Kazuyuki Kurokawa

Evaluation of left ventricular early diastolic performance by color tissue Doppler imaging of the mitral annulus

A noninvasive assessment of left ventricular (LV) diastolic performance by tissue Doppler imaging was performed in 56 patients (8 patients with atypical chest pain, 42 with coronary artery disease with a previous myocardial infarction, and 6 without a previous myocardial infarction) who underwent cardiac catheterization. Mitral annular velocity (MAV) during early ventricular diastole was obtained by M-mode color tissue Doppler imaging at the posterior corner of the mitral annulus. In each patient, the negative peak of the first derivative of LV pressure decay (peak -dP/dt) and a time constant of LV relaxation (tau) were calculated from the LV pressure waves obtained by a catheter-tip micromanometer. LV end-systolic volume index was measured from contrast left ventriculography. MAV during early diastole was significantly correlated with tau (r = -0.73, p <0.001), peak -dP/dt (r = 0.58, p <0.001), and LV end-systolic volume index (r = -0.63, p <0.001). On multivariate regression analysis with MAV during early diastole, tau and LV end-systolic volume index were selected as prime determinants (r = 0.80, p <0.001). These findings suggest that MAV during early diastole has a direct relation to LV elastic recoil as well as to LV relaxation. MAV during early diastole gives important information regarding LV behavior in late systole to early diastole where LV early diastolic performance is determined.

Paradoxical brain embolism caused by pulmonary arteriovenous fistula and coincident pulmonary embolism--a case report.

The authors encountered a very rare case of paradoxical brain embolism resulting from pulmonary arteriovenous fistula and coincident pulmonary embolism. Enhanced computed tomography was useful for diagnosing this infrequent condition.

Is the Blood Flow in the Left Ventricle during the Isovolumic Relaxation Period a Useful Parameter of Left Ventricular Systolic and Early Diastolic Performance

Left ventricular (LV) early diastolic performance is determined by LV behavior in the late systole to early diastole and may relate to the physical potential of patients. Isovolumic relaxation flow (IRF) velocity was obtained by continuous Doppler echocardiography in the left ventricle from the apex in 26 patients with atypical chest pain and 63 patients with coronary artery disease (CAD) with or without prior myocardial infarction (MI) who underwent cardiac catheterization. In each patient, a time constant of LV relaxation (τ) was calculated from the LV pressure waves obtained by a catheter-tipped micromanometer. The LV end-systolic volume index was measured using contrast left ventriculography. IRF velocity in patients having CAD with prior MI (24.8 ± 5.4 cm/s) was significantly less than in those with atypical chest pain (41.2 ± 9.6 cm/s). It was also significantly less than in patients having CAD without prior MI (37.3 ± 6.8 cm/s). IRF velocity significantly correlated with the time constant τ (r = –0.42, p < 0.001) and LV end-systolic volume index (r = –0.84, p < 0.001). This study indicates that IRF velocity obtained by continuous Doppler echocardiography in the left ventricle provides important information regarding LV systolic performance and early diastolic performance.