Minori Hama

Changes in transmitral and pulmonary venous flow velocity patterns after cardioversion of atrial fibrillation

To examine the recovery time of left atrial mechanical function after electrical cardioversion of atrial fibrillation, we recorded transmitral flow, pulmonary venous flow velocities, and interatrial septal motion during atrial systole within 24 hours (16 +/- 5 hours) and 10 days after cardioversion in 25 patients with atrial fibrillation, including 6 patients with hypertension, 4 with ischemic heart disease, 2 with alcoholic heart disease, 5 with dilated cardiomyopathy, and 8 with no evidence of underlying heart disease. With the exception of the five patients with dilated cardiomyopathy, the peak atrial systolic transmitral and pulmonary venous flow velocities, peak first systolic velocity of pulmonary venous flow, duration of both atrial systolic waves, and amplitude of the interatrial septal motion during atrial systole decreased markedly within 24 hours after cardioversion and increased 10 days after cardioversion. These results suggest that active atrial systolic and relaxant variables obtained from transmitral and pulmonary venous flow velocities may reflect left atrial mechanical function after cardioversion of atrial fibrillation.

Transesophageal Pulsed Doppler Echocardiographic Study of Pulmonary Venous Flow in Mitral Stenosis

For evaluation of pulmonary venous flow (PVF) in mitral stenosis, transthoracic and transesophageal echocardiography were performed in 33 patients with mitral stenosis and 20 normal controls. The peak systolic flow velocity of the PVF was significantly lower in patients with mitral stenosis and atrial fibrillation. The peak diastolic flow velocity of the PVF was significantly lower in the patients with mitral stenosis than in normal controls. The diastolic wave recorded as laminar flow in the mitral stenosis group showed a peak in the rapid filling phase with a gradually descending slope of velocity during mid to late diastole. There was a significant negative correlation between the peak diastolic flow velocity of the PVF and the pressure half time from transmitral flow obtained by continuous wave Doppler in the mitral stenosis group. These results demonstrate that evaluation of the PVF is helpful in understanding hemodynamic events between the left atrium and left ventricle in patients with mitral stenosis.

Assessment of Right-to-Left Shunt Flow in Atrial Septal Defect by Transesophageal Color and Pulsed Doppler Echocardiography

To investigate the clinical significance and problems of right-to-left (R-L) shunt flow dynamics in atrial septal defects, we performed transesophageal color and pulsed Doppler echocardiography in 30 patients with atrial septal defects of the ostium secundum type. The 30 patients consisted of 20 with a pulmonary artery systolic pressure of less than 40 mm Hg, four with a pressure of 40 to 60 mm Hg, three with a pressure of 90 mm Hg or more, two patients with pulmonic stenosis, and one patient with Ebsteins anomaly. R-L shunting was determined by the presence of a shunt flow signal across the defect during each cardiac cycle. The time of R-L shunt flow was compared with the various parameters obtained by echocardiography and cardiac catheterization. R-L shunt flow signals were detected at the following times: (1) at the onset of ventricular contraction or the closing phase of the tricuspid valve in five patients with isolated atrial septal defect. These patients showed an increase of mean right atrial pressure but had no severe pulmonary hypertension; (2) during ventricular systole in five of 26 patients with tricuspid regurgitation and one patient with Ebsteins anomaly. The tricuspid regurgitant signal was directed toward the ostium of the defect in three patients and was massive in the other patients; (3) during middiastole in three patients without pulmonary hypertension. These patients showed massive left-to-right shunt flow from end systole to early diastole; and (4) during atrial systole in three patients with severe pulmonary hypertension and two patients with pulmonic stenosis. The former, in particular, showed the aliasing signal as a high-speed shunt flow. In two of the three patients with severe pulmonary hypertension, R-L shunting continued from atrial systole to early ventricular systole and was also observed in early diastole. R-L shunt flow was detected in patients with atrial septal defects not only with pulmonary hypertension but also without pulmonary hypertension and was influenced by the right atrial pressure in the phase of tricuspid valve closing, the volume or direction of tricuspid regurgitation, rebound flow caused by massive left-to-right shunt flow, the grade of right ventricular distensibility or the complication of pulmonary hypertension, and complications with other cardiac anomalies. Thus R-L shunt flow in patients with atrial septal defects was detected easily by transesophageal color and pulsed Doppler echocardiography because of the high efficiency of this method for its detection.

Transesophageal echocardiographic evaluation of mitral regurgitation in hypertrophic cardiomyopathy: Contributions of eccentric left ventricular hypertrophy and related abnormalities of the mitral complex

This study was designed to evaluate the contribution of eccentric left ventricular hypertrophy and its related organic and spatial abnormalities of the mitral complex to the occurrence of mitral regurgitation in patients with hypertrophic cardiomyopathy We selected 45 consecutive patients with systolic mitral regurgitation by color Doppler echocardiography and performed transesophageal echocardiography in all patients. Eighteen patients were in the obstructive group and 27 patients were in the nonobstructive group of hypertrophic cardiomyopathy with asymmetric septal hypertrophy. Twenty subjects without any cardiac disorders served as the control group. The maximum area of mitral regurgitation was significantly greater in the obstructive group than in the nonobstructive group. Mitral regurgitation appeared more frequently during pansystole in the two groups with hypertrophic cardiomyopathy, particularly in the obstructive group. Mitral valve prolapse was observed in 20 (44%) of the 45 patients with hypertrophic cardiomyopathy. Distances between the posterior papillary muscle and anterior or posterior mitral anulus were significantly smaller in the two groups with hypertrophic cardiomyopathy than in the normal control group. In the obstructive group, the length of the anterior mitral leaflet and the thickness of the rough zone of the anterior mitral leaflet at mid-diastole were significantly greater than in the other groups. Systolic anterior motion was observed in all patients with obstructive cardiomyopathy and contact between the interventricular septum and the anterior mitral leaflet during early diastole was observed in 17 of the 18 patients in the obstructive group.(ABSTRACT TRUNCATED AT 250 WORDS)