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Detection of innocent systolic murmurs by auscultation and their relation to hematologic and echocardiographic findings in clinically normal Whippets
Abstract
To determine murmur prevalence by auscultation of 105 apparently healthy Whippets without signs of cardiac disease, to determine the origin of these murmurs, and to evaluate the influence of sex, type of pedigree (ie, bred for showing or racing), and training on these murmurs.
Cross-sectional study.
105 client-owned Whippets.
All dogs were auscultated by the first author and underwent a complete physical and cardiological examination, together with a hematologic assessment. Several RBC variables and echocardiographic variables were compared between dogs with or without a murmur at the level of the aortic valve.
44 of 105 (41.9%) dogs had no murmur. A soft systolic murmur was present with point of maximal intensity at the level of the aortic valve in 50 (47.6%) dogs, at the level of the pulmonic valve in 8 (7.6%) dogs, and at the level of the mitral valve in 3 (2.9%) dogs. No significant differences were found in heart rate, rhythm, murmur presence, point of maximal intensity, and murmur grade between males and females, between dogs with race- and show-type pedigrees, or between dogs in training and not in training. Dogs with a murmur at the level of the aortic valve had a significantly higher aortic and pulmonic blood flow velocity and cardiac output, compared with dogs without a murmur.
Whippets have a high prevalence of soft systolic murmurs in the absence of any structural abnormalities, which fit the description of innocent murmurs. No influence of sex, pedigree type, or training was found on the occurrence of these murmurs in Whippets.
... Functional murmurs are typically loudest over the left heart base, and these systolic murmurs may be confused with the left apical systolic murmurs of mitral regurgitation (MR) [8]. Whippets are noted to be both at increased risk of MMVD [9] and to commonly have functional heart murmurs [10]. ...
... Screening programs for myxomatous mitral valve disease depend on reliable detection of true abnormality in a population at risk, and in the case of MMVD, abnormalities may be detected via auscultation, phonocardiographic examination, Doppler-echocardiographic examination, or some combination of these [4,10,12,13]. The prevalence of the disease in the population is a crucial part of the evaluation, allowing estimation of the PPV and NPV of a test as applied to a specific population, e.g. a specific breed of dog, or a specific age group. ...
... phonocardiography, Doppler echocardiography) may lead to overdiagnosis of MMVD when small, central MR jets are documented, even though the risk associated with these jets are unknown [12,14]. Higher intensity systolic heart murmurs are more likely to accurately detect MR echo [12,13], but accurate diagnosis via auscultation may be affected by presence of concurrent abnormalities [15], observer experience, environmental noise, circulatory dynamics, ease of auscultation [12], and in some types of dogs, the prevalence of ejection, or non-pathological murmurs [6,10]. The presence of non-pathological (functional) murmurs may lead to misdiagnosis of MR if auscultation alone is used for examination, or may obscure MR murmurs if the MR murmur is less intense than concurrent functional murmurs. ...
Objectives:
To assess the prevalence of functional ejection murmurs and murmurs of mitral regurgitation (MR) due to myxomatous mitral valve disease in healthy whippets; to assess the diagnostic value of auscultation to detect MR; and investigate the relationship between age and presence of echocardiographically documented MR (MRecho).
Animals:
A total of 200 healthy client-owned Whippets, recruited at national shows between 2005 and 2009 were involved in this study.
Methods:
Cross-sectional study. Dogs were examined by auscultation by one examiner and Doppler echocardiography by another, and results were compared. Prevalence of types of murmurs and MRecho were calculated and correlated to age. Accuracy of auscultation to predict MRecho was calculated.
Results:
Left-sided systolic heart murmurs were detected in 185/200 (93%) of dogs. Left apical systolic murmurs (Lapex) were detected in 57/200 (29%) and left basilar systolic murmurs (Lbase) in 128/200 of the dogs (64%). MRecho was present in 76/200 (38%) dogs. Prevalence MRecho was correlated with age (r = 0.96, p=0.0028). Mitral regurgitation detected by echocardiography was present in 12/78 (15%) of the dogs ≤ 2 years of age and in 59% of the dogs at 7-8 years old. Detection of Lapex predicted MRecho with sensitivity 65%, specificity 94%, positive predictive value 86%, and negative predictive value 81%; and accuracy improved when only dogs with more intense Lapex (grade ≥ 3/6) were considered.
Conclusions:
Systolic murmurs are common in North American Whippets and this breed exhibits a high prevalence of MRecho, which may be documented at a relatively early age. Whippets with non-clinical MRecho may not be identifiable by auscultation alone; echocardiographic examination may be required to exclude a diagnosis of MR. Louder heart murmurs allow more accurate localization in this population.
... 1,2 Although a cardiac murmur may be indicative of a congenital cardiac anomaly, a murmur may be present with no underlying heart disease, usually called an innocent murmur. [1][2][3][4][5][6][7][8][9][10] Deciding whether a murmur is innocent or the result of a cardiac anomaly could be challenging for general practitioners, as the diagnosis is based solely on auscultation. [11][12][13][14][15] This decision, however, is important, because a pup with a presumably pathologic murmur should ideally be referred to a veterinary cardiologist. ...
... A subcostal view was used to measure the peak blood flow velocity in the aorta using continuous wave Doppler mode to rule out aortic stenosis. 5 Blood flow velocities in the pulmonic artery and in the aorta below 2.0 m/s were considered to be physiologic, whereas a blood flow velocity above 2.0 m/s would be considered to be the cause of a murmur. ...
... In all puppies of the pilot study, the murmur was thought to be innocent based on earlier descriptions in the dog and human. [4][5][6][7][8][9][10] The major limitation of the pilot study is that no echocardiogram was performed on puppies with a murmur. Neither were the dogs later rechecked for spontaneous disappearance of the murmur. ...
Background
The aims of this study were to establish the prevalence of innocent cardiac murmurs in clinically healthy puppies, to investigate a possible correlation between the presence of an innocent murmur and hematocrit, and to describe the auscultation characteristics of innocent murmurs.HypothesisLower hematocrit contributes to the genesis of innocent murmurs.AnimalsFive hundred and eighty-four client-owned clinically healthy puppies, between 20 and 108 days old.Methods
Two cross-sectional surveys with a 1-year (n = 389 pups) pilot and a half-year (n = 195 pups) principal study periods. Cardiac auscultation was performed by a single, board-certified cardiologist. Hematocrit was measured with an automatized hematology analyzer. Echocardiography was performed only on puppies with a cardiac murmur in the principal study.ResultsIn the pilot study, 15% of the dogs had a murmur. Innocent murmur was diagnosed in 28% of the 195 dogs in the principal study. Innocent murmurs were systolic, mostly with a musical character and with a maximal intensity of 2 of 6, and mostly with the point of maximal intensity in the left cardiac base. The hematocrit was significantly lower in the group with a murmur compared to the group without (P = .023).Conclusions and Clinical ImportanceInnocent murmur was a common finding in puppies at the age when the first veterinary controls usually take place. Physiologic anemia contributes to the genesis of innocent murmurs in puppies. Rising hematocrit in growing puppies can explain the spontaneous disappearance of innocent murmurs with aging. Hematocrit did not differentiate innocent murmurs from abnormal murmurs.
... An innocent heart murmur is found on average in 28% of puppies under the age of 6 months, while in athletic dog breeds such as whippets, it has even higher percentages of up to 58% of puppies [11,12]. It is a systolic heart murmur characterized by a short duration, left PMI, mild degree (I-II/VI), clear character, sometimes defined as a "whistle" or "musical" sound. ...
