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DMW - Deutsche Medizinische Wochenschrift 03/2013; 138(12):600-602. · 0.53 Impact Factor
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ABSTRACT: Cardiology and cardiothoracic surgery are closely related so that collaboration and communication are required to offer optimal therapy for patients. During the last decades many innovations have reduced the borders between cardiology and cardiothoracic surgery. Today, cardiologists may perform coronary interventions with good results that would have previously been the domain of coronary bypass surgery. In addition new valvular interventions have been developed, such as transfemoral or transapical aortic valve implantation and endovascular mitral valve reconstruction. New developments in cardiothoracic surgery have led to less invasive procedures and many surgical procedures can now be performed with minimally invasive techniques and without a cardiopulmonary bypass. To enable optimal therapy for patients, closer collaboration between cardiologists and cardiothoracic surgeons is required setting the stage for individualized therapy in the future.
Der Chirurg 11/2010; 81(12):1058-65. · 0.70 Impact Factor
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ABSTRACT: Increasingly complex techniques in cardiovascular medicine lead to a competitive partnership between cardiology and cardiac surgery. Common challenges will arise in the fields of coronary heart disease, heart valves, heart failure and rhythm therapy. For instance, coronary revascularization in acute myocardial infarction is no longer considered to exclusively be an interventional option. In comparison, the implantation of heart valves is increasingly carried out by cardiologists using interventional techniques. The latest designs of sutureless valves try to combine the benefits of conventional and transcatheter heart valves. Heart failure is the most common reason for hospital admission and thus an important therapeutic target for cardiology and cardiac surgery. New approaches in diagnostics, heart assist devices and cellular therapy meet this challenge. Conclusion: In the future only a sensitive and transparent collaboration across transsectoral borders will offer optimal therapy in cardiovascular medicine.
Der Chirurg 11/2010; 81(12):1066-72. · 0.70 Impact Factor
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ABSTRACT: Genetic engineering techniques led to an exponential increase in the number of transgenic and knock-out mouse models. For many genetically modified mice, high throughput echocardiography is an essential part of a systematic screening workflow. Many researchers perform mouse echocardiography in conscious animals to avoid anesthesia-induced impairment of cardiac function. However, it has been controversially discussed whether mice need to be habituated to handling before their cardiac function can be assessed. The aim of this study was to test the influence of training on parameters assessed during conscious mouse echocardiography. In addition, we tested whether a simple and fast echocardiography protocol has sufficient sensitivity and specificity for primary screening.
Examined parameters include fractional shortening, heart rate and respiratory rate. A total of 139 mice were examined in this study with a total of 587 echocardiograms. 103 mice were examined on five consecutive days (with examinations on day 1 - 4 regarded as training), 36 mice were only examined on day 1 and 5.
Fractional shortening, heart rate and respiratory rate did not show any statistically significant difference between day 1 and day 5 in both groups. The sensitivity and specificity of fractional shortening assessment for predicting a homozygote knock out genotype were 86 % and 97 %, respectively.
We conclude that conscious mouse echocardiography can be performed in untrained mice. Fractional shortening measurements may suffice for correct phenotyping in a high throughput setting.
Ultraschall in der Medizin 02/2010; 32 Suppl 1:S124-9. · 2.40 Impact Factor
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ABSTRACT: Adeno-associated virus (AAV)-6 or -9-pseudotyped vectors are suitable for efficient cardiac gene transfer after intravenous injection in mice. However, a systemic application in larger animals or humans would require very high doses of viral particles. Therefore, the aim of our study was to test if ultrasound-targeted microbubble destruction could augment cardiac transduction of AAV vectors after intravenous administration in rats. To analyze efficiency and specificity of gene transfer, microbubbles loaded with AAV-6 or -9 harboring a luciferase or enhanced green fluorescent protein (EGFP) reporter gene were infused into the jugular vein of adult Sprague-Dawley rats. During the infusion, high mechanical index ultrasound was administered to the heart. Control rats received the same amount of virus without microbubbles, but with ultrasound. After 4 weeks, organs were harvested and analyzed for reporter gene expression. In contrast to low cardiac expression after systemic transfer of the vector solution without microbubbles, ultrasound-targeted destruction of microbubbles significantly increased cardiac reporter activities between 6- and 20-fold. Analysis of spatial distribution of transgene expression using an AAV-9 vector encoding for EGFP revealed transmural expression predominantly in the left ventricular anterior wall. In conclusion, ultrasound targeted microbubble destruction augments cardiac transduction of AAV vectors in rats. This approach may be suitable for efficient, specific and noninvasive AAV-mediated gene transfer in larger animals or humans.
