[Noninvasive evaluation of left ventricular function using new systolic time intervals obtained from continuous-wave Doppler echocardiography].

Left ventricular function was evaluated using parameters derived from the flow velocity waveforms at the ascending aorta as obtained at the suprasternal notch by continuous-wave Doppler echocardiography in 39 patients; 12 with chest pain but without coronary stenosis, eight with angina pectoris; and 19 with myocardial infarction. Peak flow velocity and the time interval from the beginning of the Q wave of lead II of the ECG to peak flow velocity (Q-V peak) correlated with specific invasive hemodynamic parameters, such as max dp/dt and (max dp/dt)/IP (IP: total left ventricular pressure at the same instant) during isometric contraction of the left ventricle measured with a catheter tip manometer, and left ventricular ejection fraction (LVEF) obtained by bi-plane cineangiography (using the area-length method). There was no correlation between the peak flow velocity and the invasive hemodynamic parameters. However, significant negative correlations were observed between the Q-V peak time and max dp/dt, with r = 0.40 (p less than 0.05), and between the Q-V peak time and (max dp/dt)/IP with r = -0.61 (p less than 0.01). A negative correlation was obtained between the Q-V peak time and LVEF (r = -0.75, p less than 0.01). The regression equation was LVEF = -0.67 x (Q-V peak) + 176. To compare the effectiveness for predicting LVEF between the Q-V peak and the established systolic time intervals as PEP and PEP/ET, these time intervals were measured from flow velocity waveforms invasively obtained with a catheter-type electromagnetic flowmeter inserted into the ascending aorta in 14 patients selected from the original subjects.(ABSTRACT TRUNCATED AT 250 WORDS)