The detection of a congenital heart defect at purchase is an important step in early detection from a clinical and legal standpoint. Indeed, some cardiac abnormalities may be corrected with surgery, and very often, treatment needs to be performed early before congestive heart failure or irreversible heart damage can occur. From a legal viewpoint, if the defect is revealed in a newly purchased puppy, the buyer may be required to return it and receive compensation. Puppies affected with congenital heart defects are likely to die prematurely, causing emotional suffering to the owner. Furthermore, by considering breed predisposition, early recognition allows breeders to avoid breeding from particular dogs with genetic defects and prevent the continuation of genetic defects in breeding lines. Given gaps in the literature about the recognition of murmurs in the puppy trade, the present article describes how to identify a heart murmur in a puppy during a pre-purchase examination and its significance from a clinical and legal viewpoint. In the canine population, the prevalence of cardiac defects ranges between 0.13 and 1.6%. Pulmonic stenosis is the most common defect found in puppies, followed by patent ductus arteriosus, subaortic stenosis, and ventricular septal defect. On the basis of the above considerations, the veterinarian should recognize and identify the murmur following a protocol for routine examination of puppies involved in trade.
... In the present study, 7% of healthy adult ASTs presented a soft left basilar murmur. The presence of non-pathological (functional) murmurs in healthy adult dogs has already been reported in other breeds such as Boxers and Whippets [2,27]. The possible incidence of functional murmurs in healthy ASTs should be taken into account during the physical examination for screening and/or clinical reasons. ...
This study reports the echocardiographic reference intervals in the American Staffordshire Terrier (AST). The echocardiographic variables obtained in 57 healthy adult AST were compared with published data from the general canine population and other breeds. In the AST, the left ventricular volumes were lower than values reported in Boxers and Dobermans (P<0.0001), but higher than in small breeds (P<0.0001). The left ventricular ejection fraction was higher than Boxers and Dobermans (P<0.0001), but lower than small breed dogs (P=0.027). The aortic peak velocity values were similar to Boxers (P=0.55) but higher than the general canine population (P<0.0001). The reference intervals presented in this study are clinically useful for an accurate echocardiographic interpretation and screening in the AST.
... The systolic blood pressure was significantly lower in the G1, but no hypotension (< 70 mmHg) or hypertension (> 150 mmHg) were observed in those animals despite the low values. A previous study observed hypertension in 12% of the dogs afflicted by CME, which was later found not to be a possible cause of the condition [31,32]. We believe that the lower blood pressure values in G1 than in G2, even though still within the reference values, are caused by the factors such as anemia, hypoalbuminemia, dehydration, possible cardiac hypocontractility and the release of inflammatory factors in the blood flow [33]. ...
Canine Monocytic Ehrlichiosis (CME) is a systemic disease prevalent in the entire world caused by the obligate intracellular bacteria Ehrlichia canis. The occurrence of myocarditis with a high prevalence of arrhythmias in dogs affected by this disease in the cytopenic phase has already been proven. This study aims to evaluate the concentrations of CK MB, cTnI and NT-proBNP in dogs affected by Ehrlichia canis in the chronic phase since the intense stimulation of the immune system can lead to myocarditis; to evaluate if the condition can lead to arrhythmic events and, if so, define their frequency and classification through conventional and ambulatory electrocardiogram tests (Holter method) for a period of 24 hours; to analyze heart rate variability in the time domain and whether the condition can lead to autonomic imbalance; and to determine the survival rate of affected dogs, identifying possible risk factors for mortality at this stage of the disease. For this purposes, we evaluated clinical, hematological and biochemical data, as well as the concentrations of cardiac biomarkers Creatine Kinase-MB (CK MB), Cardiac Troponin I (cTnI) and N-terminal pro-peptide natriuretic type B (NT-proBNP). We also analyzed conventional and ambulatory electrocardiography (24-hour Holter) and heart rate variability (HRV) in 20 dogs afflicted by cytopenic CME in the chronic phase of the disease (G1) and compared the results with a control group comprised of ten healthy dogs (G2). G1 was monitored during the treatment for 28 days, during which eight (8) of the 20 infected dogs died (40%). Anorexia, vomiting, fatigue, hypoalbuminemia, heart murmurs and increased concentrations of alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were common clinical signs. The mean concentrations of cTnI and CKMB were significant (0.24 ng / mL ± 0.5, 229 ± 205 IU / mL) in comparison to the control group (0.042 ± 0.07 ng / mL, 126 ± 46.12 IU / mL). No significant differences were observed between NT-proBNP concentrations in G1 (135.46 ± 29.7) and G2 (138.28 ± 19.77). Nine of the twenty dogs (45%) presented a high frequency of arrhythmias during 24-hour recording, ranging from first and second-degree atrioventricular block, ventricular and supraventricular ectopic events and sinus tachycardia. No sinus pause was observed. One dog had 120 episodes of unsustained ventricular tachycardia and two episodes of sustained ventricular tachycardia. The short-term and long-term HRV data, represented by SDNN (ms), SDANN (ms) and pnn50 (%) were also significant lower (83 ± 65, 56.05 ± 37.3 and 14.56 ± 20, respectively) in comparison to the healthy animals (268 ± 74.6, 168.3 ± 39.14 and 55.87 ± 12.8, respectively). These results suggest that cytopenic CME is characterized by an arrhythmogenic component and intense stimulation of the sympathetic autonomic nervous system in the heart, reflecting an imbalance in the activity of the ANS.
... Experienced cardiologists perform better than inexperienced in classifying degrees of murmurs as well as distinguishing regurgitant murmurs from ejection flow murmurs (Pedersen, Häggström et al. 1999). Ejection flow murmurs or mild regurgitant murmurs have been described in athletes (Mukerji, Alpert et al. 1989, Barrett, Ayub et al. 2012), racing dogs (Marin,, Bavegems, Duchateau et al. 2011) and cats (Nakamura, Rishniw et al. 2011), without apparent echocardiographic evidence of heart disease. Although innocent physiologic flow murmurs may be distinguished from regurgitant murmurs as low grade high frequency murmurs near the base of the heart (Pedersen, Häggström et al. 1999). ...
Myxomatous mitral valve disease causing mitral regurgitation (MR) is a common cause of heart failure in dogs. However, many aspects of pathophysiology affecting diagnostic measurements are poorly defined. The objective of this study was to add to the knowledge of different pathophysiological processes affecting measures used. Focus was put on plasma parameters, including N-terminal pro A-type natriuretic peptide (NT-proANP) and nitric oxide (NO), and first pass radionuclide angiocardiography to evaluate heart pump function and possible right sided heart enlargement associated with pulmonary hypertension. Echocardiography and thoracic radiographs were used as reference methods.
Results. In normal dogs both NT-proANP (P=0.002) and NO (P=0.01) increased with age. Plasma NT-proANP concentrations for dogs under 5.9 years of age were lower than for dogs older than 5.9 years (inter quartile range 190–270 pmol/l vs. 307–530, respectively), with no overlap between groups. This discrimination was not seen for NO. In healthy dogs heart rate normalized blood pulmonary transit time (nPTT) was 4.4±0.6, dogs with asymptomatic MR 6.3±1.6, and dogs with CHF 11.8±3.4 (P<0.001). The size of the right heart chambers increased only late in MR. Pulmonary blood volume (PBV) was associated with nPTT (R2=0.85, P<0.0001) but not with forward stroke volume. Increase in PBV appeared late in the phase before CHF. The hazard ratio for NT-proANP was 1.21 (per 100 pmol/l; P<0.0002). The median time to failure was 11 months for dogs with NT-proANP concentrations >1000 pmol/l and 54 months for dogs with concentrations ≤1000 pmol/l (P<0.0001). Dogs that developed CHF had a lower mean plasma level of NO than dogs not reaching CHF (mean 23 vs. 28 µmol/l (as nitrite), P=0.016). Increased heart rate (>130 beats/min, P<0.001) and heart murmur (3-6/6 vs. 1-2/6, P<0.001) increased risk.
