovascular pathology in the plasma of dogs suffering from endocardiosis.ResultsExpression analysis using the Real-time PCR method revealed that two out of nine miRNAs were significantly down regulated: the expression of miR-30b differed between ACVIM stage B and stage A (control) dogs; the expression of mi-133b differed ACVIM stage C and stage A dogs. 5 miRNAs (miR-125, miR-126, miR-21, miR-29b and miR-30b) showed a trend of down regulation in the ACVIM C group. Levels of miR-423 were the same in healthy and diseased dogs. Expression of miR-208a and 208b was not detected.ConclusionsmiR-30b could be a potential biomarker of ACVIM stage B heart failure in Dachshunds with endocardiosis and miR-133b could be a potential biomarker of ACVIM stage C. The lack of expression or lack of significant changes in expression in 7 miRNAs which are potential biomarkers of heart diseases in humans proves that findings from human medicine are not always directly reflected in veterinary medicine.
... There is an increase in incidence with age, and most affected dogs are small breeds [1]. Progressive collagen degeneration and accumulation of acid mucopolysaccharide at the free edges of the mitral leaflets lead to thickening, deformation, and dysfunction of the valve and chorda tendinea [2,3]. The pathological changes give rise to mitral regurgitation leading to a gradually increasing chronic volume load on the left side of the heart, resulting in clinically detectable left atrial and/or left ventricular enlargement. ...
Article
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MMVD, the most common cause of CHF in dogs, is a chronic disease with variable clinical signs, with some patients remaining asymptomatic while others develop CHF. Here, we aimed to evaluate serum proteins by proteomic analysis in dogs at different stages of CHF due to MMVD, and proteome behaviors after conventional treatment. A total of 32 dogs were divided equally into four groups—stage A (healthy/controls), stage B2 (asymptomatic), stage C and stage D (symptomatic)—according to the ACVIM consensus. Serum proteomes were evaluated using LC/MS-based label-free differential proteome analysis. The study revealed 157 different proteins; 11 were up- and 21 down-regulated in dogs with CHF compared to controls. In stage B2 dogs, angiotensinogen (AGT) was up-regulated, but immunoglobulin iota chain-like, lipopolysaccharide-binding protein, and carboxypeptidase (CPN) were down-regulated. In stage C dogs, complement C3 (C3) and inter-alpha-trypsin inhibitor heavy chain were up-regulated, but hemopexin, and actin-cytoplasmic-1 (ACT-1) were down-regulated. In stage D dogs, AGT was up-regulated, whereas tetranectin, paraoxonase-1, adiponectin and ACT-1 were down-regulated. A decrease in CPN, C3 and AGT and an increase in ACT-1 were observed after treatment of dogs in stage C. This pilot study identified that dogs at different stages of CHF show different serum protein composition which has potential to be biomarker for diagnose and treatment monitorization.
... The prevalence of MMVD increases with age. 1 More than 30% of small breed dogs !10 years old have clinically detected signs of MMVD (i.e. heart murmur). 2 Males are often more affected by this disease than females. ...
Article
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Objectives Serotonin has been implicated in canine myxomatous mitral valve disease (MMVD); however, the sources of serotonin have not been fully elucidated. This study compared the concentration of serotonin in plasma and platelets of normal healthy small breed dogs with predisposition to MMVD and dogs with naturally occurring MMVD. Animals 43 small-breed client-owned dogs with an approximate weight of < 10kg and age of 6 years or above were divided into 2 groups: a healthy control group (n=20) and a group with echocardiographic evidence of MMVD (n=23). Methods 5ml samples of blood were collected. Plasma and platelets were separated by centrifugation and assayed for serotonin measured by enzyme linked immunosorbent assay (ELISA). Results Median plasma serotonin concentration was not significantly different (p=0.3630) between normal healthy dogs (3.7 ng/ml) and dogs with MMVD (4.3 ng/ml). Males had higher plasma serotonin concentration than females (4.7 and 2.9 ng/ml respectively, p=0.0043). Platelet serotonin concentration was not different between healthy dogs and dogs with MMVD (128.6 ng/109 platelets and 176.6 ng/109 platelets respectively, p=0.4575). Age, echocardiographic indices and platelet count showed no correlation with plasma or platelet serotonin concentration. Conclusions Circulating plasma serotonin is unlikely a major source of serotonin signaling in canine MMVD. Platelets could be a source of serotonin in canine MMVD through platelet adhesion to the mitral valve; however, the amount of serotonin stored in platelets of healthy dogs and dogs with MMVD is not different.
... Stage B includes two subgroups (B1 and B2); asymptomatic and presence of heart murmur with (B2) or without cardiomegaly (B1). In this study, only B2 dogs (n = 6) were selected, which was characterized by the presence of heart murmur at mitral valve puncta maxima, and radiographic (vertebral heart (19,20). ...
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Background: Heart failure (HF) has been associated with changes in inflammatory and oxidative-stress biomarkers. This study aimed to evaluate the changes of a panel of inflammatory and oxidative stress biomarker in dogs with different stages of HF and its relation with the severity of the disease and the echocardiographic changes. Dogs with HF as a result of myxomatous mitral valve degeneration or dilated cardiomyopathy were included. A total of 29 dogs were classified as stage-A (healthy), B (asymptomatic dogs), C (symptomatic dogs) and D (dogs with end-stage-HF) according to the ACVIM-staging-system. Serum cytokines, and inflammatory and oxidative stress markers were evaluated. Results: KC-like as an inflammatory cytokine was significantly increased in dogs of stage-C (P < 0.01) and -D (P < 0.05) compared with stage-A and -B. Stage-D Dogs showed significantly higher serum CRP and Hp (P < 0.05) but lower serum anti-oxidant capacity (PON1, TEAC, CUPRAC, and thiol) compared to stage-A and -B (P < 0.05). After the treatment, serum levels of CRP, Hp and KC-like decreased but serum anti-oxidant levels increased compared to their pre-treatment values. Left ventricular dimension and LA/Ao ratio correlated positively with CRP, MCP-1, and KC-like but negatively with PON1, GM-CSF, IL-7 and antioxidant biomarkers (P < 0.01). Conclusion: our results indicated that dogs with advanced-stages of HF show increases in positive acute-phase proteins and selected inflammatory cytokines (KC-like), and decreases in antioxidant biomarkers, indicating that inflammation and oxidative-stress act as collaborative partners in the pathogenesis of HF. KC-like may be a more useful parameter to monitor disease progression and treatment efficacy of dogs with severe-HF.
... La enfermedad degenerativa valvular (EDV), endocardiosis o enfermedad valvular crónica, es la patología cardiovascular con mayor prevalencia, 75% de los pacientes caninos llevados a consulta cardiológica son diagnosticados en diferentes estadios de la enfermedad 2,9,11,14 . La EDV se presenta con mayor frecuencia en animales adultos (>7 años), de razas pequeñas como Poodle estándar y miniatura, Schnauzer, Pinscher, entre otras y mestizos menores de 15 kg. ...
Article
p>El objetivo de esta investigación fue determinar los cambios histopatológicos de las aletas valvulares compatibles con enfermedad degenerativa valvular (EDV) en perros que al examen clínico se encontraban asintomáticos. La muestra fue de 38 corazones obtenidos en el Centro de Adopción y Tenencia de Mascotas de Bogotá sometidos al procedimiento de eutanasia como parte del control poblacional en el programa distrital contra la rabia. El 57,9% de los animales correspondieron a machos y el 42,1% a hembras, principalmente mestizos (n= 21), Poodle (n= 15), Cocker Spaniel (n= 1) y Schnauzer (n= 1). El peso promedio fue de 7,34 ± 2,44 kg (3–13 kg) y la edad promedio aproximada por evaluación dentaria fue 7 ± 3 años (2–15 años). Clínicamente, los animales no presentaron signos de compromiso cardíaco. La interpretación de los cambios histopatológicos se basó en la clasificación Kogure. Con la coloración de hematoxilina y eosina se encontró que un 65,8% de las válvulas septales mitrales y el 68,4% de las laterales presentaron cambios compatibles con EDV al igual que el 55,3% de las septales tricuspídeas y el 84,2% de las laterales. Con la coloración alcian blue, especial para evaluar tejido conectivo, se encontró que el 76,3% de las aletas septales mitrales y el 76,3% de las laterales presentaron cambios compatibles con EDV. De igual manera al evaluar el aparato tricuspídeo se encontró que el 68,4% de sus aletas septales y el 65,8% de las laterales presentaron estos cambios. Esto demuestra que las lesiones del tejido valvular empiezan antes de la aparición del signo más frecuente de esta enfermedad que es el soplo. Por lo tanto se evidencia la necesidad de empezar a diseñar programas de medicina preventiva para reducir el riesgo de morbilidad y mortalidad de esta enfermedad debida a la remodelación ventricular como consecuencia de la activación neurohormonal temprana. </p
... Histological studies of myxomatous mitral valves from affected humans and susceptible dog breeds have identified the abnormal presence of SMA-positive VICs within the affected tissue at the end-stage [9,[25][26][27][28]. Based on this molecular profile, these VICs have been termed "activated" and designated for their myofibroblast-like characteristics [29]. ...