Gene therapy 08/2008; 15(23):1558-65. · 4.75 Impact Factor
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ABSTRACT: The development of second generation ultrasound contrast agents has extended the diagnostic scope of ultrasound imaging. Due to their physical characteristics, a therapeutic application of such microbubble based contrast agents has been promoted. Recently, several groups have demonstrated that ultrasound targeted microbubble destruction (UTMD) may deliver drugs or gene therapy vectors to organs accessible by ultrasound, thus providing a new technique for non-invasive, organ specific delivery of bioactive substances. Most applications in this field have been tested in cardiac models, but other organs can be treated as well. This article will give an overview of the background of UTMD and its non-cardiac applications.
Ultraschall in der Medizin 05/2006; 27(2):134-40. · 2.40 Impact Factor
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ABSTRACT: To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability.
Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2 = 0.92 versus r2 = 0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (kappa = 0.87 v kappa = 0.75, p < 0.05).
MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine.
Heart (British Cardiac Society) 04/2006; 92(3):350-6. · 4.22 Impact Factor
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A-E Dubart,
K G Carvalho da Silva,
G Korosoglou, R Bekeredjian,
A Hansen,
S Hardt,
M Rosenberg,
N Ferrari,
B Hoerig,
J Zehelein,
H Kuecherer
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ABSTRACT: Real-time contrast echocardiography (MCE) is a new promising technique for assessing myocardial perfusion. The purpose of this study was to test whether realtime MCE can be used to detect functionally significant coronary artery stenosis in patients with known or suspected coronary artery disease. Myocardial contrast echocardiographic studies were compared with nearly simultaneous 99mTc-sestamibi single photon emission computed tomography (SPECT) as a clinical standard reference to evaluate regional myocardial perfusion defects.
Real-time MCE based on continuous infusion of Optison (8-10 ml/h) was performed in 66 patients during standard 99mTc-SPECT dipyridamole (0.56 mg/kg x 4 min) stress testing. Images were obtained in apical 4- and 2-chamber views, each divided into 6 segments. Tracer uptake and myocardial opacification were visually analyzed for each segment by two pairs of blinded observers and graded as normal, mildly reduced, severely reduced, or absent. In 792 myocardial segments, myocardial opacification by MCE was uninterpretable in 143 (18%) segments and tracer uptake by SPECT was not clearly defined in 92 (12%) segments. Interobserver variability for MCE was good with concordance rates of 83% (kappa=0.72) for rest- and 86% (kappa=0.76) for stress images. Overall concordance between MCE and SPECT was good (83%, kappa=0.63) at a segmental level. In the diagnosis of fixed and reversible defects, and of normal perfusion, concordance rates were 73, 65 and 83%, respectively. When analysis was performed at the regional level, we found comparable levels of concordance rates for LAD (83%, kappa=0.59), LCX (86%, kappa=0.64) and RCA (80%, kappa=0.68) perfusion territories.
These findings suggest that realtime MCE is a clinically acceptable method to evaluate myocardial perfusion defects during dipyridamole stress testing.