Conclusions. Specific normal values for natriuretic peptides should be established for different age groups of dogs. Heart rate, murmur and NT-proANP can be used to predict risk of and time to heart failure in dogs with MR. Heart rate normalized PTT (nPTT) is a robust measure of heart pump function in MR. Both nPTT and pulmonary blood volume increase before onset of CHF. Apparent right-sided heart enlargement on radiographs is due to them being displaced by left heart chambers as they enlarge only in severe MR.
... " (treatment question). As heart murmurs can be present in young dogs with a variety of congenital heart diseases (Oliviera et al. 2011) and also in dogs without heart disease (Bavegems et al. 2011, Höglund et al. 2011), the answer is rarely a simple one. A good " rule of thumb " is that a low-intensity left basilar murmur in a puppy may be associated with a healthy heart and may disappear by adulthood. ...
Borzoi are large, relatively uncommon sighthounds anecdotally reported to suffer from sudden death. This multicenter retrospective cohort study aimed to describe the sample of Borzoi presenting to veterinary cardiologists for evaluation, with records searched from 14 centers across a study period of up to 20 years. The study sample was comprised of 152 client-owned Borzoi, with dogs most commonly presenting for pre-breed screening in 87/152 (52%), followed by evaluation of an arrhythmia in 28/152 (18%). Of the 131/152 (86%) dogs that had an echocardiogram performed, 85/131 (65%) were structurally normal, with 40/85 (47%) structurally normal dogs having trace or mild atrioventricular valve regurgitation. Tricuspid valve dysplasia was the most commonly diagnosed congenital cardiac disease (n = 6). Myxomatous mitral valve disease (n = 12) and dilated cardiomyopathy (n = 13) were diagnosed at similar frequencies, though 92% of valve disease cases were mild. Only 48/152 (32%) Borzoi had a diagnostic electrocardiogram (ECG) and/or a Holter monitor for arrhythmia screening. Despite this, ventricular arrhythmias were identified during the entirety of the available cardiac evaluation including diagnostic ECG, contemporaneous ECG monitoring during the echocardiogram, and/or Holter monitor in 25/131 (19%) dogs in which an echocardiographic diagnosis was available. Of these 25 Borzoi, 76% had minimal or no structural cardiac disease identified, and five had a family history of sudden death. A sudden death outcome was reported in 3/55 (5%) Borzoi with long-term outcome data available. In conclusion, Borzoi commonly have trace or mild atrioventricular valve insufficiencies, and may develop ventricular arrhythmias and dilated cardiomyopathy.
Introduction:
To report normal echocardiographic variables from a population of healthy Salukis in North America.
Animals:
The study included 83 healthy adult Salukis from North America with structurally normal hearts.
Methods:
All animals underwent a full physical examination and two-dimensional, M-mode, and Doppler echocardiography using the right parasternal and left apical views with the left ventricular volumes calculated using the Simpson's method of discs. Echocardiographic variables were compared among sex, body surface area, and body weight (BW) using linear regression. The 95% predictive intervals were calculated for both unadjusted and BW-adjusted data.
Results:
No relationship between sex and the echocardiographic variables was noted. Predictive intervals for echocardiographic variables are presented for 22 echocardiographic variables. Linear regression suggested that 16 of those variables were associated with BW. The 95% predictive intervals of echocardiographic variables adjusted for BW are reported.
Conclusions:
The data from this study provide breed-specific echocardiographic reference values for Salukis.
Background:
Sighthound breeds are known to have different cardiac sizes and dimensions from other breeds; therefore, breed-specific references are required to avoid misinterpretation of echocardiographic findings. End-diastolic volume (EDV) and end-systolic volume (ESV) reference intervals derived from Simpson's method of discs (SMOD) do not exist for Salukis or Whippets.
Objectives:
To establish EDV and ESV reference intervals for SMOD in Salukis and Whippets.
Animals:
110 Salukis and 119 Whippets.
Methods:
Reference intervals for SMOD with and without normalization to body surface area (BSA) were established using the right parasternal and left apical views in 93 healthy Salukis and 82 healthy Whippets. Volumes were compared between both echocardiographic views, genders, and racing and show pedigree dogs. The 90% reference intervals were calculated using the robust method.
Results:
Agreement between right-sided and left-sided echocardiographic views was good. Reference intervals indexed to body surface area (BSA) for Whippets were 59-109 mL/m² for end-diastolic volume index and 18-53 mL/m² for end-systolic volume index. Corresponding values for Salukis were 68-126 mL/m² for end-diastolic volume index and 27-64 mL/m² for end-systolic volume index. There were no indexed volume differences between male and female or racing and show pedigree dogs in both breeds. The non-normalized volumes significantly differed between genders.
Conclusions and clinical importance:
Whippets and Salukis had larger systolic and diastolic left ventricular volumes compared with other breeds. This study provided echocardiographic reference intervals for SMOD-derived left ventricular volumes for these athletic breeds.
A dog or a cat has an incidentally detected heart murmur if the murmur is an unexpected discovery during a veterinary consultation that was not initially focused on the cardiovascular system. This document presents approaches for managing dogs and cats that have incidentally-detected heart murmurs, with an emphasis on murmur characteristics, signalment profiling, and multifactorial decision-making to choose an optimal course for a given patient.
To date, epidemiological studies on degenerative mitral valve disease (DMVD) in dogs have largely reported referral caseloads or been limited to predisposed breeds. Analysis of primary-care data to identify factors associated with DMVD would help clinicians identify high-risk individuals and improve understanding.
To estimate the prevalence of and identify risk factors for DMVD in dogs attending primary-care veterinary practices in England.
Cases were identified within the electronic patient records of 111,967 dogs attending 93 practices. Four hundred and 5 dogs were diagnosed with DMVD (diagnosed cases) and a further 3,557 dogs had a heart murmur (HM) consistent with DMVD (possible cases).
Retrospective cross-sectional study design. Prevalence was adjusted for the sampling approach. Mixed effects logistic regression models identified factors associated with DMVD.
Prevalence estimates of diagnosed DMVD and HMs consistent with DMVD (both diagnosed and possible cases) were 0.36% (95% confidence interval [CI]: 0.29-0.45) and 3.54% (95% CI: 3.26-3.84) respectively. In the multivariable analysis, males had higher odds of diagnosed DMVD than did females (odds ratio [OR] 1.40, 95% CI: 1.12-1.74). Insured dogs had increased odds of DMVD compared with noninsured dogs (OR 3.56, 95% CI: 2.79-4.55) and dogs ≥20 kg had approximately half the odds of DMVD diagnosis compared with dogs <20 kg (OR 0.51, 95% CI: 0.36-0.74). Strong associations between a DMVD diagnosis and individual breeds and age were identified.
Degenerative mitral valve disease was a common disorder in practice-attending dogs. Knowledge of identified risk factors for DMVD could improve clinical diagnosis and direct future research.
Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
To determine the prevalence of physiological heart murmurs in healthy young adult dogs.