Article
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Background: Mitral valve prolapse (MVP) affects 3-6% of the total population including those with connective tissue disorders. Treatment is limited, and patients commonly require surgery which can be impermanent and insuperable. Abnormal prolapse of mitral valve leaflets into the left atria is caused by disturbances to the composition and organization of the extracellular matrix (ECM), that weaken biomechanics. This process, known as myxomatous degeneration is characterized by an abnormal accumulation of proteoglycans, in addition to collagen fiber disruption and elastic fiber fragmentation. The underlying mechanisms that promote myxomatous degeneration to the point of biomechanical failure are unknown, but previous histological studies of end-stage diseased tissue have reported abnormal α-smooth muscle actin (SMA) in a subset of heart valve interstitial cells (VICs); however, the contribution of these abnormal cells to MVP pathogenesis has not been extensively examined. Methods: In vivo and in vitro approaches were used. Mice harboring a Fbn1C1039G mutation mimic human Marfan Syndrome and develop MVP. Using these mice, temporal and spatial changes in SMA expression relative to myxomatous degeneration were examined using histological techniques. In parallel in vitro experiments, SMA expression was downregulated in primary porcine mitral VICs directly using siRNA, and indirectly using the actin depolymerizing agent Latrunculin A. In addition, the regulation of SMA in VICs by mechanical stiffness was explored relative to ECM remodeling. Results: We show, in mitral valves from Fbn1C1039G/+ mice, that abnormal increases in SMA expression in VICs are evident during early postnatal stages of disease, prior to significant myxomatous degeneration as indicated at later stages by increased proteoglycans and collagen type I (Col1a1). Furthermore, abnormal SMA expression continues to increase during the course of pathogenesis and is localized to the mid belly region of the mitral valve leaflets from 10 weeks. Using an in vitro approach, we demonstrate that reduced SMA function by direct siRNA or indirect Latrunculin A treatment attenuates proteoglycan and Col1a1 expression in porcine mitral VICs. While upstream, we provide insights to show that SMA is regulated by mechanical tension in VICs to promote changes in ECM homeostasis. Conclusions: Together, our data show that in VICs, SMA, an actin binding protein, is important for mediating ECM remodeling associated with phenotypes observed in myxomatous degeneration, and its expression is regulated by mechanical tension. These novel insights could inform the development of future non-surgical therapeutics to halt the progression of mitral valve degeneration thereby avoiding end-stage prolapse.
... The diagnosis of MMVD was based on the combination of following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve lea ets by 2-D echocardiography on right parasternal long-axis view, and identi cation of mitral valve regurgitation on left apical 4-chamber view by color Doppler examination (46,47). ...
Preprint
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Background: Heart failure (HF) has been associated with changes in inflammatory and oxidative-stress biomarkers. This study aimed to evaluate the changes of a panel of inflammatory and oxidative stress biomarker in dogs with different stages of HF and its relation with the severity of the disease and the echocardiographic changes. Dogs with HF as a result of myxomatous mitral valve degeneration or dilated cardiomyopathy were included. A total of 29 dogs were classified as stage-A (healthy), B (asymptomatic dogs), C (symptomatic dogs) and D (dogs with end-stage-HF) according to the ACVIM-staging-system. Serum cytokines, and inflammatory and oxidative stress markers were evaluated. Results: KC-like as an inflammatory cytokine was significantly increased in dogs of stage-C (P<0.01) and -D (P<0.05) compared with stage-A and -B. Stage-D Dogs showed significantly higher serum CRP and Hp (P<0.05) but lower serum anti-oxidant capacity (PON1, TEAC, CUPRAC, and thiol) compared to stage-A and -B (P<0.05). After the treatment, serum levels of CRP, Hp and KC-like decreased but serum anti-oxidant levels increased compared to their pre-treatment values. Left ventricular dimension and LA/Ao ratio correlated positively with CRP, MCP-1, and KC-like but negatively with PON1, GM-CSF, IL-7 and antioxidant biomarkers (P<0.01). Conclusion: our results indicated that dogs with advanced-stages of HF show increases in positive acute-phase proteins and selected inflammatory cytokines (KC-like), and decreases in antioxidant biomarkers, indicating that inflammation and oxidative-stress act as collaborative partners in the pathogenesis of HF. Some of these biomarkers of inflammation and oxidative stress could be tested as new biomarkers to monitor the severity of the disease and the effect of treatment.
... The diagnosis of MMVD was based on the combination of following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve leaflets by 2-D echocardiography on right parasternal longaxis view, and identification of mitral valve regurgitation on left apical 4-chamber view by color Doppler examination [48,49]. ...
Article
Full-text available
Background Heart failure (HF) is associated with changes in inflammatory and oxidative stress biomarkers. This study aimed to evaluate the changes of a panel of inflammatory and oxidative stress biomarkers in dogs with different stages of HF and its relation with the severity of the disease and echocardiographic changes. A total of 29 dogs with HF as a result of myxomatous mitral valve degeneration or dilated cardiomyopathy were included and classified as stage-A (healthy), B (asymptomatic dogs), C (symptomatic dogs) and D (dogs with end-stage HF) according to the ACVIM staging system. In these dogs an ecnhocardiographic examination was performed and cytokines, and inflammatory and oxidative stress markers were evaluated in serum. Results KC-like was significantly increased in dogs of stage-C (P < 0.01) and -D (P < 0.05) compared with stage-A and -B. Stage-D dogs showed significantly higher serum CRP and Hp (P < 0.05) but lower serum antioxidant capacity (PON1, TEAC, CUPRAC, and thiol) compared to stage-A and -B (P < 0.05). After the treatment, serum levels of CRP, Hp and KC-like decreased and serum antioxidant levels increased compared to their pre-treatment values. Left ventricular dimension and LA/Ao ratio correlated positively with CRP, MCP-1, and KC-like but negatively with PON1, GM-CSF, IL-7 and antioxidant biomarkers (P < 0.01). Conclusion Our results showed that dogs with advanced HF show increases in positive acute-phase proteins and selected inflammatory cytokines such as KC-like, and decreases in antioxidant biomarkers, indicating that inflammation and oxidative stress act as collaborative partners in the pathogenesis of HF. Some of these biomarkers of inflammation and oxidative stress could have the potential to be biomarkers to monitor the severity of the disease and the effect of treatment.
... The diagnosis of MMVD was based on the combination of following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve lea ets by 2-D echocardiography on right parasternal long-axis view, and identi cation of mitral valve regurgitation on left apical 4-chamber view by color Doppler examination (46,47). ...
Preprint
Full-text available
Background: Heart failure (HF) has been associated with changes in inflammatory and oxidative-stress biomarkers. This study aimed to evaluate the changes of a panel of inflammatory and oxidative stress biomarker in dogs with different stages of HF and its relation with the severity of the disease and the echocardiographic changes. Dogs with HF as a result of myxomatous mitral valve degeneration or dilated cardiomyopathy were included. A total of 29 dogs were classified as stage-A (healthy), B (asymptomatic dogs), C (symptomatic dogs) and D (dogs with end-stage-HF) according to the ACVIM-staging-system. Serum cytokines, and inflammatory and oxidative stress markers were evaluated. Results: KC-like as an inflammatory cytokine was significantly increased in dogs of stage-C (P<0.01) and -D (P<0.05) compared with stage-A and -B. Stage-D Dogs showed significantly higher serum CRP and Hp (P<0.05) but lower serum anti-oxidant capacity (PON1, TEAC, CUPRAC, and thiol) compared to stage-A and -B (P<0.05). After the treatment, serum levels of CRP, Hp and KC-like decreased but serum anti-oxidant levels increased compared to their pre-treatment values. Left ventricular dimension and LA/Ao ratio correlated positively with CRP, MCP-1, and KC-like but negatively with PON1, GM-CSF, IL-7 and antioxidant biomarkers (P<0.01). Conclusion: our results indicated that dogs with advanced-stages of HF show increases in positive acute-phase proteins and selected inflammatory cytokines (KC-like), and decreases in antioxidant biomarkers, indicating that inflammation and oxidative-stress act as collaborative partners in the pathogenesis of HF. Some of these biomarkers of inflammation and oxidative stress could be tested as new biomarkers to monitor the severity of the disease and the effect of treatment.
... The gold standard for the de nitive diagnosis of PH is cardiac catheterization of the right heart to measure the pulmonary arterial pressure (PAP) directly in the pulmonary vasculature (8), but in general veterinary practice, echocardiography is more generally used in the diagnosis of PH, as well as in MVD (9,10). However, there are some limitations to this technique, including the high cost of the echocardiography machine and the need for a well-trained sonographer to perform the procedure. ...
