Benedict Kingsley

Echocardiography: Clinical application in mitral regurgitation∗

Abstract The mitral valve echocardiogram in patients with solitary mitral regurgitation is, in general, characteristically different from normal healthy subjects. The amplitude of motion of the anterior leaflet echo and the slope of the E wave are conspicuously increased in most patients. Our experience indicates that echocardiography is a reliable and harmless procedure for the diagnosis of mitral reflux of different causation. Mitral regurgitation studied by cineradiography was most often attributed to rheumatic valvular disease, but regurgitation was sometimes secondary to ruptured chordae tendineae, papillary muscle dysfunction with and without cardiac failure, ventricular aneurysm and a redundant flail leaflet in Marfans syndrome. The echocardiogram is frequently abnormal in the patient with the late systolic murmur of modest mitral regurgitation and is useful in the differentiation of this murmur. It appears that the increased velocity and range of motion of the anterior leaflet in patients with mitral regurgitation are related to an increase in mitral valve flow during diastole and also to structural deformities of the valve. Alterations of the echocardiogram are noted after Aramine infusion, amyl nitrite inhalation and after surgical repair.

Echocardiography: Clinical application in combined mitral stenosis and mitral régurgitation∗

Abstract The echocardiogram was typically abnormal in patients with mitral valve disease. In the patient with combined mitral stenosis and mitral regurgitation, when the slope of the E wave was generally less than 50 mm./sec., dominant mitral obstruction and mild mitral reflux was diagnosed by left heart catheterization and cineradiography. When the slope was generally greater than 60 mm./sec., dominant mitral regurgitation was noted. The slope of the E wave was increased with increasing mitral reflux. Echocardiography was helpful in differentiating the pansystolic murmur of tricuspid regurgitation from mitral regurgitation. The echocardiogram is characteristic for mitral valve obstruction in the patient with severe mitral stenosis and secondary tricuspid regurgitation. In patients with aortic and mitral valve disease, the echocardiogram demonstrated the pathologic findings at the mitral valve. Echocardiography was also helpful in the detection of “silent” mitral stenosis and mitral regurgitation. Also, the systolic murmur of left ventricular outflow tract obstruction was differentiated from mitral regurgitation by echocardiography. In the former the slope was normal, and in patients with mitral reflux the slope was characteristically abnormal. The size of the cardiac chambers was determined by the “A” presentation. Right ventricular enlargement was suggested by the increased distance from the anterior chest wall to the most anterior portion of the mitral valve and left ventricular enlargement by an increased distance from the chest wall to the posterior wall.

Evaluation of induced pericardial effusion by reflected ultrasound

Abstract An experimental evaluation of the ultrasonic technic for the diagnosis of pericardial effusion revealed the following: 1. 1. The individual waveforms of posterior wall and pericardium could be differentiated after as little as 50 cc. of saline solution was infused into the pericardium. The waveform of the posterior wall could be quickly identified. When pericardial effusion existed the waveform of the posterior wall was separated by an echofree area from the waveform of the pericardium. 2. 2. The pericardium is capable of reflecting more ultrasonic energy than the posterior ventricular wall. 3. 3. Pleural effusion can probably be differentiated from pericardial effusion. 4. 4. The major interface of the left ventricular posterior wall is the blood-endocardium interface. The distance from the blood-endocardium to the epicardium-fluid or lung interface is a measure of wall thickness which compares favorably with direct measurements taken at autopsy.

Another look at echocardiography: Concepts in biomedical engineering∗

Abstract The ultrasonic waveform representing the motion of the anterior leaflet of the mitral valve provides precise timing for opening and closing of the mitral valve and for the opening snap. The largest amount of acoustic power in the cardiac cycle is generated from aortic valve opening and closing. Analysis of pulse-by-pulse echoes provides more accurate information. Pulse-by-pulse echoes provide a simple method for detecting turbulence at the mitral valve in patients with mitral regurgitation. The motion of the prosthetic ball and cage can be separated only by pulse-by-pulse analysis. Analysis of the echocardiogram may provide a simple, safe and painless technic for measuring stroke volume and cardiac output in patients with implanted prosthetic valves. The linear assumption of flow is known to be false, but the degree of nonlinearity is unknown. The pulse-by-pulse technic described here shows promise in terms of resolving the nonlinear flow.

Electronic Evaluation of Prosthetic Cardiac Valve Performance.

Excerpt A new noninvasive technique, octave band analysis, has been used for measuring objectively the sound level energy in decibels (db) and cutoff frequency in Hertz (Hz) of prosthetic valve sou...