Healthy dogs aged between 1 and 5 years were enrolled prospectively. All participating dogs underwent physical examination, urinalysis, blood testing and blood pressure measurement. Cardiac auscultations were performed by three independent examiners. Dogs with heart murmurs underwent echocardiography, to exclude cardiovascular abnormalities.
Of 109 dogs evaluated, 95 completed the study. Heart murmurs were detected in 22 dogs. Interobserver agreement for murmur detection was moderate to fair (weighted kappa 0 · 29-0 · 56). On the basis of two different sets of echocardiographic criteria, physiological heart murmurs were diagnosed in 6 and 11 dogs, respectively, giving a prevalence of 6-12%. All physiological heart murmurs were systolic and low-grade (I-III/VI). Most were louder towards the left heart base and some radiated up to the thoracic inlet. The epidemiological features of dogs with physiological heart murmurs did not differ significantly from those of dogs without murmurs (P > 0 · 10).
This study shows that physiological heart murmurs may not be limited to growing dogs or specific breeds, as they were commonly encountered in this population of healthy young adult dogs.
© 2014 British Small Animal Veterinary Association.
Objectives:
The objectives of this study were to obtain standard echocardiographic measurements from healthy Border Collies and to compare these measurements to those previously reported for a general population of dogs.
Animals:
Standard echocardiographic data were obtained from twenty apparently healthy Border Collie dogs. These data (n = 20) were compared to data obtained from a general population of healthy dogs (n = 69).
Methods:
Border Collies were deemed healthy based on normal history, physical examination, complete blood count, serum biochemical profile, electrocardiogram, and blood pressure, with no evidence of congenital or acquired heart disease on echocardiographic examination. Standard two dimensional, M-mode, and Doppler echocardiographic measurements were obtained and normal ranges determined. The data were compared to data previously obtained at our hospital from a general population of normal dogs.
Results:
Two dimensional, M-mode, and Doppler reference ranges for healthy Border Collies are presented in tabular form. Comparison of the weight adjusted M-mode echocardiographic means from Border Collies to those from the general population of dogs showed Border Collies to have larger left ventricular systolic and diastolic dimensions, smaller interventricular septal thickness, and lower fractional shortening.
Conclusions:
There are differences in some echocardiographic parameters between healthy Border Collies and the general dog population, and the echocardiographic reference ranges provided in this study should be used as breed specific reference values for Border Collies.
The cardiovascular system adapts to exercise. With conditioning, the heart modifies its physiologic and morphologic structure. When those changes occur in athletes seeking clearance for sports participation, they comprise the athletic heart syndrome. With detraining, many of those modifications normalize, which is a diagnostic feature of the athletic heart syndrome. It is important for practitioners who care for athletes to be cognizant of those adaptations and to differentiate them from pathologic changes that may warrant restriction from sports participation or place the athlete at risk for sudden cardiac death.
The cardiac effects of endurance training were evaluated by cardiac auscultation and electrocardiographic examination of 48 heavily trained sled dogs (3,000-5,000 km of training), 18 lightly trained sled dogs (300-800 km of training), 19 untrained sled dogs, and 14 mongrel dogs. A grade I-II/VI early- to midsystolic cardiac murmur was auscultated with increasing frequency as training level increased. The QRS duration (66.1 +/- 7.4 ms) and QT interval (236 +/- 20 ms) were significantly (P < 0.05) longer in heavily trained sled dogs than in mongrel dogs (QRS, 60.6 +/- 4.6; QT, 219 +/- 11 ms). A long QT interval (> 250 ms) was observed in 8 (16.7%) heavily trained dogs but not in the other groups. A significant rightward shift in the mean electrical axis of ventricular depolarization in the frontal plane was observed in heavily trained sled dogs. The auscultatory and electrocardiographic findings in heavily trained sled dogs were remarkably similar to those reported in elite human endurance athletes, suggesting that endurance-trained sled dogs provide a naturally occurring model for the athletic heart syndrome.
Cardiological findings in athletes are often similar to those observed in clinical cases. Electrocardiographic and cardiac imaging abnormalities as well as physical findings may be the same in both of these groups. Bradycardia and rhythm disturbances are the most common abnormalities in athletes. Most athletes with abnormal electrocardiograms are asymptomatic and numerous investigators have failed to detect heart disease in association with such electrocardiograms. In contrast to cardiac dysfunction observed in clinical cases, enhanced or normal ventricular systolic and diastolic function have been reported in athletes. In endurance athletes, this is associated with very high values for maximal aerobic power (V̇O2max).
Absolute and body size-normalised cardiac dimensions in most athletes do not approach values from chronic disease states, and may not exceed echocardiographic normal limits. In addition, pathological and physiological enlargement appear to be biochemically and functionally different. Myosin ATPase enzyme expression and calcium metabolism are different in rats with pathologically or physiologically induced enlargement. The reported biochemical differences underlie systolic and diastolic dysfunction in pathological enlargement. Conversely, trained rodents and humans have demonstrated enhanced systolic and diastolic function. It is important to note that cardiac enlargement observed in athletes is the result of normal adaptation to physical conditioning and/or hereditary influences. Conversely, pathological changes result from disease processes which can lead in turn to reduced function, morbidity and mortality.
Since the mid 1970s echocardiography has been used to compare cardiac dimensions in male endurance- and resistance-trained athletes. A sport-specific profile of eccentric and concentric enlargement has been documented in endurance and resistance athletes, respectively. Subsequent studies of athletes have examined factors such as age, sex and degree of competitive success to determine their contribution to these sport-specific cardiac profiles. Unique athletic subgroups have also been analysed and have included ballet dancers, rowers, basketball players and triathletes. However, there is a paucity of data on cardiac dimensions in female athletes. Finally, physical conditioning studies have also examined echocardiographic dimensions before and after endurance and resistance training. Significant enlargement of internal dimensions, wall thickness or left ventricular mass have been reported but such increases are relatively small and by no means universal.
Several conflicting explanations for enlarged cardiac dimensions appear in the literature. Chronic volume and pressure haemodynamic overloading during physical conditioning has been proposed to explain eccentric and concentric cardiac enlargement in endurance- and resistance-trained athletes respectively. However, twin studies suggest that hereditary factors may be important determinants of cardiac dimensions and/or the degree of cardiac adaptability to physical conditioning.
Another body of research has suggested the possibility that endocrine effects related to normal growth and/or physical conditioning may stimulate cardiac enlargement. Thyroid hormone, catecholamines, growth hormone and testosterone can alter cardiac dimensions and their blood levels are elevated with exercise. However, their influence on myocardial structure in athletes has not yet been clarified. In this regard, blood testosterone levels increase transiently following acute exercise bouts in young men and may contribute to the process of skeletal muscle hypertrophy. Significant statistical associations have been reported between skeletal and cardiac muscularity. Therefore, a common influence of testosterone or other hormones on skeletal and cardiac muscle hypertrophy has been hypothesised and may account for hereditary and/or conditioning induced cardiac enlargement in athletes. Future investigations should reassess the role of haemodynamic stress and clarify the quantitative role of heredity and endocrine factors in determining cardiac dimensions. In this way a clearer indication may be deduced as to the mechanism(s) involved in the apparent moderate cardiac enlargement reported in athletes. Research should first describe the cardiac profile of a wide range of female athletes and then determine the cause of any potential gender-based differences in cardiac size and adaptation to exercise.