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Background Pulmonary hypertension (PH) is an important complication in dogs with cardiorespiratory diseases. The most common underlying disease of PH has been described to be mitral valve disease (MVD), which is the most frequent acquired heart disease found in dogs. Doppler echocardiography is generally used in routine practice for identifying PH; however, there are several limitations to this method in practical use. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a technique that can characterize specific patterns of peptide mass called peptide barcodes from various samples. In addition, in combination with liquid chromatography tandem mass spectrometry (LC-MS/MS), potential peptide sequences associated with specific conditions could be identified. The present study aimed to use MALDI-TOF coupled with LC-MS/MS to characterize specific peptide barcodes and potential peptide candidates in serum samples from healthy dogs (normal control), dogs with MVD stage B (MVD B) (asymptomatic stage), MVD stage C (MVD C) (symptomatic stage), MVD stage B with PH (MVD B PH) and MVD stage C with PH (MVD C PH). Results Discrete clusters of the 5 sample groups were identified by 3D plot analysis. Peptide barcodes also revealed differences in peptide patterns among the 5 groups. Six amino acid sequences of peptide candidates at 1,225.60, 1,363.85, 1,688.71, 1789.52, 2020.21 and 2156.42 Da were identified as part of the proteins CLCN1, CLUL1, EDNRA, PTEN, SLC39A7, and CLN6, respectively. The network interactions between these discovered proteins and common cardiovascular drugs were also investigated. Conclusion The present study revealed distinct clusters and different peptide barcodes for the MVD B, MVD C, MVD B PH, MVD C PH and normal control groups using MALDI-TOF MS. These results demonstrate that MALDI-TOF MS has promise as a technique for diagnosing dogs affected by asymptomatic and symptomatic stages of MVD with and without PH. Additionally, with MALDI-TOF MS in combination with LC-MS/MS, potential peptide candidates related to diseases were also identified. Further studies are required to identify peptide barcodes in dogs with other diseases to create peptide barcode databases in veterinary medicine before using this method as a novel diagnostic tool in the future.
... The gold standard for the definitive diagnosis of PH is cardiac catheterization of the right heart to measure the pulmonary arterial pressure (PAP) directly in the pulmonary vasculature [11], which is not practical in general veterinary practice. Alternatively, echocardiography is promising in the diagnosis of PH [12,13]. However, this technique has some limitations, including; the need for flow velocity of tricuspid or pulmonic regurgitation, which can be absent in some patients, poor alignment of the interrogation beam to the blood flow direction, poor cooperation of patients during the procedure, and skill and experience of sonographers [10]. ...
Article
Full-text available
Mitral valve disease (MVD) is an important and most frequently acquired heart disease found in dogs. MVD is classified into different stages according to its severity. There is a challenge in differentiation between asymptomatic and symptomatic stages of the MVD. Moreover, pulmonary hypertension (PH) is a common complication in dogs affected by MVD. In clinical practice, there are also some limitations to identify PH. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a technique that can characterize specific patterns of peptide mass called peptide barcodes from various samples. Besides, in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS), potential peptide sequences associated with specific conditions could be identified. The present study aimed to use MALDI-TOF coupled with LC-MS/MS to characterize specific peptide barcodes and potential peptide candidates in serum samples from healthy dogs, dogs with MVD stage B (MVD B, asymptomatic stage), MVD stage C (MVD C, symptomatic stage), MVD stage B with PH (MVD B PH), and MVD stage C with PH (MVD C PH). Discrete clusters of the 5 sample groups were identified by 3D plot analysis. Peptide barcodes also revealed differences in peptide patterns among the 5 groups. Six amino acid sequences of peptide candidates at 1,225.60, 1,363.85, 1,688.71, 1789.52, 2020.21, and 2156.42 Da were identified as part of the proteins CLCN1, CLUL1, EDNRA, PTEN, SLC39A7, and CLN6, respectively. The network interactions between these discovered proteins and common cardiovascular drugs were also investigated. These results demonstrate that MALDI-TOF MS has promise as an optional technique for diagnosing dogs affected by asymptomatic and symptomatic stages of MVD with and without PH. Further studies are required to identify peptide barcodes in dogs with other diseases to create peptide barcode databases in veterinary medicine before using this method as a novel diagnostic tool in the future.
... Canine MMVD presents similarities with the human disease and results predominantly in valvular insufficiency, blood regurgitation, subsequent left-sided volume overload, and finally, congestive heart failure [2,3]. Dogs affected by the disease may have a long preclinical period that could last for years prior to developing clinical signs, with progressive worsening of the pathology [4][5][6]. ...
Article
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Myxomatous mitral valve degeneration (MMVD) is the most common acquired cardiac disease in canine species, and valvular interstitial cells (VICs) are considered the main responsible for the development of this pathology. The scientific interest is focused on isolating and characterizing these cells. The aims of the present study were to verify a novel VICs mechanical isolation method and to characterize isolated cells using immunocytochemistry and immunofluorescence, with parallel histological and immunohistochemistry assays on bovine and canine healthy and MMVD mitral valves. Antibodies against vimentin (VIM), smooth muscle actin (SMA), von Willebrand (vW) factor, Transforming Growth Factor (TGF) β1, and Transient Receptor Potential Vanilloid 1 (TRPV1) were used. The isolation method was considered reliable and able to isolate only VICs. The different assays demonstrated a different expression of SMA in healthy and MMVD mitral valves, and TRPV1 was isolated for the first time from bovine and canine VICs and the correspondent mitral valve leaflets. The novelties of the present study are the new isolation method, that may allow correlations between laboratory and clinical conditions, and the identification of TRPV1, which will lead to further investigations to understand its function and possible role in the etiology of MMVD and to the design of new therapeutic strategies.
... La enfermedad valvular degenerativa (EVD), endocardiosis o enfermedad valvular crónica es la patología cardiovascular con mayor prevalencia; 75% de los pacientes caninos llevados a consulta cardiológica son diagnosticados en diferentes estadios de la enfermedad Häggström et al., 2004;Gómez, 2004;Kittleson, 1999). La presentación clínica de la EVD ocurre con mayor frecuencia en animales adultos (>7 años), de razas pequeñas como: Poodle estándar y miniatura, Schnauzer, Pincher, entre otras y criollos menores de 15 kg. ...
Article
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Degenerative valve disease is the main cardiovascular abnormality in dogs. This injury consists of microscopic lesions of the valve, due to mucopolysaccharide infiltration in the extracellular matrix of the leaflets and chordae tendineae, causing regurgitation of blood into the atria. The resulting decrease in cardiac output activates neurohormonal mechanisms that cause adverse ventricular remodeling, often times accompanied of clinical signs and death. An international group of internal-medicine experts has proposed new guidelines for diagnosis and appropriate treatment of the disease. This paper consists of a critical review of that proposal, contextualizing it for the Colombian conditions, according to the experience of the author.
... pulmonar associado a dilatação do AE, elevação dorsal da traqueia e desvio vertical da silhueta cardíaca. O eletrocardiograma (ECG) é um método considerado inespecífico, sendo útil apenas para identificar distúrbios de condução decorrentes da sobrecarga nas câmaras, dessa forma, é importante para caracterizarmos o prognóstico do paciente (FOX et al., 1999;HÄGGSTRÖM et al., 2004;ABBOTT, 2016). Já a ecocardiografia é considerada o padrão-ouro para a DDVM, por permitir quantificar as dimensões das câmaras cardíacas, e assim, monitorar o paciente assintomático e avaliar quando for necessário introdução de terapia, fornecendo um prognóstico a curto e longo prazo (STROHM et al., 2018). ...
Article
Objectives: Echocardiography is used routinely to assess mitral regurgitation severity, but echocardiographic measures of mitral regurgitation in dogs have not been compared with other quantitative methods. The study aim was to compare echocardiographic measures of mitral regurgitation with cardiac magnetic resonance imaging-derived mitral regurgitant fraction in small-breed dogs. Methods: Dogs with myxomatous mitral valve disease scheduled for magnetic resonance imaging assessment of neurological disease were recruited. Correlations were tested between cardiac magnetic resonance imaging-derived mitral regurgitant fraction and the following echocardiographic measures: vena contracta/aortic diameter, transmitral E-wave velocity, amplitude of mitral prolapse/aortic diameter, diastolic left ventricular diameter:aortic diameter, left atrium:aortic diameter, mitral regurgitation jet area ratio and regurgitant fraction calculated using the proximal isovelocity surface area method. Results: Measurement of cardiac magnetic resonance imaging-derived mitral regurgitant fraction was attempted in 21 dogs. Twelve consecutive, complete studies were obtained and 10 dogs were included in the final analysis: vena contracta/aortic diameter (r = 0 · 89, p = 0 · 001) and E-wave velocity (r = 0 · 86, p = 0 · 001) had the strongest correlations with cardiac magnetic resonance imaging-derived mitral regurgitant fraction. E velocity had superior repeatability and could be measured in all dogs. The presence of multiple jets precluded vena contracta/aortic diameter measurement in one dog. Clinical significance: Measurement of cardiac magnetic resonance imaging-derived mitral regurgitant fraction is feasible but technically demanding. The echocardiographic measures that correlated most closely with cardiac magnetic resonance imaging-derived mitral regurgitant fraction were vena contracta/aortic diameter and E-wave velocity.
Chapter
This chapter provides an overview of cardiovascular physiology and pathophysiology; anesthetic agents; and cardiovascular patient evaluation, monitoring, and support during anesthesia to help the clinician prepare anesthetic plans for patients with mild to significant cardiovascular disease. It explains the relationship between mean arterial pressure (MAP) and cardiac output (CO). When considering the relationship of measured blood pressure (BP) to the definition of oxygen delivery, one must understand the components that derive a measured BP. The presence of underlying cardiac disease necessitates a more extensive patient evaluation compared to noncardiac patients. Specific comments regarding positive inotropes and vasopressors are included in the chapter for each type of heart disease. The chapter lists the general strategies intended to be specific to a patient presenting with heart failure. It presents appropriate information for the clinician to prepare an individually tailored anesthesia plan for each patient presenting with cardiac disease.