Zeitschrift für Kardiologie 12/2004; 93(11):890-6. · 0.97 Impact Factor
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A.-E. Dubart,
K. G. Carvalho da Silva,
G. Korosoglou, R. Bekeredjian,
A. Hansen,
S. Hardt,
M. Rosenberg,
N. Ferrari,
B. Hoerig,
J. Zehelein,
H. Kuecherer
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ABSTRACT: Background
Real-time contrast echocardiography (MCE) is a new promising technique for assessing myocardial perfusion. The purpose of this study was to test whether realtime MCE can be used to detect functionally significant coronary artery stenosis in patients with known or suspected coronary artery disease. Myocardial contrast echocardiographic studies were compared with nearly simultaneous 99mTc-sestamibi single photon emission computed tomography (SPECT) as a clinical standard reference to evaluate regional myocardial perfusion defects.
Methods
Real-time MCE based on continuous infusion of Optison (8–10 ml/h) was performed in 66 patients during standard 99mTc-SPECT dipyridamole (0.56 mg/kg4 min) stress testing. Images were obtained in apical 4- and 2-chamber views, each divided into 6 segments. Tracer uptake and myocardial opacification were visually analyzed for each segment by two pairs of blinded observers and graded as normal, mildly reduced, severely reduced, or absent. In 792 myocardial segments, myocardial opacification by MCE was uninterpretable in 143 (18%) segments and tracer uptake by SPECT was not clearly defined in 92 (12%) segments. Interobserver variability for MCE was good with concordance rates of 83% (=0.72) for rest- and 86% (=0.76) for stress images. Overall concordance between MCE and SPECT was good (83%, =0.63) at a segmental level. In the diagnosis of fixed and reversible defects, and of normal perfusion, concordance rates were 73, 65 and 83%, respectively. When analysis was performed at the regional level, we found comparable levels of concordance rates for LAD (83%, =0.59), LCX (86%, =0.64) and RCA (80%, =0.68) perfusion territories.
Conclusions
These findings suggest that realtime MCE is a clinically acceptable method to evaluate myocardial perfusion defects during dipyridamole stress testing.Die Echtzeitkontrastechokardiographie (MCE) ist ein neues Verfahren zur Beurteilung der Myokardperfusion. Ziel der Studie war es zu testen, ob mittels Echtzeit MCE funktionell signifikante Koronarstenosen bei Patienten mit vermuteter oder bekannter koronarer Herzerkrankung erkannt werden knnen. Kontrastechokardiographische Untersuchungen wurden mit nahezu simultan durchgefhrten 99mTc-sestamibi SPECT-Untersuchungen verglichen. Die SPECT-Szintigraphie diente als klinischer Goldstandard zum Nachweis regionaler myokardialer Perfusionsdefekte. Echtzeit-Kontrastechokardiographische Untersuchungen wurden unter Verwendung einer kontinuierlichen Infusion von Optison (8–10 ml/h) durchgefhrt. Eingeschlossen wurden 70 konsekutive Patienten, bei denen aus klinischer Indikation eine pharmakologische Stressuntersuchung (99mTc-SPECT, Dipyridamol 0,56 mg/kg4 Minuten) durchgefhrt wurde. Apikale Vier- und Zweikammerblicke wurden in jeweils 6 Segmente unterteilt. Traceranreicherung und Myokardkontrastierung wurden von zwei unabhngigen Untersuchern visuell beurteilt (als normal, gering reduziert, stark reduziert oder fehlend). Die Myokardkontrastierung konnte in 143 von 792 Wandsegemten (18%) nicht adquat analysiert werden. Die Traceranreicherung war in 92 Segmenten (12%) nicht adquat analysierbar. Die Untersucherbereinstimmung war akzeptabel (Konkordanzraten 83% (=0,72) fr Ruhe- und 86% (=0,76) fr stressechokardiographische Untersuchungen). Die bereinstimmung zwischen MCE und SPECT-Befunden auf segmentaler Ebene war gut (83%, =0,63). Gute bereinstimmungen wurden auch bei der Erfassung fixer und reversibler Perfusionsdefekte und normal perfundierter Segmente gefunden (65, 73 und 83%). Bei der Auswertung einzelner Koronarversorgungsgebiete lagen fr alle drei Territorien gute bereinstimmungen vor (LAD, 83%, =0,59; LCX, 86%, =0,64 und RCA, 80%, =0,68). Diese Daten zeigen, dass sich die Echtzeitkontrastechokardiographie zur Erfassung von Perfusionsdefekten eignet.