Objectives. The purpose of this study was to determine the frequency, clinical features and echocardiographic characteristics of increased intraventricular velocities (IIVs) in patients referred to the echocardiography laboratory for systolic murmur.Background. A subset of patients referred to the echocardiography laboratory for evaluation of a systolic murmur have IIVs in the absence of other recognized causes of systolic murmur.Methods. We prospectively studied echocardiograms from 108 consecutive patients referred for evaluation of a systolic murmur. Clinical data were obtained from patient examinations and medical records.Results. The sole explanation for systolic murmur was IIVs in 16.7% of referred patients. Compared with those without IIVs, patients with IIVs had a higher ejection fraction (EF) (58.7 ± 7.8% vs. 51.1 ± 12.5%, p < 0.001), percent fractional shortening (42.3 ± 9.7% vs. 31.0 ± 11.4%, p < 0.0001), left ventricular (LV) mass index (181 ± 70 vs. 152 ± 48 g/m2, p = 0.046) and prevalence of hypertension (73.3% vs. 51.7%, p = 0.043) and a lower prevalence of segmental wall motion abnormalities (2.2% vs. 39.3%, p < 0.001).Conclusions. Increased intraventricular velocities are a common cause of systolic murmur in this group of patients and should be included in the differential diagnosis of systolic murmurs in adults. The association of IIVs with LV hypertrophy should be a clinical consideration when these murmurs are identified.
Athletic training can cause morphological cardiac changes as part of physiological adaptation. When these changes result in abnormalities of physical examination, the electrocardiogram, chest radiography or echocardiographic findings the individual is said to have athlete’s heart syndrome. Many of these changes mimic significant cardiovascular disease, including myocardial ischaemia, hypertrophic cardiomyopathy (the most common cause of sudden cardiac death), dilated cardiomyopathy and pericarditis. Recognizing and distinguishing physiological changes from significant cardiovascular disease is extremely important in an emergency medicine setting. Inappropriate or withheld treatment can affect morbidity and mortality significantly; detection of genuine cardiovascular disease usually requires exclusion from athletic competition to reduce the risk of sudden death. A number of criteria and methods have been proposed to assist in the task of differentiating physiological from pathological changes. Three case reports of ultra-endurance athletes, which highlight these dilemmas, are presented. These patients had significant electrocardiogram changes, including marked ST segment elevation, T wave inversion and evidence of left ventricular hypertrophy. This paper discusses the morphological and clinical changes associated with athlete’s heart syndrome and the current criteria and methods available to help differentiate this from cardiovascular disease. In many emergency department situations, a clinical history and examination may be all that is required. More complex cases are best resolved by use of echocardiography. Emergency physicians need to be aware of this syndrome and the diagnostic difficulties they may face when managing such patients.
Background:
Cardiac murmurs associated with valvular regurgitation occur commonly in conditioned performance horses, but their association with athletic performance is unknown.
Hypothesis:
Cardiac valvular regurgitation has a negative association with race performance.
Animals:
Five hundred and twenty-six "race fit" Thoroughbred racehorses engaged in either flat (race distance 1,000-2,500 m) or jump racing (race distance 3,200-6,400 m).
Methods:
Cardiac auscultation and color flow Doppler (CFD) echocardiography were performed on 777 occasions. The associations between the presence and severity of either an audible cardiac murmur or valvular regurgitation assessed by CFD, and published, objective measures of race performance were determined using a standard regression approach.
Results:
The prevalence of murmurs and of regurgitation varied significantly between racetypes (P<.02), generally increasing from 2-year olds to chasers. There were no consistent associations between racing performance and either grade of murmur or regurgitation, whether the presence or absence of regurgitation or murmur, or only murmurs > or =3/6 or regurgitation > or =6/9, were considered.
Conclusions and clinical importance:
There were differences in prevalence and severity of murmurs of atrioventricular and aortic valve regurgitation between racehorses in different disciplines. Data also showed that neither regurgitation nor murmurs were negatively associated with Timeform rating, an index of UK racehorse quality, in any of the groups of racehorses studied.
Nineteen of 28 (67%) Greyhounds enrolled in the Blood Donor Program at The Veterinary Teaching Hospital, The Ohio State University (Columbus, OH), had a left basilar systolic murmur. Ten Greyhounds with murmurs and 9 without murmurs were evaluated to gain knowledge about the pathogenesis of this murmur. Echocardiograms were performed without sedation by means of a GE Vivid 7 Echocardiographic System with a continuous ECG; systolic arterial blood pressure (SABP) was measured with an Ultrasonic Doppler Flow detector model 811-B. The mean peak aortic velocity in the Greyhounds with murmurs (2.15 m/s; range, 1.8-2.2 m/s) was significantly higher than in the Greyhounds without murmurs (1.89 m/s; range, 1.6-2.0 m/s) (P < .001); there were no significant differences between groups for aortic valve or annulus diameter, fractional shortening, pulmonic velocity, SABP, hematocrit, serum protein concentration, or red blood cell counts. In this study, Greyhounds with soft, left basilar systolic murmurs had mildly (but significantly) higher mean peak aortic velocities than similar dogs without murmurs. In the dogs with murmurs (and higher velocities), we could not identify structural abnormalities, such as valvular lesions or other congenital defects. There was no inverse correlation between the systolic murmur and the higher hematocrit and red blood cell counts observed in this breed. This 1–2/6 basilar systolic murmur is common in Greyhounds, and it does not appear to be of any clinical consequence.
Turbulent blood flow may contribute to a variety of pathophysiological effects. Because of its postulated importance, this study was undertaken to determine whether turbulent flow does in fact occur in the human body. In 15 persons (seven normal, seven aortic valvular disease, one prosthetic aortic valve), point velocity was measured in the ascending aorta with a hot-film anemometer probe. In one normal individual with a high cardiac output, turbulent flow occurred above the aortic valve during peak flow which corresponded to a peak Reynolds number of 10,000. In the other six normal subjects (peak Reynolds numbers of 5,700-8,900), flow was highly disturbed during peak ejection. Each of the subjects with aortic valvular disease and the subject with a prosthetic aortic valve showed turbulent flow during nearly the entire period of ejection, with Fourier components of velocity of significant magnitude up to 320 Hz (the maximum frequency we could evaluate with the equipment available). The turbulence energy density was higher in subjects with abnormal valves (3.2-14.6 ergs/cm3), than in normal subjects (0.6-2.9 ergs/cm3). In subjects with aortic stenosis, turbulence was observed throughout the ascending aorta and in the innominate artery. In others, the turbulence dissipated more proximally. The results of this study indicate that turbulent flow can occur in the ascending aorta of subjects with normal cardiac function; and it occurs consistently in the ascending aorta of individuals with abnormal aortic valves.
To clarify the postulate that turbulence may produce ejection murmurs, point velocity and sound were measured in the ascending aorta of 13 subjects: six with normal aortic valves, six with aortic valvular disease, and one with a Bjork-Shiley prosthetic aortic valve. Velocity was measured with a catheter-tip hot film anemometer probe, and sound was measured with a catheter-tip micromanometer. Ejection murmurs detected intra-arterially were always found to be associated with turbulent or highly disturbed flow. Conversely, in the absence of intra-arterial sound during ejection, only minor disturbances of flow were detected. A linear relation between the sound energy density and turbulent energy density was shown (r = 0.92) and a linear relation between the acoustic power output (sound intensity) and turbulent power supply (r = 0.87) also was shown. Studies in vitro of sound and point velocity distal to a porcine valve inserted within a cast of the aorta, which permitted precise centering of the transducers along the axis of flow, confirmed these observations. When the power generated by the turbulence exceeded 3 ergs/sec per cm2, the murmurs were audible at the chest wall. The clinical gradation of the intensity of the murmurs increased as the power of turbulence increased. In conclusion, in this study we have demonstrated a clear association between turbulent blood flow and systolic ejection murmurs.