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Myxomatous mitral valve disease (MMVD) is the most common acquired cardiovascular disease in dogs and for this reason it is the subject of many researches. MMVD has a long asymptomatic phase and in many patients does not progress to heart failure. Despite being extensively studied, the pathogenesis of the disease is not completely understood. Recently, surgical valvular repair or mitral valve replacement have been demonstrated beingfeasible in dog and preliminary results have been encouraging. Realtime-echocardiography has been recently introduces in veterinary medicine and preliminary data suggest it can represent a useful tool for studying mitral morphology and function and it might be crucial for surgical treatment.
Article
The aim of this study was to apply a modified Kay–Reed (MKR) method, in which modified horizontal mattress sutures are placed in the mitral annulus without involvement of the middle scallops of the septal and mural leaflets in dogs, and to estimate its effect on left atrial pressure. Four normal laboratory beagles underwent the MKR procedure. The peak velocity and pressure halftime (PHT) of the E-wave and mean pulmonary capillary wedge pressure (PCWP) were measured to estimate left atrial pressure before and 1 month after surgery. The peak velocity of the E-wave significantly increased (p < 0.01), but the PHT of the E-wave was not prolonged 1 month after surgery (p = 0.110). The mean PCWP did not change (p = 0.200), and was within the reference range 1 month after surgery. Our MKR method is an alternative approach to mitral annuloplasty; it is easier to perform compared with traditional circumferential mitral annuloplasty and does not affect the PCWP, although the echocardiographic parameters are changed. However, further studies are needed in order to apply the MKR method to clinical cases such as those assessing the usefulness of the MKR method in small-sized dogs and its long-term durability.
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Impact of Environmental Tobacco Smoke have been revealed by research conducted on children, adolescents, adults and pets. Studies on the effects of environmental tobacco smoke is based to three different methods. Experimental studies with application of cigarette smoke as inhalation at certain times to the test animals, studies of cotinine and nicotine levels are measured by hair, urine, nail or biopsy materials taken from subjects and survey based studies. In the study, seventy-eight dogs who were brought to the Istanbul University, Faculty of Veterinary Medicine, Training and Research Hospital, Internal Medicine Department Clinic for examination by pet owners and the questionnaires were distributed to pet owners as randomized and the forms were used as material. With the questionnaire, frequency of daily cigarette consumption of pet owners at home and how long the house is ventilated after the consumption of cigarette were evaluated as correlation of diseases and effects of environmental tobacco smoke. Chi-squared (X2 ) test was used for analysis and disease analysis was made by frequency distribution, according to smoking or not. According to the results, it was found that dogs exposed to environmental tobacco smoke had the most frequent cardiologic and dermatological diseases. It was found that there was a significant correlation between the increasing cigarette consumption with the cardiological and dermatological diseases (p<0.001, p<0.05 respectively). While the increase of the ventilation period is expected to decrease the occurrence of diseases, contrarily significant data was obtained between the prolongation of the ventilation period and increased incidence of cardiologic and dermatological diseases (p<0.001, p<0.05 respectively). As conclusion that cigarette consumption may have an impact on the appearance of cardiological and dermatological diseases in dogs, increased cigarette consumption may increase the likelihood of these diseases, and ventilating the smoking environment may not reduce exposure.
Article
Heart disease can occur at any stage, either as a result of a congenital defect, such as a stenosis of one of the valves, or with degeneration over time. The two most common acquired diseases in dogs are mitral valve disease (MVD) and dilated cardiomyopathy (DCM). MVD can take years to develop from the first time it is diagnosed, whereas some cases can present with congestive heart failure (CHF) and need emergency treatment. DCM can have a long asymptomatic period eventually leading to CHF, if not preempted by sudden death. This article will discuss MVD and DCM, focussing on aetiology of both diseases, the diagnostic tests required and subsequent management aims.
Article
The aim of this study was to determine the histopathological changes of leaflets compatible with canine chronic valvular heart disease (VHD) in asymptomatic dogs. The samples were obtained from 38 hearts of canines from the Holding and Adoption Pet Center of Bogotá, Colombia, submitted to euthanasia as part of the district canine population control to prevent rabies. Animals were 57.9% males, 42.1% females, mainly mixed breed (n= 21), Poodle (n= 15), Cocker Spaniel (n = 1) and Schnauzer (n= 1). Weight was 7.34 ± 2.44 kg (3-13 kg) and the average age determined by dental evaluation was 7 ± 3 years (2-15 years). The histopathology interpretation was based on the Kogure classification. It was found using hematoxylin-eosin stain that 65.8% of the septal mitral leaflets and 68.4% of the lateral leaflets presented changes compatible with VHD, as well as the 55.3% of the septal leaflets of tricuspid valve and 84.2% of the lateral leaflets. With the alcian blue coloration, indicated to evaluate connective tissue, it was found that 76.3% of the septal leaflets of mitral valve and 76.3% of the lateral leaflets presented changes compatible with VHD. In the same way, when the tricuspid valve was evaluated, it was found that 68.4% of septal leaflets and 65.8% of lateral leaflets presented these changes. This demonstrates that lesions of the valvular apparatus begin before the appearance of murmur, the most frequent sign for this disease. The need of preventive medicine programs to reduce the morbility risk and mortality of this disease, related to ventricular remodeling as consequence of early neurohormonal activation, is emphasized.
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En caninos, la enfermedad valvular degenerativa o endocardiosis es la patología cardiovascular con mayor prevalencia. Se caracteriza por regurgitación de la sangre hacia las aurículas, con disminución del gasto cardiaco, lo que lleva a sobrecarga de volumen con hipertrofia excéntrica e insuficiencia cardiaca congestiva. Este reporte tiene como objetivo describir los hallazgos clínicos y de necropsia de un canino, sugestivos de una endocardiosis valvular. El paciente ingresó por consulta externa a la Clínica Veterinaria Carlos Martínez Hoyos, de la Universidad de Nariño (Pasto, Colombia). Su propietario lo reportó enfermo desde hacía dos meses, con signos de enfermedad respiratoria, pérdida de peso y decaimiento. En el examen clínico se encontraron membranas mucosas muy pálidas, disnea inspiratoria, estertores, desdoblamiento de S2, soplo de regurgitación mesosistólico grado 4 y dilatación abdominal con signo de choque de onda positivo. En la necropsia se evidenció abundante cantidad de material de aspecto acuoso traslúcido en cavidad abdominal, torácica y pericárdica, corazón severamente aumentado de tamaño, redondeado, con engrosamiento de válvulas atrioventriculares, hígado con moderada disminución de tamaño y evidencia de lobulillación, riñones severamente disminuidos de tamaño y pálidos de superficie irregular con presencia de múltiples áreas quísticas en región corticomedular. Se tomaron muestras de estos tejidos y se fijaron en formol bufferado al 10 %, para después ser procesadas para análisis histopatólogico en el Laboratorio de Patología de la Universidad de Nariño, mediante la técnica de hematoxilina y eosina de rutina. De esta manera se diagnostica como enfermedad valvular degenerativa.
Article
Chronic degenerative mitral valve disease (CDVD) represents the most common acquired cardiovascular disease in the dog. Although the disease has been described for more than 40 years, many physiopathologic and epidemiologic aspects need still to be clarified. This review summarizes the most up dated knowledge on the physiopathology, epidemiology and therapy of CDVD in dogs.
Article
Objectives: To determine the prevalence of mitral valve regurgitation (MR) in asymptomatic Swedish Norfolk terriers. Animals: Seventy-nine privately owned Norfolk terriers. Materials and methods: A prospective observational study was conducted where dogs were recruited via the Swedish Norfolk terrier club. All dogs were examined using the same protocol including physical examination and Doppler echocardiography. Results: Fifteen dogs (19%) had a murmur at the time of the examination. A total of 35 dogs (44%) had MR, including 23 dogs (29%) with both MR and tricuspid valve regurgitation and 12 dogs (15%) with MR only, identified on Doppler echocardiography. In addition, 7 dogs (9%) had tricuspid valve regurgitation only. The prevalence of MR increased with increasing age (p < 0.0001). Conclusions: Mitral valve regurgitation is common in asymptomatic Norfolk terriers with and without murmurs and the prevalence increases with age. The impact of MR in this breed on survival remains to be elucidated by a longitudinal study.
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Degenerative valvular disease or endocardiosis is the most common cardiovascular pathology in dogs. It is characterized by regurgitation of blood into the atria with decreased cardiac output, leading to volume overload with eccentric hypertrophy and congestive heart failure. This report describes the clinical and autopsy findings of a dog, suggestive of valvular endocardiosis. The patient was admitted to the outpatient Veterinary Clinic "Carlos Martínez Hoyos" at the University of Nariño (Pasto, Colombia). His owner said the dog was sick for two months, with signs of respiratory disease, weight loss, and decay. Clinical examination showed very pale mucous membranes, inspiratory dyspnea, rale, split S2, grade 4 mid-systolic murmur of regurgitation, and abdominal dilatation with sign of positive shock wave. Necropsy evidenced plenty of translucent watery material in the abdominal, chest and pericardium cavity, severely enlarged and rounded heart with thickened atrioventricular valves, moderate reduction in liver size and signs of lobulation, severely diminished and pale kidneys with irregular surface showing the presence of multiple cystic areas in corticomedullary region. Samples were taken from these tissues and fixed in 10% buffered formalin to be processed for histopathological analysis at the Laboratory of Pathology at the University of Nariño, using hematoxylin and eosin stain. This way, degenerative valvular disease was diagnosed.