Zeitschrift für Kardiologie 10/2004; 93(11):890-896. · 0.97 Impact Factor
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ABSTRACT: A recognized limitation of radioactive stents is the development of restenosis at the stent edges, known as the "candy-wrapper" effect. The mechanisms of this effect remain incompletely understood and controversial. The aim of this study is to assess the effect of endovascular irradiation on neointima formation and vascular remodeling. (32)P Palmaz-Schatz stents (1.5-4 microCi) were implanted in 11 patients with restenosis after previous percutaneous transluminal coronary angioplasty (PTCA). Intravascular ultrasound (IVUS) images of target sites and adjunct vessel segments were acquired both during intervention and after 6 months. The angiographic restenosis rate was 54%, and the MLD decreased from 2.21 +/- 0.6 mm to 1.38 +/- 0.4 mm at follow-up (P < 0.01). IVUS analysis demonstrated that late lumen loss was the result of neointimal tissue proliferation, which was nonuniformly distributed and exaggerated at both the central articulation and the distal stent edges. Negative remodeling did not contribute to restenosis. In contrast, we found a linear relationship between increase of area stenosis and a positive remodeling index (r = 0.84, P < 0.0001). Restenosis after implantation of (32)P Palmaz-Schatz stents was mainly the result of neointimal tissue proliferation which tended to be nonuniformly distributed in the stent articulation and edges. Negative remodeling or stent recoil was not observed. Cathet Cardiovasc Intervent 2001;54:41-48.
Catheterization and Cardiovascular Interventions 09/2001; 54(1):41-8. · 2.29 Impact Factor
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ABSTRACT: Elastic recoil and thrombus formation may potentially occur following directional coronary atherectomy (DCA) confounding the assessment of late vascular remodeling. Since intravascular ultrasound (IVUS) data on early outcome of DCA is not available, we used IVUS to investigate whether elastic recoil or thrombus formation can affect early (4 hr) outcome. Quantitative coronary angiography (QCA) and IVUS were performed in high-grade coronary lesions in 32 consecutive patients before, immediately after, and 4 hr after DCA. Late clinical follow-up was obtained after a maximum interval of 2 years. Significant acute elastic recoil was observed by both IVUS (19%+/-14%) and QCA (19%+/-12%), but there was no further recoil after 4 hr. DCA reduced plaque area by 51%+/-13%, an effect that was stable after 4 hr, indicating the absence of relevant thrombus formation. Residual area stenosis by IVUS was not related to the occurrence of late clinical events (n = 8). Mechanical recoil or thrombus formation do not hamper initial lumen gain achieved by DCA. Although QCA significantly underestimated residual plaque burden after DCA when compared to IVUS, the degree of residual area stenosis did not identify patients suffering from cardiac events on follow-up.
Catheterization and Cardiovascular Interventions 06/1999; 47(1):14-22. · 2.29 Impact Factor
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ABSTRACT: Intravascular ultrasound (IVUS) is frequently used as an adjunct to coronary angiography to guide revascularization procedures and, more recently, to estimate atherosclerotic plaque volumes. Although accuracy of IVUS imaging and analysis is crucial for these measurements, available data are scarce. The purpose of this in vitro study is to determine the extent to which transducer position and equipment-related factors influence measurement accuracy.