Cardiological findings in athletes are often similar to those observed in clinical cases. Electrocardiographic and cardiac imaging abnormalities as well as physical findings may be the same in both of these groups. Bradycardia and rhythm disturbances are the most common abnormalities in athletes. Most athletes with abnormal electrocardiograms are asymptomatic and numerous investigators have failed to detect heart disease in association with such electrocardiograms. In contrast to cardiac dysfunction observed in clinical cases, enhanced or normal ventricular systolic and diastolic function have been reported in athletes. In endurance athletes, this is associated with very high values for maximal aerobic power (VO2max). Absolute and body size-normalised cardiac dimensions in most athletes do not approach values from chronic disease states, and may not exceed echocardiographic normal limits. In addition, pathological and physiological enlargement appear to be biochemically and functionally different. Myosin ATPase enzyme expression and calcium metabolism are different in rats with pathologically or physiologically induced enlargement. The reported biochemical differences underlie systolic and diastolic dysfunction in pathological enlargement. Conversely, trained rodents and humans have demonstrated enhanced systolic and diastolic function. It is important to note that cardiac enlargement observed in athletes is the result of normal adaptation to physical conditioning and/or hereditary influences. Conversely, pathological changes result from disease processes which can lead in turn to reduced function, morbidity and mortality. Since the mid 1970s echocardiography has been used to compare cardiac dimensions in male endurance- and resistance-trained athletes. A sport-specific profile of eccentric and concentric enlargement has been documented in endurance and resistance athletes, respectively. Subsequent studies of athletes have examined factors such as age, sex and degree of competitive success to determine their contribution to these sport-specific cardiac profiles. Unique athletic subgroups have also been analysed and have included ballet dancers, rowers, basketball players and triathletes. However, there is a paucity of data on cardiac dimensions in female athletes. Finally, physical conditioning studies have also examined echocardiographic dimensions before and after endurance and resistance training. Significant enlargement of internal dimensions, wall thickness or left ventricular mass have been reported but such increases are relatively small and by no means universal. Several conflicting explanations for enlarged cardiac dimensions appear in the literature. Chronic volume and pressure haemodynamic overloading during physical conditioning has been proposed to explain eccentric and concentric cardiac enlargement in endurance- and resistance-trained athletes respectively. However, twin studies suggest that hereditary factors may be important determinants of cardiac dimensions and/or the degree of cardiac adaptability to physical conditioning.(ABSTRACT TRUNCATED AT 400 WORDS)
Auscultation was used to examine 545 horses for cardiac murmurs and some arrhythmias. The most significant finding was the high prevalence of right-sided holosystolic or pansystolic plateau-type murmurs compatible with a diagnosis of tricuspid regurgitation in National Hunt racing Thoroughbreds of all ages (16.4%). This condition was found in 4.7% of flat-racing Thoroughbreds, 3.7% of non-racing Thoroughbreds and Thoroughbred crosses, and in none of the ponies examined. High prevalences of left-sided early systolic murmurs (53%), left-sided early diastolic murmurs (23%), right-sided early diastolic murmurs (22%) and second degree atrioventricular block (23%) were found in racehorses of both types.
Colour flow Doppler echocardiographic examinations were performed on 15 horses; 10 Thoroughbreds and 5 Standardbreds; 9 mares, 5 geldings and 1 stallion; mean +/- s.d. 3.4 +/- 1.1 years. Cardiac murmurs were audible in 12 horses (80%), but these had characteristics consistent with functional murmurs in all horses. A standardised two-dimensional (2-D) and M-mode echocardiographic examination was unremarkable in all horses except that aortic valve prolapse was identified in 3 horses, tricuspid valve prolapse in 2 horses and mitral valve prolapse was present in one horse. Colour flow Doppler echocardiography revealed laminar antegrade flow in most sites but variance was noted in the right ventricular outflow tract in some horses. Small regurgitant jets associated with the aortic valve were seen in 12 horses (80%), with the tricuspid valve in 7 horses (46%), with the pulmonary valve in 4 horses (26%) and the mitral valve in 4 horses (26%). It was concluded that with colour flow Doppler echocardiography, as in other species, small regurgitant jets could be detected in many normal horses.
Most children have an audible murmur at some point from infancy through adolescence. Fortunately most of these murmurs are innocent. These murmurs are asymptomatic and require no follow-up care. On the other hand, pathologic murmurs are symptomatic and do require assessment by a pediatric cardiologist. Referrals are not only anxiety-provoking for the family but are also costly. The pediatric nurse practitioner must therefore be able to differentiate between the innocent and pathologic murmur. Auscultation of heart sounds is the most effective method used to assess murmurs. Given that innocent murmurs are asymptomatic, they require minimal follow-up care, and the expected outcome for a child with the diagnosis of such a murmur is excellent.
A study was undertaken to investigate the relationship between murmur intensity, murmur duration, duration to peak intensity and frequency components with degree of aortic stenosis in boxers. Measurements were made from phonocardiograms obtained from 35 boxers with ejection-type murmurs, and values were compared with those obtained for aortic flow velocity measured by Doppler echocardiography. Murmur intensity graded by auscultation was significantly correlated with aortic flow velocity (P < 0.001), and murmur duration, expressed as a percentage of systole was significantly correlated with aortic flow velocity (P < 0.001), independent of heart rate. Dogs with early systolic murmurs not exceeding 50 per cent of systole had aortic flow velocities of less than 1.5 m/second and no echocardiographic abnormalities, in contrast with dogs with murmurs of longer duration. Dogs with only high frequency components had lower aortic velocities than those that also had components in the medium frequency range (P < 0.01).
Haemorheological parameters in nine breeds of dog were examined. Whole blood viscosity at both high and low shear rates differed significantly between the breeds with a 50% difference between the highest and lowest viscosity at high shear rate and a 140% difference at low shear rate. Athletic breeds (Greyhounds, Deerhounds) had the highest whole blood viscosities. Differences in viscosity correlated well with differences in haematocrit between breeds. When the blood samples were adjusted to a standard haematocrit (45%), there were no significant differences in viscosity. This implied that other rheological factors such as cellular deformability and plasma viscosity did not vary significantly between breeds, and direct measurement showed this to be the case.
The cardiac morphology of 77 conscious Alaskan sled dogs before and after 5 mo of endurance training (20 km/day team pulling a sled and musher) was studied using two-dimensional and M-mode echocardiography. Subgroups included dogs with at least one season of previous training ("veterans") and dogs undergoing their first season of training ("rookies"). Training resulted in a significant (P < 0.05) decrease in resting heart rate (-15%) and significant increases in interventricular septal thickness (systole, 15%; diastole, 13%), left ventricular (LV) internal dimension in diastole (LVIDd, 4%), LV free wall thickness in systole (9%) and diastole (LVWd, 9%), and left atrial diameter (5%) in all dogs, but the increase in LVWd was greater in rookies (16%) than in veterans (7%). Training increased end-diastolic volume index (8%), LV mass index (24%), and heart weight index (24%) and decreased the LVIDd-to-LVWd ratio (-6%) but did not alter cardiac index. We conclude that increased LV mass attributable to LV dilation and hypertrophy is associated with endurance training in Alaskan sled dogs. Disproportionate LV wall thickening accompanying LV dilation suggests that cardiac morphological changes are due to volume and pressure loading. These training-induced changes are similar to those documented in human athletes undergoing combined isometric and isotonic training and differ from studies of dogs trained on treadmills.