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โรคลิ้นหัวใจไมทรัลเสื่อมเป็นโรคหัวใจภายหลังกาเนิดที่พบได้บ่อยในสุนัขโตเต็มวัยพันธุ์ขนาดเล็กถึงกลาง พบการเพิ่มขึ้นของทรานสฟอร์มมิ่งโกรทแฟกเตอร์เบต้า 1 ในลิ้นหัวใจของสุนัขที่เป็นโรคลิ้นหัวใจไมทรัลเสื่อม อย่างไรก็ตามยังไม่มีการประเมินพลาสมาทรานสฟอร์มมิ่งโกรทแฟกเตอร์เบต้า 1 มาก่อน วัตถุประสงค์ของการศึกษานี้เพื่อเปรียบเทียบความเข้มข้นของพลาสมาทรานสฟอร์มมิ่งโกรทแฟกเตอร์เบต้า 1 ในสุนัขปกติและสุนัขที่เป็นโรคลิ้นหัวใจไมทรัลเสื่อมด้วยวิธีอีไลซ่า การวัดนี้อาจช่วยในการแยกสุนัขที่เป็นโรคลิ้นหัวใจไมทรัลเสื่อมจากสุนัขสุขภาพดีได้ วิธีทดสอบแมนวิทนี่ถูกใช้เพื่อการเปรียบเทียบพลาสมาทรานสฟอร์มมิ่งโกรทแฟกเตอร์ เบต้า 1 ระหว่างสองกลุ่ม p-value น้อยกว่า 0.05 แสดงถึงนัยสาคัญทางสถิติ ผลการศึกษาแสดงความไม่แตกต่างทางสถิติ (p=0.574) ระหว่างค่ากลางของพลาสมาทรานสฟอร์มมิ่งโกรทแฟกเตอร์ เบต้า 1 ในสุนัขปกติ 22 ตัว (1.14, 0.94-1.33 นาโนกรัม/มิลลิลิตร) และสุนัขที่เป็นโรคลิ้นหัวใจไมทรัลเสื่อม 27 ตัว (1.21, 0.92-1.32 นาโนกรัม/มิลลิลิตร) โดยสรุปความเข้มข้นของพลาสมาทราสฟอร์มมิ่งโกรทแฟกเตอร์ เบต้า 1 น้อยมากในกระแสเลือด จึงไม่เหมาะสมที่จะเป็นตัวชี้วัดทางชีวภาพในการวินิจฉัยโรคลิ้นหัวใจไมทรัลเสื่อม.
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RESUMO A degeneração mixomatosa valvar mitral (DMVM) costuma ser diagnosticada pelo ecocardiograma, porém o eletrocardiograma (ECG) pode sugerir alterações específicas e auxiliar no diagnóstico e no tratamento. A deflexão intrinsecóide (DI) é uma medida simples do ECG, que representa o início da despolarização ventricular e pode indicar a presença de sobrecargas e hipertrofia no ventrículo esquerdo. O objetivo deste trabalho é comparar dados prévios sobre condição clínica e ecocardiograma de cães com endocardiose de mitral e o valor da deflexão intrinsecóide do ECG, para buscar uma relação de concordância. Foram selecionados os arquivos de 45 cães anteriormente atendidos na rotina clínica do HV-UPFR. A estatística mostrou diferença relevante nos grupos B1, B2 e C nas derivações D2, D3, aVF, rV, V2 e V4 (P<0,05), o que permitiu classificá-los de acordo com o tamanho da DI, e esse resultado correspondeu à classificação do consenso de endocardiose de mitral em cães nesses estágios. Concluiu-se que há um aumento gradativo no valor da DI à medida que a DMVM avança, principalmente nos estágios B1, B2 e C, associado à sobrecarga e à hipertrofia ventricular esquerda, portanto esse parâmetro pode ser usado na classificação da doença.
Chapter
This chapter provides an overview of cardiovascular physiology and pathophysiology, anesthetic agents, and cardiovascular patient evaluation, monitoring, and support during anesthesia to help the clinician prepare anesthetic plans for patients with mild to significant cardiovascular disease. Patients with cardiac disease should have some combination of preanesthetic electrocardiography, blood pressure (BP), thoracic radiographs, and echocardiogram depending on the type of cardiac disease. Systemic sedation that is appropriate for the patient's temperament and underlying disease in combination with locoregional analgesia may be sufficient for surgical analgesia in some cases. One major goal of adjunctive techniques or interventions is to increase cardiovascular stability and maximize CO and BP. Inotropes and vasopressors are drugs aimed at improving BP and perfusion by taking advantage of sympathetic nervous system receptor targets. The causes of heart failure or congestive heart failure are numerous and can be the result of a wide variety of cardiac diseases.
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The general aim of this thesis was to evaluate two different imaging techniques used to evaluate the heart of dogs with mitral regurgitation, one for measurements of left atrial size and one for general cardiac size and to compare cardiopulmonary imaging with plasma levels of natriuretic peptides. A more specific aim was to study the variability in objective measurements of left atrial and cardiac size and subjective evaluation of general cardiomegaly, left atrial enlargement and radiologic signs of congestive heart failure among groups of observers with varying experience in thoracic radiology. The experience levels included were; experienced radiologists, experienced small animal clinicians, trainees for a small animal specialist degree and veterinary students. General heart enlargement can be monitored by objective measurements but there is no way to objectively estimate left atrial size on radiographs. An established index method for measurements of left atrial size on M-mode echocardiogram was compared to an index that uses the two-dimensional (2-D) image for dimensional measurements. It was shown that the 2-D index can be used as a good predictor of left atrial size. The 2-D index had a greater sensitivity for left atrial enlargement compared to the M-mode index. Plasma levels of natriuretic peptides (ANP, NT-proANP and BNP) were studied as endogenous markers for increase in left atrial and ventricular size and left ventricular dysfunction. The plasma levels of the studied peptides did not increase in any significant way until there was radiologic and echocardiographic evidence of cardiac enlargement. However, the peptides were shown to be efficient in separating compensated from decompensated heart failure. In the objective measurement of heart size the interobserver variation of the vertebral heart size method had a mean variation among the 16 observers of around 1.0 VHS units. No difference in mean VHS values was found among the four groups of observers. The subjective evaluation had a large discrepancy amongst both the observers and between the observers and the gold standard. In general the observers overdiagnosed signs of congestive heart failure and underdiagnosed left atrial and general heart enlargement. Accuracy in the subjective interpretation of general cardiomegaly, left atrial enlargement and radiologic signs of congestive heart failure was not in any conclusive way affected by observer experience. Objective measurements of cardiac size were independent of observer experience but dependent on individual observers´ selection of reference points for measurements.
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Systolic myocardial function was assessed in 16 dogs with severe congestive heart failure due to chronic mitral valve fibrosis. End-systolic diameters were measured on echocardiograms and end-systolic volume indices were calculated. Thirteen of the 16 dogs (81%) had normal or only mildly abnormal myocardial function. These data suggested that myocardial failure is not a prominent factor contributing to signs of heart failure in dogs with mitral regurgitation. Because of these data, the routine use of digitalis glycosides to increase cardiac contractility is seriously questioned in dogs with heart failure secondary to chronic mitral regurgitation.
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Clinical studies have shown that Cavalier King Charles Spaniels (CKCS) have a high prevalence of mitral valvular insufficiency (MVI). Echocardiography has the potential to disclose early valvular changes, and the present prospective study was designed to investigate the occurrence of mitral valve prolapse (MVP) in young CKCS without heart murmurs, and to correlate the degree of MVP with the clinical status of the dogs by including CKCS with MVI as well. The study was based on blinded evaluations of echocardiographic recordings of mitral valves from 34 CKCS and 30 control dogs. Thirteen (87%) of 15 three-year-old CKCS without heart murmurs had MVP (2 total and 11 partial), as compared with 1 (7%) of 15 three-year-old normal Beagle dogs (P < 0.0001), and none of 15 three-year-old normal Medium Size Poodles (P < 0.0001). Of 19 CKCS with MVI, MVP was found in 84% of the entire group and in 100% of dogs with pulmonary congestion or edema. The occurrence of total MVP tended to be higher in the group with MVI (47%, 9/19), when compared with the younger CKCS without heart murmurs (13%, 2/15, P = 0.06). MVP was positively associated with excessive heart rate variability (P = 0.003). The radius of curvature of the anterior mitral valve leaflet in systole was significantly reduced in dogs with MVP when compared with those without (P < 0.0001). In conclusion, this study shows that CKCS at an early age have a high occurrence of MVP. This suggests: 1) A genetic predisposition of CKCS to MVP; and 2) That MVP is a pathogenetic factor in the development of mitral valvular insufficiency. Follow up studies may add further support to these proposals, and clarify whether echocardiography may be an aid in selecting CKCS for future breeding.
