Effect of mitral regurgitation on pulmonary venous flow pattern derived from transesophageal echocardiography

No abstract available.

Effect of mitral regurgitation on pulmonary venous flow pattern derived from transesophageal echocardiography

No abstract available.

Echocardiographic Changes in Cardiac Morphology and Function in Renal Transplant Recipients

BACKGROUND: Left ventricular hypertrophy is common in chronic renal failure patients and may contribute increased risk of cardiovascular morbidity and mortality. We evaluated the left ventricular morphology and function in renal transplant recipients to find the relationship between hemodynamic changes and morphologic and functional improvement after transplantation. METHODS: Serial echocardiographic evaluations were performed in 27 adults(20 men and 7 women) at the time of transplantaion and posttransplantation 1 month and 4 months. The average duration of hemodialysis was 16+/-24 months(mean+/-S.D.). RESULTS: At the time of transplantation, the hematocrit level was 21+/-6% and posttransplantation 1 month and 4 months, that was increased to 39+/-5% and 42+/-7%, respectively(p<0.001). Left ventricular mass index by echocardiography was decreased significantly from 246+/-87g/m2(pre-KT) to 169+/-38g/m2(post-KT 1 month) and 153+/-40g/m2(post-KT 4 months), respectively (p<0.001). Interventricular septal thickness and left ventricular posterior wall thickness were decreased significantly after 4 months of transplantation. Left ventricular systolic and diastolic dimensions were also decreased significantly after 1 month and 4 months of transplantation. Left ventricular volumes and cardiac output were also decreased significantly. But A/E ratio, ejection fraction and fractional shortening did not change significantly. CONCLUSION: These findings showed that pretransplant high output state was resolved radipidly(within 1 month) but the diastolic function did not improved after transplantation 1 month and 4 months.

Transesophageal Echocardiography: Technique, Anatomy and Clinical Applications

Transesophageal echocardiography(TEE) is a new acoustic window to the cardiac structures and great vessels via retrocardiac esophagus. Because of the close relation between the esophagus and the heart, higher transducer frequencies can be applied, therefore leading to improved resolution and more accurate images than transthoracic echocardiography. We describe our experience with the first 353 awake patients. The procedure was well tolerated by the patients and associated with no major complications, within examination 10 to 20 minutes. Clinical diseases which appear to be suited for TEE includes 1) evaluation of native valve diseases, particulary mitral valve, pathologic valvular abnormalities and color Doppler regurgitant flows ; 2) assesment of prosthetic heart valves to better define malfunction and important pathologic associations ; 3) congenital heart disease, particularly atrial septal defect ; 4) endocarditis and detection of vegetations and complications ; 5) detection of thrombus and tumors, size, location, morphology, stalk ; and 6) aortic pathology including atherosclerosis, aneurysm and dissection. We conclude that transesophageal echocardiography is a new imaging technique that is rapidly evolving into a major tool for general cardiac imaging in a variety pathologic conditions and is a safe and useful tool in patients. Future advances in probe technology will continue to expand its applications.

Visualization of Coronary Arteries by Color-Coded Transesophageal Doppler Echocardiography

The visualization of coronary arteries by transthoracic two-dimensional echocardiography has been used for over 10 years. In many cases, the imaging quality is too poor to allow an anatomic evaluation. During the last few years, transesophageal echocardiography has been shown to provide optimal imaging quality in virtually all patients and of all cardiac structures including the coronary arteries. The purpose of this study was to test the ability of transesophageal echocardiography in the visualiation of the coronary arteries and assessment of coronary blood flow by transesophageal two-dimensional pulsed Doppler echocardiography. We Studied 285 patients, 91 men and 194 women, aged 16 to 81 year(mean 50.6 year men, mean 54.2 year women). We have been used a 5-MHz phased array transducer with incorporated color-coded Doppler. The left main coronary artery was visualized 95.1%, left circumflex artery 27.4, left anterior descending artery 21.4% and the main stem of the proximal right coronary artery 45.1%. The time-sequential left anterior descending artery flow pattern generally consisted of a small late systolic component and a large diastolic component. The peak flow velocity in the proximal left anterior descending artery during diastole was 40.8+/-8.0cm/sec(integrity 7.6+/-0.9) and during late systole was 18.5+/-5.5cm/sec(integrity 2.9+/-0.9). There were no complications during and after examination. This study suggests that transesophageal color-coded Doppler two-dimensional echocardiography appers to be a feasible noninvasive technique for imaging the proximal left coronary artery and the left anterior descending artery flow is detectable from the transesophageal approach.

Experimental Study on Ventricular Fusion in Wolff-Parkinson-White Syndrome

WPW syndrome is the most common variaty of preexcitaton syndrome in which whole or part of ventricular muscle is activated by the atrial impulse earlier than would be expected if the impulse reached the ventricle by way of normal conduction system alone. WPW syndrome result from existence of accessory muscle bridge(atrio ventricular connection) between atrium and ventricle. The ventricular complex observed in WPW syndrome during periods of sinus rhythm is the result of fusion, with intial phase of ventricular activation representing excitation via accessory pathway and later forces produced by excitation of residual portions of ventricle via normal His-purkinje system. The variations in QRS aberrancy in WPW syndrome depend on varying degree of preexcitation. This experimental study was undertaken to increase our knowledge on the ventricular fusion in WPW syndrome through epicardial mapping after experimental induction of ventricular preexcitaion of WPW type. In 5 normal dogs, the heart was widely exposed through transverse thoracotomy and positioned in a pericardial cradle, then electric wires were fixed on the epicardium of right atrium and ventricular bases(anterobasal and posterobasal) areas of right ventricle, anterobasal and poaterobasal areas of left ventricle for atrial and ventricular pacing. Epicardial mapping was then performed during atrial pacing alone and during atrioventricular sequential pacing at the same rate. Atrioventricular sequential pacing was done with various short AV intervals(60-110 msec) for the purpose of premature stimulation on ventricular base. In mapping we used the grid system which consisted of 29 areas to cover the right ventricle and 23 areas to cover the left ventricle. We drew 9 epicardial ishochrone maps in 5 dogs. The epicardial data during atrio-ventriclar sequential pacing were then compared with those during atrial pacing at an identical rate to study the ventricular fusion in WPW syndrome. The results were as follows; 1) The preexciting wave spread radially from the stimulated basal area to the right and left(or anterior and posterior wall) and the apex. 2) Preexciting wavefronts collided with the normal wavefronts in a wide range of ventricular activation time. 3) Preexcitation widened according to the degree of the shortening of the AV interval. 4) The duration of ventricular activation was greater in preexcited ventricles than in normally activated ventricles. The more prematurely the ventricle was stimulated, the greater the duration of ventricular activation was.