The basics of pulsatile ejection dynamics are reviewed in order to clarify the relationships among left ventricular and aortic pressures, intra-left ventricular and aortic flow velocities, and cardiovascular sound. The principles of turbulent flow are examined using the Reynolds number concept, and the evidence for cause-and-effect relationships between turbulent flow and murmur generation is presented. Examples of hemodynamics and phonocardiography are given for normal subjects and are compared to patients with aortic stenosis and hypertrophic cardiomyopathy. The concepts presented are used to analyze the results of a new study suggesting increased intraventricular velocities as a new cause for systolic murmurs in adults.
The purpose of this study was to determine the frequency, clinical features and echocardiographic characteristics of increased intraventricular velocities (IIVs) in patients referred to the echocardiography laboratory for systolic murmur.
A subset of patients referred to the echocardiography laboratory for evaluation of a systolic murmur have IIVs in the absence of other recognized causes of systolic murmur.
We prospectively studied echocardiograms from 108 consecutive patients referred for evaluation of a systolic murmur. Clinical data were obtained from patient examinations and medical records.
The sole explanation for systolic murmur was IIVs in 16.7% of referred patients. Compared with those without IIVs, patients with IIVs had a higher ejection fraction (EF) (58.7+/-7.8% vs. 51.1+/-12.5%, p < 0.001), percent fractional shortening (42.3+/-9.7% vs. 31.0+/-11.4%, p < 0.0001), left ventricular (LV) mass index (181+/-70 vs. 152+/-48 g/m2, p=0.046) and prevalence of hypertension (73.3% vs. 51.7%, p=0.043) and a lower prevalence of segmental wall motion abnormalities (2.2% vs. 39.3%, p < 0.001).
Increased intraventricular velocities are a common cause of systolic murmur in this group of patients and should be included in the differential diagnosis of systolic murmurs in adults. The association of IIVs with LV hypertrophy should be a clinical consideration when these murmurs are identified.
To determine the prevalence of various types of heart murmurs in Thoroughbred racehorses and assess their association with performance by echocardiography and review of the horses' race records for the preceding 2 years.
Clinical and retrospective study.
846 Thoroughbred racehorses.
Cardiac auscultations were performed by 3 individuals; for 30 horses, Doppler echocardiographic examinations were also performed. Statistical analyses of race records for 753 horses were performed to assess association of heart murmurs with performance.
Heart murmurs were detected by cardiac auscultation in 686 of 846 (81.1%) horses. Systolic murmurs over the heart base were most common; 365 (43.1%) horses had systolic murmurs that were loudest over the pulmonary valve area, and 232 (27.4%) horses had systolic murmurs that were loudest over the aortic valve area. Systolic murmurs over the tricuspid valve area were detected in 241 (28.5%) horses, whereas systolic murmurs over the mitral valve area were detected in only 32 (3.8%) horses. Diastolic murmurs were much less common than systolic murmurs. Review of race records did not reveal a significant association between murmurs and performance.
Results suggest that heart murmurs are a common finding in racehorses; most of these heart murmurs do not appear to be clinically important.
Cardiac auscultation was carried out on 111 Thoroughbred horses age 2–5 years to test the hypothesis that athletic training might influence the development of atrioventricular (AV) valve regurgitation in young Thoroughbreds. Murmurs of valvular regurgitation were identified and graded on a 1–6 scale. There were 2 sources of auscultation data: 1) 55 2‐year‐old horses that were examined by auscultation before training commenced and 9 months later when at race fitness; 2) 56 horses age 2–5 years that were examined on one occasion only (25 2‐year‐olds, 23 3‐year‐olds, five 4‐year‐olds and five 5‐year olds). All horses in the second data set were in full training and racing regularly at the time of the examination. To conclude the study, 35 horses were selected randomly from both groups of horses and examined with colour‐flow Doppler echocardiography. The aim of the final part of the study was to check specificity and sensitivity of auscultation for detection of AV valve murmurs and therefore validate the auscultation findings.
Priorto training, the prevalence in 2‐year‐old racehorses of murmurs of mitral regurgitation and tricuspid regurgitation was 7.3% (4/55) and 12.7% (7/55), respectively. After training, the prevalence proportions increased to 21.8% (12/55) and 25.5% (14/55). After training, one horse developed a murmur characteristic of aortic regurgitation. The differences in murmur prevalence were statistically significant for mitral and tricuspid regurgitation (paired t test results: mitral regurgitation, P = 0.019; tricuspid regurgitation, P = 0.007), as were the differences in mean murmurgrade (P= 0.018 and P= 0.0006, respectively). There were no significant effects of age on the prevalence of valvular regurgitation in 56 horses examined at race fitness. Auscultation was a specific (specificity 100%) and reasonably sensitive method for detection of murmurs of mitral and tricuspid regurgitation (mitral regurgitation: positive predictive value 100%, negative predictive value 84%, tricuspid regurgitation: positive predictive value 100%, negative predictive value 65%).
These data suggest that the prevalence and grade of murmurs of mitral and tricuspid valvular regurgitation increase in 2‐year‐old Thoroughbreds after 9 months of athletic training. Whereas the effects of age and growth on the prevalence of murmurs cannot be ruled out from these data, this study suggests that there is an influence of athletic training on the development of atrioventicular valvular regurgitation in flat‐racing Thoroughbreds.
Systolic murmurs are common, and it is important to know whether physical examination can reliably determine their cause. Therefore, we prospectively assessed the diagnostic accuracy of a cardiac examination in patients without previous echocardiography who were referred for evaluation of a systolic murmur.
In 100 consecutive adults (mean [+/- SD] age of 58 +/- 22 years) who were referred for a systolic murmur of unknown cause, the diagnostic accuracy of the cardiac examination by cardiologists (without provision of clinical history, electrocardiogram, or chest radiograph) was compared with the results of echocardiography.
The echocardiographic findings included a normal examination (functional murmur) in 21 patients, aortic stenosis in 29 patients, mitral regurgitation in 30 patients, left or right intraventricular pressure gradient in 11 patients, mitral valve prolapse in 11 patients, ventricular septal defect in 4 patients, hypertrophic obstructive cardiomyopathy in 3 patients, and associated aortic regurgitation in 28 patients. In 28 (35%) of the 79 patients with organic heart disease, more than one abnormality was found; combined aortic and mitral valve disease was the most frequent combination (n = 22). The sensitivity of the cardiac examination was acceptable for detecting ventricular septal defect (100% [4 of 4]), isolated mitral regurgitation (88% [26 of 36]), aortic stenosis (71% [21 of 29]), and a functional murmur (67% [14 of 21]), but not for intraventricular pressure gradients (18% [2 of 11]), aortic regurgitation (21% [6 of 28]), combined aortic and mitral valve disease (55% [6 of 11]), and mitral valve prolapse (55% [12 of 22]). In 6 patients, the degree of aortic stenosis was misjudged on the clinical examination, mainly because of a severely diminished left ventricular ejection fraction. Significant heart disease was missed completely in only 2 patients.
In adults with a systolic murmur of unknown cause, a functional murmur can usually be distinguished from an organic murmur. However, the ability of the cardiac examination to assess the exact cause of the murmur is limited, especially if more than one lesion is present. Thus, echocardiography should be performed in patients with systolic murmurs of unknown cause who are suspected of having significant heart disease.
To compare cardiac physical examination with echocardiography for evaluating systolic murmurs.
Three databases were searched for studies comparing echocardiography and auscultation as to sensitivity and diagnostic accuracy: MEDLINE (Ovid Online), EMBASE, and Current Contexts. The quality of reported data is lowered by subjective interpretation of results of both cardiac physical examination and echocardiography, especially Doppler colour flow imaging.