Article
A case of type 3 Ehlers-Danlos syndrome with associated mitral valve prolapse, right bundle-branch block, and left anterior fascicular block was studied, including His bundle electrocardiography and echocardiography. Mitral valve prolapse and HV prolongation were reported. The present study suggests that the basic underlying collagen defect in this syndrome is responsible for these findings, and that the association may be more widespread in the syndrome than currently acknowledged. The possibility also is considered that the connective tissue abnormalities of Ehlers-Danlos syndrome involving the heart may be the cause of some cases of idiopathic conduction system disease or valvular insufficiency. (Arch Intern Med 137:1227-1231, 1977)
Article
Time for primary review 31 days. Mitral valve prolapse (MVP), i.e. abnormal systolic protrusion of mitral valve leaflets into the left atrium, is a common cause of severe mitral regurgitation (MR) requiring operation in people living in industrialized nations [1,2]. MVP has been reported to have many causes but in the majority of cases it is a primary condition (called primary MVP in this paper) characterized by a progressive myxomatous degeneration of the mitral valve leaflets and chordae tendineae [1–3]. The disease typically emerges in adolescence but complications such as severe MR usually do not occur until middleage or senescence [1–3]. An animal model with a shorter course of disease could be useful in several ways, for instance, by making it feasible to evaluate the effects of different drugs on disease progression. Despite this, no animal model of primary MVP has been described so far. From pathological studies, it has long been known that most dogs develop myxomatous mitral valve disease with age and that this disease is very similar macroscopically as well as microscopically to primary MVP in humans [4,5]. Traditionally, however, the canine disease has been given names other than MVP, including endocardiosis and chronic valvular disease. Recently, a number of studies, including many based on well-defined echocardiographic criteria for the diagnosis of MVP, have increased our understanding of this disease in the dog. The purpose of this article is to compare the knowledge which has been accumulated about myxomatous mitral valve disease/MVP in the dog with knowledge of primary MVP in humans. Pathologically, primary MVP in humans is very similar to canine myxomatous mitral valve disease [4,5]. In both species, the principal macroscopic findings are enlarged, thickened leaflets, interchordal hooding and elongated chordae tendineae (Fig. 1A, B) [4–9]. In addition, affected … * Corresponding author. Tel.: +45-35-282-526; fax: +45-35-282-525 hdp{at}kvl.dk
Article
The present study tested the hypothesis that cardiac mast cells and chymase are associated with matrix metalloproteinase (MMP) activation and extracellular matrix (ECM) degradation in the evolution of left ventricular (LV) chamber remodeling secondary to experimental mitral regurgitation (MR) in dogs. LV mast cell density, chymase activity, and angiotensin II (ANG II) levels were significantly increased 2 and 4 weeks post-MR, while an increase in angiotensin-converting enzyme (ACE) activity was not seen prior to the chronic 24 week stage. As early as 2 and 4 weeks, there was a significant decrease in interstitial myocardial collagen content that was associated with an increase in LV end-diastolic diameter (LVEDD) but a normal LVEDD/wall thickness ratio. While mast cell density decreased to normal at 24 weeks, both chymase and MMP-2 activity remained increased throughout the entire 24-week period post-MR. By 24 weeks a transition to an adverse pattern of LV remodeling characterized by a 2-fold increase in the LVEDD/wall thickness ratio had occurred. Thus, this study supports the hypothesis that mast cells and chymase are important modulators of MMP activity and ECM degradation, contributing to adverse LV remodeling in chronic volume overload secondary to MR.
Article
A computer simulation program was used to examine interacting effects of genetic drift, mutation, immigration from outside populations, directional and balancing selection, and population subdivision on the loss of genetic variability from small, managed populations. Stochastic ewnts were simulated with a pseudo‐random number generator, and the genetic variation (expected heterozygosity) witbin and between populations was monitored in 25 populations for 100 generations. Genetic drift was the overriding factor controling the loss of genetic variation Mutation has no noticeable effect on populations of the size typically managed in zoos and nature preserves Immigration from a large source population can strikingly slow, halt, or even reverse the loss of genetic variation, even with only one or a few migrants per generation. Unless selection is stronger than commonly observed in natural populations, it is inefficient in countering drift when population sizes are on the order of 100 or fewer. Subdivided populations rapidly lose variability from within each sub‐population but retain variation across the subpopulations better than does a panmictic population. These results suggest that population managers should be concerned with the variation‐depleting effects of genetic drift, perhaps almost to the exclusion of consideration of selection and mutation Drift can be countered by the introduction of vety occasional immigrants or, less effectively, by division of the managed population into smaller breeding groups that interchange enough migrants to prevent unacceptably deleterious inbreeding within each subpopulation
Article
In this study, the observer variation and the influence of observer experience in diagnosing mitral valve prolapse in dogs was assessed by having three observers with different degrees of echocardiographic experience (10 years, 4 years, and no prior experience) analyze 303 mitral valve video recordings from 253 dogs, both with and without mitral regurgitation. To assess intraobserver variation, 16 recordings were analyzed twice, and 34 dogs were scanned twice at intervals of a few days. By consensus, 90 dogs had no mitral valve prolapse, 130 had mild and 33 had severe mitral valve prolapse. Intraobserver repeatabilities ranged from 88% to 100% and interobserver repeatabilities from 70% to 78%. In 79% to 94% of the dogs that were scanned twice, the observers diagnosed both recordings identically. All repeatabilities were reduced by approximately 10% when mitral valve prolapse was graded into mild and severe. The three observers differed significantly in diagnosing mitral valve prolapse when compared with each other in pairs (all p-values < 0.01). The unexperienced observer had the highest and most unsystematic occurrence of false diagnoses. It is possible that the interobserver repeatabilities would have been lower had each sonographer obtained his own echocardiograms. We conclude, that mitral valve prolapse in dogs can be diagnosed using two-dimensional echocardiography with the same degree of observer variation as reported in human studies, and that education and training of staff is mandatory to ensure proper ultrasonographic evaluation.
Article
Sixty-five dogs are reviewed with histopathologically confirmed intramural arteriosclerosis. Clinical data (clinical signs, electrocardiographic findings and ultrasound parameters) on these animals were collected from nine small animal clinics in Sweden: 16 dogs had died suddenly, with few or no previous clinical signs; 13 dogs died or were euthanased during or shortly after general anaesthesia or sedation; 30 dogs developed acute (14) or chronic (16) congestive heart failure; and six dogs died or were euthanased for causes unrelated to cardiac disease. Electrocardiography of 23 of the dogs revealed several types of arrhythmias, with atrial fibrillation and sinus tachycardia being most commonly detected. Ultrasonographic examinations of 24 dogs found a relatively high number (19) with decreased indices of contractility. Dogs that had died suddenly and in relation to general anaesthesia or sedation had a higher incidence (25 of 29) of purely arteriosclerotic changes in the myocardial vessels, whereas just over half the dogs with congestive heart failure (16 of 30) had other concomitant heart lesions (in most cases endocardiosis). The incidence of myocardial infarcts was high (51 of 65 cases). It is postulated that arteriosclerosis in the dog may be an important reason for sudden death and death during general anaesthesia. Coronary arterial disease should also be a consideration in the clinical evaluation of dilated cardiomyopathy and may contribute to the decreased myocardial contractility when it is present in dogs with mitral regurgitation.
Article
One hundred ninety consecutive Dachshunds >2 years of age, including 18 families consisting of both parents and 4 or more offspring, were examined clinically and echocardiographically to study the epidemiology and inheritance of mitral valve prolapse (MVP) and other signs of myxomatous mitral valve disease in the dog. From video-recorded echocardiograms, MVP severity, jet size (color Doppler), and leaflet thickness were assessed. With regard to murmur intensity and each of these 3 echocardiographic measurements, the inheritance and the influence of age, gender, coat type, body weight, degree of obesity, heart rate, and thorax dimensions were evaluated. MVP severity correlated positively with age (P < .0001) and heart rate (P= .002), negatively with thorax circumference (P= .0005), and was related to coat type (P= .006). MVP severity progressed faster in males than in females (P= .0002). The other measures of disease severity (jet size, leaflet thickness, and murmur intensity) also correlated positively with age (all P < .0001). When compared in pairs, all 4 measures of disease severity correlated significantly with one other. Pedigree analyses did not disclose agreement with simple Mendelian models, but high disease prevalence made interpretation difficult. Mean parental MVP severity correlated significantly with MVP severity in the offspring (P= .03). The epidemiology of MVP in Dachshunds resembles that of MVP in humans, MVP severity correlates significantly with other measures of the degree of myxomatous mitral valve disease, and MVP is an inherited condition in Dachshunds. A polygenic mode of inheritance is suggested.
Article
The case records of 58 German Shepherds (GS group) affected by mitral valve prolapse (MVP) and/or mitral valve regurgitation (MR), and 49 dogs weighing < 15 kg (D group), affected by chronic valvular disease (CVD) were reviewed. The dogs of the GS group were presented more often without a detectable heart murmur (p < 0.01), and less frequently with a high intensity heart murmur (p < 0.01). Atrial fibrillation (AF) was more common in the GS group (p < 0.001). MVP associated with mitral valve thickening was more common in the D group (p < 0.001). Fractional shortening (FS) was lower (p < 0.0001) and end-systolic volume index (ESV-I) was increased (p < 0.0001) in the GS group, whereas end-diastolic volume index (EDV-I) did not differ between the 2 groups. Prevalence and severity of pulmonary hypertension were similar in the 2 groups. Dogs with mitral valve disease weighing more than 20 kg had a 5.8 higher chance of developing decreased FS, increased ESV-I, AF and ventricular arrhythmias. In the GS group, the decreased FS and increased ESV-I were not associated with the presence of AF or ventricular arrhythmias (p > 0.05). It appears that GS may be affected both by mitral valve prolapse and mitral insufficiency. It also appears that a comparatively large proportion of GS shows no major mitral valve thickening or MVP, but still presents with significant mitral regurgitation, possibly suggesting a different cause for the important incompetence observed in most cases.