Cross-sectional views of tubular vessel phantoms (diameter 2-14 mm) were acquired using 3.2 French catheters in coaxially centered, eccentric and oblique positions. Catheters were sequentially connected to two different ultrasound systems (A and B) to estimate equipment-related variability. In system B, two software versions were used to analyze ultrasound images. Longitudinal views of phantom segments were reconstructed to document transducer misplacement.
Oblique transducer positioning resulted in a non-linear overestimation of phantom areas that was independent of lumen size and also resulted in dramatic distortions of three-dimensionally reconstructed phantom geometry. Eccentric positioning did not significantly influence measurement accuracy. In coaxial positioning, differences between measured and true areas increased non-linearly from 0.36 to 4.5 mm2 in system B and in a linear fashion from -0.01 to 2.68 mm2 in system A with increasing phantom diameters. Relative differences decreased from 11.4% to 2.9% with increasing reference areas in system B (positive off-set error). When using updated software in system B, the off-set error was negative and relative error diminished from -1.34% to 0.44% with increasing phantom size.
Transducer position and equipment-related factors influence the accuracy of intravascular ultrasound, which may lead to misinterpretation of vessel size and geometry even in straight vessel segments. Transducer position may be controlled by the reconstruction of longitudinal images. Ultrasound equipment should be calibrated before using it for quantitative measurements.
The Journal of invasive cardiology 05/1999; 11(4):207-12. · 1.84 Impact Factor
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ABSTRACT: Intravascular ultrasound (IVUS) has emerged as an important diagnostic method for evaluating vessel diameter and vessel wall motion. To evaluate the validity of IVUS in assessing changes in the pressure-diameter relationship we compared measurements of abdominal aortic diameters derived from IVUS with those simultaneously obtained at the same site using implanted sonomicrometers in five chronically instrumented conscious dogs and in seven acutely instrumented anesthetized dogs. Five hundred eighty beats were analyzed to obtain peak systolic and end-diastolic diameters and to calculate aortic compliance at different blood pressure levels induced either by an aortic pneumatic cuff or by intravenous injections of nitroglycerin or norepinephrine. IVUS agreed closely with sonomicrometer measurements at different blood pressure levels. However, IVUS slightly but significantly underestimated aortic diameters by 0.6 +/- 0.7 mm for systolic diameters (P < 0.001) and by 0.7 +/- 0.6 mm for diastolic diameters (P < 0.001) compared with the sonomicrometer measurements. We conclude that IVUS is a feasible and reliable method to measure dynamic changes in aortic dimensions and has the potential to provide ready access to assess aortic compliance in humans.
The American journal of physiology 04/1999; 276(3 Pt 2):H1078-85.
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ABSTRACT: To investigate to what extent anatomic structures of the tubal wall can be identified reproducibly and whether altered areas can be detected and delimited by intraluminal ultrasound.
Standardized in vitro experiment with descriptive evaluation of findings, comparative analysis of apparative and morphologic data, and determination of interobserver variability (video documentation, blinded reviewer).
Department of Gynecology and Obstetrics, University of Heidelberg, Germany. SPECIMEN(S): Seventy-two human and pig fallopian tubes.
Catheterization with a 2.9F or 3.2F ultrasound catheter and sonographic depiction of the fallopian tube, with either simultaneous manual and sonographic wall-thickness measurement or coagulation of the tubal wall.
A correlation coefficient of r = 0.76 for manual and sonographic tubal wall measurements and K = 0.88 (with 95% confidence interval of 0.74-1.0) for interobserver variability in recognizing coagulated areas.
Tubal wall anatomy and artificially altered (coagulated) areas were displayed reproducibly with intraluminal ultrasound, thus giving a characteristic, recognizable pattern of the tubal wall.
These in vitro experiments provide evidence that intraluminal ultrasound may expand the current diagnostic possibilities in cases of tubal pathology, providing nonsurgical access to the tubal wall.
Fertility and Sterility 08/1998; 70(1):161-4. · 3.56 Impact Factor
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