In adults, functional systolic murmurs can usually be distinguished from organic murmurs. Pathologic murmurs frequently have one or more associated clinical abnormalities. If a clinician determines a murmur is benign, results of echocardiography are very likely to be normal, especially in young and middle-aged adults. According to current guidelines, echocardiography should not be ordered for "innocent" systolic murmurs in patients who are asymptomatic and have otherwise normal findings on examination. If patients with functional systolic murmurs could be identified and not routinely referred for echocardiography, great cost savings could be realized.
Echocardiography is not required for all patients with systolic murmurs and should not replace cardiac physical examination.
Our recent data have confirmed that maximum oxygen delivery in racing Thoroughbreds is positively correlated to left ventricular mass measured by echocardiography. A similar, but weaker relationship also exists between left ventricular mass and Timeform performance rating in commercial racehorses. The relationship of the Thoroughbred heart to racing success and the special problems that selective breeding for aerobic capacity have had in this species are reviewed in this article.
Inter-observer variation in the detection and grading of low intensity heart murmurs in boxer dogs was investigated. Six veterinarians with different levels of experience examined 27 boxers by cardiac auscultation. The dogs were auscultated before and after exercise, and the results were compared with phonocardiographic and echocardiographic examinations performed at rest and during two different stress tests. A subvalvular aortic ridge was identified in six dogs on two-dimensional echocardiography. Using dogs with low intensity murmurs or dogs free of heart murmurs, inter-observer agreement was positively correlated to the level of experience at rest (weighted kappa [kappa] 0.14 to 0.75), while the agreement was poor after exercise (weighted kappa 0.01 to 0.36). The presence of a subvalvular aortic ridge was associated with higher aortic flow velocities (P<0.002) and higher auscultatory murmur grading (P<0.001). There was an increase in murmur duration during one kind of stress test (P<0.001) and in aortic flow velocity during the other (P=0.001).
Cardiac auscultation remains a critical component of the pediatric examination and is the primary method of diagnosis for the common innocent murmurs of childhood. This article outlines the significance of auscultation and defines the skills important for the diagnosis and recognition of common cardiac murmurs in childhood. The origin of heart sounds and murmurs is reviewed, and an approach to pediatric murmur evaluation is presented. The seven innocent murmurs of childhood and adolescence are reviewed in detail. Further diagnostic evaluation and referral depends the clinician's confidence and experience in recognizing and correctly characterizing these murmurs.
To investigate the origin of the pulmonary systolic ejection innocent flow murmur (IFM), echocardiographic examinations were undertaken in 30 children with IFM and in a control group consisting of 28 healthy children without murmur. Compared to the controls, the diameters of the left ventricular outflow tract (LVOT) and aortic valve annulus and aortic valve area tended to be smaller, whereas stroke volume (SV) and cardiac output were slightly greater in children with IFM, but they were not statistically significant. Mean fractional shortening was significantly higher in children with IFM. Peak flow velocity of LVOT, right ventricular outflow tract, aorta, and pulmonary artery, mean velocity and velocity time integral of the aortic and pulmonary flow, and maximal acceleration of the aortic flow were all significantly higher in the IFM group compared to the controls. The variables of left-sided flow velocities in the same individuals with IFM were significantly higher compared to those derived from the right heart. The ratios of the SV to the LVOT diameter and to the aortic valve area were found to be significantly greater. It was concluded that IFM originates from higher blood flow velocities in the region of LVOT and aortic valve annulus, and that the increased flow velocity results from the larger SV passing through the relatively narrow LVOT and aortic valve in children with IFM.
Nineteen of 28 (67%) Greyhounds enrolled in the Blood Donor Program at The Veterinary Teaching Hospital, The Ohio State University (Columbus, OH), had a left basilar systolic murmur. Ten Greyhounds with murmurs and 9 without murmurs were evaluated to gain knowledge about the pathogenesis of this murmur. Echocardiograms were performed without sedation by means of a GE Vivid 7 Echocardiographic System with a continuous ECG; systolic arterial blood pressure (SABP) was measured with an Ultrasonic Doppler Flow detector model 811-B. The mean peak aortic velocity in the Greyhounds with murmurs (2.15 m/s; range, 1.8-2.2 m/s) was significantly higher than in the Greyhounds without murmurs (1.89 m/s; range, 1.6-2.0 m/s) (P < .001); there were no significant differences between groups for aortic valve or annulus diameter, fractional shortening, pulmonic velocity, SABP, hematocrit, serum protein concentration, or red blood cell counts. In this study, Greyhounds with soft, left basilar systolic murmurs had mildly (but significantly) higher mean peak aortic velocities than similar dogs without murmurs. In the dogs with murmurs (and higher velocities), we could not identify structural abnormalities, such as valvular lesions or other congenital defects. There was no inverse correlation between the systolic murmur and the higher hematocrit and red blood cell counts observed in this breed. This 1-2/6 basilar systolic murmur is common in Greyhounds, and it does not appear to be of any clinical consequence.
The aim of the study was to establish reference echocardiographic values for whippets, to compare these values with previously published reference values for the general dog population, and to determine whether there is an influence of gender and breeding lines on echocardiographic measurements. Echocardiographic parameters from 105 apparently healthy whippets without cardiac symptoms were used to establish reference values for the breed and to compare these values with two previously reported reference ranges. The coefficients of the allometric equation Y= aM(b), useful to reconstruct normal M-mode and two-dimensional average values for whippets of varying weights, were calculated, as well as the lower and upper limits of the 95% prediction interval. First, we found that whippets have a significantly larger left ventricular diameter, increased left ventricular wall, and interventricular septum thickness than expected, in diastole as well as in systole. Fractional shortening was significantly lower than the reference value. Second, comparing males and females, taking body weight differences into account, females had a significantly larger left ventricular diameter in diastole and systole. Minor differences were found between racing and show pedigree dogs. In conclusion, the results of this study confirm that breed-specific reference values are needed in echocardiography. In whippets, the values found in this study can be used as references in order to avoid overinterpretation of cardiac dilation, hypertrophy, and/or decreased contractility in these dogs.
Adoption of retired racing Greyhounds has become increasingly popular during the past decade. To date, research has focused on the physiologic and clinicopathologic peculiarities of Greyhounds but there is little published information on disease prevalence in the breed.
The objective of this study is to determine the prevalence of disease in retired racing Greyhounds.
In this study, 747 Greyhounds were used.
A standardized survey method was used, and survey responses were collected by an Internet survey. Owners could answer a survey for every Greyhound that they had owned since January 1, 2005.
Of the 692 eligible participants, 441 (63.7% response rate) completed surveys for 747 Greyhounds. The mortality rate for Greyhounds within the 2-year period was 15% (113 of 747 died). The most common cause of death reported was cancer (66 dogs, 58%), and the most common type of cancer listed as the cause of death was osteosarcoma (28 dogs, 25%). The most commonly reported groups of diseases or disorders were skeletal (232 dogs, 33%), skin (197 dogs, 28%), digestive (132 dogs, 18%), cancer (94 dogs, 13%), and endocrine (85 dogs, 11.9%). Forty-five percent of Greyhounds diagnosed with cancer and 6% of the overall population had osteosarcoma.
The results of this study can be used by veterinary researchers to continue to investigate the most common diseases in this population. As more retired racing Greyhounds enter the pet population, the results of this study will help educate veterinarians and owners about the most prevalent diseases in the breed.
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