Article
This study was performed to test the hypothesis that measurements of jet area by Doppler color flow imaging will correlate with the severity of mitral regurgitation. Although Doppler color flow imaging is widely used to assess the severity of mitral regurgitation (MR), an accurate and quantitative marker of MR by color flow mapping remains elusive. 61 dogs with mitral regurgitation were evaluated by complete color Doppler studies. There were 42 males and 19 females, ranging from 6 to 18 years old (mean 11.19 +/- 2.51). Results of regurgitant jet area were compared with regurgitant volume and fraction by pulsed Doppler subtraction of mitral and aortic flows. They were also compared with effective regurgitant orifice area. Regurgitant jet area correlated well with both Doppler regurgitant volume and effective regurgitant orifice area. There were significant differences in jet area between groups of dogs with different severity of clinical signs of congestive heart failure (p < .001). Our results demonstrate that careful color flow mapping of the regurgitant jet area provides a simple quantitative assessment of MR that correlates well with other quantitative Doppler techniques.
Article
Objective: To study the responses of atrial natriuretic peptide (ANP), N-terminal fragment of pro-atrial natriuretic peptide (NT-proANP) and brain natriuretic peptide (BNP) to varying severity of mitral regurgitation (MR) in dogs with myxomatous valve disease (MVD). Design: Case-control. DOGS: 103 Cavalier King Charles Spaniels, 27 normal individuals and 76 with varying degree of MR. Procedure: Dogs were evaluated by physical examination, collection of venous blood, thoracic radiography and echocardiography. NT-proANP, ANP and BNP were measured in plasma using radio immunoassay (RIA). Results: The mean concentrations of NT-proANP were 37.4 and 83.5 times higher than ANP and BNP, respectively. The mean ANP to BNP molar ratio was 2.6. Plasma concentrations of NT-proANP and ANP were slightly increased in asymptomatic dogs with increased cardiac dimensions; those with signs of decompensated heart failure (HF) had mean concentrations of NT-proANP and ANP 3 to 7 times higher than normal dogs. The BNP concentrations were increased only in dogs with decompensated HF and the levels were approximately twice as high in these dogs as in normal individuals. Univariate and multiple regression analysis showed that primarily left atrial and ventricular size influenced the plasma concentrations of all 3 peptides (increased with increasing measurement). Analyses of response operating characteristic (ROC) curves indicated that NT-proANP and ANP were more discriminating than BNP for either cardiomegaly of HF. Clinical implications: Natriuretic peptides, particularly NT-proANP and ANP, may be of benefit in the overall assessment of dogs with naturally occurring MR. Analysis of NT-proANP may be more useful than ANP owing to easier handling of the samples and less laborious assay.
Article
In the study of 1984 routine hospital necropsies the mitral valve was examined from the left atrium in the intact heart with a pressure head of water in the left ventricle. The valve was graded from grade O (normal) to grade 4: grade 1, expansion of a small part of one cusp only; grade 2, over one-third of the posterior cusp or one-half of the anterior cusp expanded, with intact chordae; grade 3, ruptured chordae; grade 4, chordal fusion to ventricular wall. The frequency of grade 2 to 4 floppy valves rose with age with an overall incidence of 3.9 per cent in men and 5.2 per cent in women. Grade 1 floppy valves have no clinical significance. Grade 2 floppy valves were found to be associated with auscultatory signs but often only contributed to cardiac failure or were coincidental findings. Grade 3 and 4 floppy valves were direct causes of death from bacterial endocarditis and/or severe mitral regurgitation. The surgical series of floppy valves showed that chordal rupture was the event which most commonly made operation necessary in middle age: in a minority this was caused by bacterial endocarditis. Dilatation of the annulus was an important contributory factor but can produce significant mitral regurgitation without chordal rupture, particularly in inherited connective tissue disorders such as the Marfan syndrome. Forensic necropsies confirm that sudden death occurs in patients with floppy valves. The majority have grade 3 or 4 floppy valves and presumably significant mitral regurgitation. A minority have minimal valve involvement and the mechanism of death is unexplained. The exact magnitude of the risk for any patient with a floppy valve of developing bacterial endocarditis, or chordal rupture leading to significant mitral regurgitation, or of dying suddenly, is not known but must be very low considering the frequency of the valve lesion. The essential pathology of the floppy mitral valve is weakening of the central fibrous core allowing cusp expansion and chordal elongation to occur. The weakness of the collagen is in part genetically determined, in part age related. Identical changes occur in the tricuspid valve, and in the aortic root, leading to aortic regurgitation. Similar pathological changes are well recognised in other mammals, particularly the aged dog.
Article
A case of type 3 Ehlers-Danlos syndrome with associated mitral valve prolapse, right bundle-branch block, and left anterior fascicular block was studied, including His bundle electrocardiography and echocardiography. Mitral valve prolapse and HV prolongation were reported. The present study suggests that the basic underlying collagen defect in this syndrome is responsible for these findings, and that the association may be more widespread in the syndrome than currently acknowledged. The possibility also is considered that the connective tissue abnormalities of Ehlers-Danlos syndrome involving the heart may be the cause of some cases of idiopathic conduction system disease or valvular insufficiency.
Article
A consecutive series of 1288 mitral valves surgically excised from 1981 through 1989 were studied macroscopically and histologically. The explanted valves were affected by: chronic rheumatic disease (1179, 91.5%), floppy mitral valve (84, 6.5%), bacterial endocarditis (19, 1.5%), and post-ischemic mitral incompetence (6, 0.5%). Among 1179 post-rheumatic cases, mixed mitral stenosis and incompetence was the most frequent malfunction (747, 58%). Isolated mitral incompetence was diagnosed in 72 (6.11%) cases only, and isolated stenosis in 360 cases. In 52 valves, excised because of chronic rheumatic disease, the histology showed unexpected signs of acute rheumatism of the leaflets and the papillary muscles. In these patients clinical symptoms and blood tests were negative for rheumatic disease. Mitral incompetence, possibly due to papillary muscle dysfunction, was the prevalent lesion (61.5%). A total of 181 patients (14.05%) with pure mitral incompetence underwent surgery. In 84 patients (46.4%), the floppy mitral valve was the most frequent cause of valve dysfunction, 72 (39.8%) had rheumatic disease, 19 (10.5%) infective endocarditis, and 6 (3.4%) ischemic heart disease. In the group with floppy mitral valve, males were more prevalent than females (51:33). The mean age of the 4 patients with Marfan's syndrome and non-Marfan patients was noticeably different (17 vs 49 yr). Moreover leaflet deformation, tendinous cord elongation and annulus dilatation were the most common causes of valve incompetence. Floppy mitral valve and infective endocarditis were the cause of cordal rupture in 43.5% of the cases. This was a severe complication which always required emergency surgery.
Article
The prevalence of chronic valvular disease was studied in 494 cavalier King Charles spaniels with a mean (+/- sd) age of 3.0 +/- 2.7 years. Cardiac murmurs were detected in 65 (13.2 per cent) of the dogs. Among 61 cavalier King Charles spaniels with a mean age of 6.4 +/- 2.8 years, cardiac murmurs were detected in 32 (52 per cent). In both groups of dogs the prevalence of cardiac murmurs was low among dogs younger than three years (1.9 per cent) but increased with age (P < 0.001). The estimated ages at which 50 per cent of the dogs had developed murmurs were 7.5 and 6.2 years, respectively. When 39 of the 61 dogs were re-examined three years later, cardiac murmurs were detected in 28 (72 per cent), and the intensities of the murmurs had generally increased (P < 0.05). Nine (28 per cent) of the dogs which had previously had murmurs had been euthanased for signs of congestive heart failure whereas none of the dogs which had been free of murmurs had died from congestive heart failure. Animal insurance statistics from 1982 to 1990 (1983 excluded) for dogs less than 10 years old showed that claims for veterinary care or death or euthanasia were five times more common in the cavalier King Charles spaniel than in dachshunds (P < 0.001) and eight times more common than the mean for all other insured breeds (P < 0.001).
