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Biomedical subjects

T Owaki

Publications and source records attributed to T Owaki.

44 records · Page 3Linked to original sources
PubMed1976

Cord-like aortic valve vegetation in bacterial endocarditis. Demonstration by cardiac ultrasonography. Report of a case.

The ultrasonic features in a case of bacterial endocarditis in which a highly mobile, cord-like vegetation, attached to the noncoronary cusp of the aortic valve, are reported. The echocardiogram demonstrated abnormal echo patterns in the left ventricular outflow tract in diastrole which were continuous with similar echoes in the aortic root. While these findings did not differ from the previously reported manifestations in cases of flailing aortic valve leaflets, the cardiac ultrasonogram distinguished this vegetative growth. Cardiac ultrasonography revealed a cord-like characteristic, showed the movement of the entire growth into the left ventricular outflow tract in diastole and into the aorta in systole, and allowed estimation of the size of the vegetation. We conclude that cardiac ultrasonography can help in differentiating aortic valve leaflet flail and vegetations in endocarditis.

Adult↗
PubMed1975

Echocardiographic diagnosis of endocardial cushion defects.

Sixteen patients with endocardial cushion defects were studied by echocardiography and ultrasonocardiotomography. Three characteristic findings, common to both complete and partial forms, were observed. They were the ostium primum defect of the interatrial septum, the left ventricular outflow narrowing and the atrioventricular valve abnormalities which are the anatomic bases of endocardial cushion defects. Several additional findings were observed in patients with complete form. Most strikingly, the anterior leaflet echo locating in the left ventricle had the direct connection to that in the right ventricle without the interposition of the interventricular septum by echocardiogram. Ultrasonocardiotomogram, on the other hand, demonstrated beautifully the common anterior leaflet and the high inteventricular septal defect. There were, in addition, the absence of the paradoxical motion of the interventricular septum and the diffuculty in detecting the interatrial septum. The intact interatrial septum continuous with the anterior mitral leaflet was demonstrated in patients with the interventricularseptal defect of atrioventricular canal type, in which there were the typical abnormalities in the atrioventricular valves and the left ventricular outflow narrowing as well. This study indicates that ultrasonic examination may provide a direct, yet noninvasive method in the diagnosis of various types of endocardial cushion defects.

Adolescent↗
PubMed1975

Ultrasonic diagnosis of ventricular aneurysm.

Fifteen patients with ventricular aneurysm were selected based on the following 3 criteria: 1) electrocardiographic evidence of old myocardial infarction, 2) presence of abnormal precordial impulse, 3) presence of dyskinesis or akinesis with diastolic bulging of the ventricular cavity by angiocardiogram. Eight patients had anterior left ventricular aneurysm and 7 apical aneurysm. The characteristic abnormal precordial impulse was diminished or absent A wave, pre-upstroke retraction, late systolic bulge, and diminished rapid filling wave, all of which were recorded over the restricted area of the broad precordial impulse. M-mode echocardiogram revealed increased or normal excursion of the posterior left ventricular wall. However, abnormal motion of the anterior left ventricular wall was detected in all, if the transducer was located over the abnormal precordial impulse or slightly inside of it. Compound M-mode echocardiographic scan toward the abnormal precordial impulse was able to detect asynergy of the anterior left ventricular wall and the apex, and distinguish it from motions of the interventricular septum and the anterior right ventricular wall. Abnormal motion of the anterior left ventricular wall was paradoxical in 13 patients and flat in the others. Systolic posterior mortion of the posterior left ventricular wall was detected in 2 patients with apical aneurysm. Cardiac ultrasonogram scanning over the abnormal precordial impulse demonstrated the bulging of the ventricular cavity in either systole or diastole depending on the site of lesion. There was a good correlation between cardiac ultrasonography and angiocardiography with respect to the site of lesion. Our study indicates that this method is useful in the diagnosis of anterior and apical aneurysm which ordinary technique failed to detect.

Angiocardiography↗
PubMed1975

Study of posterior left atrial wall motion by echocardiography and its clinical application.

Echocardiographic tracings of posterior left atrial wall motion were examined in 30 normal subjects, 17 patients of mitral stenosis with sinus rhythm and 31 coronary patients with elevated left ventricular end-diastolic pressure. Because of the plane of the posterior left atrial wall motion and the angle of the sound beam, usually the postero-inferior portion of the left atrial wall was recorded. In normal subjects, there were 3 positive waves (A,C,V waves) and 2 negative waves (X and Y waves). The A wave during atrial contraction period occurred in the closing motion of the mitral valve and was initiated by a slight negative wave. The fourth heart sound was consistent with the ascending limb of the A wave. The C wave coincided with the first heart sound followed by the pronounced negative depression (X wave). The X trough coincided with the beginning of the mitral valve opening in early diastole and was the deepest point in the motion curve. The V wave was a peaked anterior motion during rapid filling period and followed by the third heart sound. The Y wave was a slight negative depression following the V wave, and its trough occurred when the both leaflets of the mitral valve assumed a semiclosed position. In both mitral stenosis and coronary artery disease, significant increase (p less than 0.01) of the A wave excursion and significant decrease (p less than 0.01) of the V wave excursion were observed, resulting in marked increase (p less than 0.01) of the A/V ratio. The slope of the ascending limb of the V wave was also decreased apparently in both conditions. These findings might reflect increased resistance to left atrial emptying in mitral stenosis and decreased left ventricular filling rate in coronary artery disease. This study shows that echocardiographic examination of the posterior left atrial wall motion is feasible and useful in estimating the presence of either mitral stenosis or decreased left ventricular filling rate.

Adolescent↗