Article
This study was designed to answer two questions. First, does the left ventricular contractile dysfunction resulting from mitral regurgitation (MR) reflect a primary defect in the cardiac muscle cell? Second, what is the basis for any change in cellular contractile function that might be observed? Left ventricular volume overload was produced in 10 dogs by catheter transection of mitral chordae tendineae. Three months later in these and in seven control dogs, left ventricular contractile function was characterized by the end-ejection stress-volume relation (EESVR). Investigators who were blinded to these results then characterized the contractile performance of cardiac muscle cells, or cardiocytes, from these same left ventricles in terms of the viscosity (graded external load)-velocity relation. Finally, the tissue and cellular components of these same left ventricles were analyzed morphometrically. Both the left ventricles from the MR group and their constituent cardiocytes showed marked contractile abnormalities. By matching ventricles with cells from the same MR dogs, ventricular EESVR was correlated with cardiocyte peak sarcomere shortening velocity (SSV). The correlation coefficient between EESVR and SSV was 0.63, but between a size-independent measure of active ventricular stiffness and SSV, it was 0.88. No change in left ventricular interstitial volume fraction was found in MR dogs, but both ventricular and cellular contractile dysfunction strongly correlated with a decreased volume fraction of cardiocyte myofibrils. Last, in an attempt to relate the degree of contractile dysfunction to the hypertrophic response, left ventricular mass in the MR dogs was correlated with both cellular and ventricular contractile indexes; no significant correlation was found. Three conclusions are warranted by these studies. First, chronic left ventricular volume overload from mitral regurgitation leads to contractile defects at both the ventricular and cellular levels, the extent of which correlates well in individual animals. Second, no quantitative interstitial change resulted from MR. Taken together, these two findings strongly suggest that the contractile defect is intrinsic to the cardiocyte. Third, while the contractile abnormality in MR remains undefined, the most basic defects appear to be a combination of myofibrillar loss with the failure of compensatory hypertrophy to occur in response to progressive decrements in cellular and ventricular function.
Article
Although the prevalence of billowing mitral leaflets and mitral valve prolapse ranges from 6 to 18% of the population1 and histologic studies have been reported on resected valves,2−5 we are aware of only 1 study on the microstructure of such valves.6 We have not found any studies of the surface microarchitecture of floppy mitral valves shown by scanning electron microscopy. Therefore, we undertook an evaluation of the surface microarchitecture by scanning electron microscopy in the hope of providing additional insight into the nature of the floppy mitral valve syndrome.
Mitral valve prolapse is a manifestation of a diffuse connective tissue disorder resulting from mesenchymal dysplasia, and it may have an increased association with orthognathic craniofacial deformities. Since craniofacial deformities also result from mesenchymal dysplasias, there may be a causal relationship between them and mitral valve prolapse. Mitral valve prolapse is reviewed briefly in relation to the embryologic development of the facial skeleton. A slightly increased incidence of mitral valve prolapse has been noted but not statistically studied by the authors in their orthognathic patient population. It is hypothesized that patients with mitral valve prolapse have a typical facies that can be cephalometrically measured and identified.
Article
Chronic valvular disease (valvular endocardiosis) is the most common cardiac abnormality of the dog. This paper demonstrates how this condition increases in frequency and severity with advancing age by means of a visual impression method for the gross examination of the heart valves. These lesions occur in descending order of frequency and severity in the left atrioventricular valve, the septal cusp of the right atrioventricular valve, the mural cusp of the same valve, the aortic valve and the pulmonary valve. The histopathological features of these lesions are outlined.Résumé. La maladie chronique valvulaire (endocardiose valvulaire) est l'anomalie la plu commune chez le chien. Cette étude démontre comment la fréquence et la sévérité de cett condition s'accroissent avec l'âge par moyens de méthode d'impression visuelle pour l'examer en gros des valves du cœur. Ces lésions se produisent en order diminuant de fréquence et do sévérité dans la valve atrioventriculaire gauche, dans la cuspide septale de la valve atrioventri culaire droite, la cuspide murale de la même valve, la valve de l'aorte et la valve pulmonaire On souligne les caractéristiques histopathologiques de ces lésions.Zusammenfassung. Chronische valvuläre Erkrankung (valvuläre Endocardiosis) ist die gewöhnlichtste Herzabnormalität in Hunden. Diese Zeitschrift legt dar wir, mittels visuellem Eindrucksverfahrens für die allgemeine Untersuchung der Herzklappen, sich diese Kondition an Häufigkeit und Schwere mit zunehmendem Alter steigert. Diese Läsionen treten in abfallender Ordnung an Häufigkeit und Schwere in der linken Herzvorhof-Kammerklappe, der Cuspis septalis der rechten Herzvorhof-Kammerklappe, der Cuspis muralis von derselben Klappe, der aortischen Klappe und der pulmonalen Klappe. Die histopathologischen Merkmale von diesen Läsionen sind umrissen.
Article
One hundred and fifteen Chinese patients with mitral-valve prolapse were evaluated for skeletal abnormalities, to determine their prevalence and interrelation. Measurements of thoracic dimensions from radiographs differed significantly from the normal population. The commonest thoracic abnormality was the straight back, being present in 37.5% of the male and 26.9% of the female patients. Accurate quantitation of thoracic kyphosis was difficult. Either the ratio between antero-posterior and transverse thoracic diameters or a vertebral index characterised the straight back. Other abnormalities included scoliosis, sternal and rib deformities. The mean of metacarpal indices for the patients was also significantly higher than the normal mean. An abnormal metacarpal index was present in 20.9%. There was dissociation between peripheral and thoracic skeletal abnormalities. The diagnostic, aetiological and prognostic implications of associated skeletal abnormalities were discussed.
Article
Familial prevalence of mitral valve prolapse in a Chinese population was determined in 22 propositi of whom 10 had straight back (group A), three had abnormally high metacarpal index (group B), and nine had neither (group C). Of 71 (32 male and 39 female subjects) first degree relatives screened, mitral valve prolapse was found in 19 (seven male and 12 female subjects) (26.8%). The familial prevalence among groups A, B, and C was 20%, 30%, and 38.5%, respectively. Our study indicates that the familial occurrence of mitral valve prolapse does not depend on its association with the straight back syndrome.
Article
Thirty-two consecutive patients with keratoconus were screened for mitral valve prolapse by two dimensional echocardiography. The overall prevalence of 38% was found to be statistically different from a prevalence of 13% in a group of age- and sex-matched controls. Similarities in their pathophysiology indicate that an alteration in collagen metabolism may underlie both conditions.
Article
The association of mitral-valve prolapse with various inherited disorders of connective tissue, such as Marfan's syndrome and Ehlers-Danlos syndrome, has been well established. Although an association between pseudoxanthoma elasticum and mitral-valve prolapse has been briefly mentioned in the medical literature, the extent of the association has not been determined. To determine the prevalence of mitra-valve prolapse in this disorder, the authors performed echocardiography in 14 patients with pseudoxanthoma elasticum. Ten patients (71 per cent) had echocardiograms diagnostic of mitral-valve prolapse. No relation was found between the severity of skin lesions and the prevalence of mitral-valve prolapse. We conclude that since both conditions may have a common pathogenetic mechanism, it is not surprising that patients with pseudoxanthoma elasticum have a high prevalence of mitral-valve prolapse. It is recommended that these patients undergo careful auscultation and echocardiography to determine whether this valvular abnormality is present.
Article
Seventy-four patients with adolescent scoliosis underwent cardiac examination and M-mode echocardiography to detect the presence of mitral valve prolapse (MVP). Twenty-one (28%) had echocardiographic evidence of MVP, whereas 18 had auscultatory findings of a nonejection click or late systolic murmur. A subset of 41 patients had a family history of scoliosis and 37% had MVP. The incidence of MVP increased to 41% when a first degree relative, such as a sibling, parent, or offspring, had scoliosis. Thirty-six patients with scoliosis had additional thoracic hypokyphosis (straight back) and 13 (36%) had MVP. The incidence of MVP was 48% when the scoliosis and hypokyphosis were hereditary and increased to 53% when a familial history of skeletal abnormality was present. This study indicates a high incidence of MVP in patients with scoliosis and hypokyphosis, especially when the cardiac and skeletal systems may be affected by a generalized soft-tissue defect.
Article
This article has no abstract; the first 100 words appear below. To the Editor: Lebwohl and colleagues¹ performed M-mode echocardiography on 14 patients affected by pseudoxanthoma elasticum and found mitral-valve prolapse in 11 (71 per cent) (July 22 issue). We are conducting a multidisciplinary assessment of pseudoxanthoma elasticum. Preliminary results (unpublished) of cardiologic examinations in 28 unrelated patients do not confirm this high prevalence of mitral-valve prolapse. None of the 17 women or 11 men (mean age, 43.3 years; range, 13 to 71 years) hada systolic click, and only one had an apical systolic murmur. M-mode echocardiograms in 16 patients showed mitral-valve prolapse in 1. Two-dimensional echocardiograms in 26 patients . . .
Article
著者が収集した犬の心臓標本306例のなかから僧帽弁線維症の特徴を有する64例の心臓標本の僧帽弁について, 形態学的再検討と詳細な計測を行なった. 形態学的観察の結果, 弁はちょうど"ヨットの帆を張ったような変形"を示し, その病変の好発部位は前尖の後半分と後尖の後交連に隣接する弁のrough zoneであった. 弁および腱索を計測した結果, 弁ではそのrough zoneに過度な伸展が認められ, 腱索ではrough zoneに挿入する腱索に強い伸張が認められた. 一方, 交連部やcleftに挿入する腱索には伸張は認められなかった. 組織学的には, fibrosaにある膠原線維の粘液変性と弁表面の線維性増殖が認められた. そして, 病変の進行とともに多量の酸性粘液多糖類の沈着を認めた. 特に腱索の断裂を伴なった症例では腱索の膠原線維にも粘液変性が認められた. これらの所見から, 本症の本質的病変は膠原線維の変性であり, その結果, 弁の脆弱化が起こって, 特徴的な変化をもたらすものと考えた. これらの特徴はヒトにおける僧帽弁逸脱症候群のそれに酷似し, 比較心形態学上興味深い.
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