Left ventricular volume change and inflow pattern in patients with prosthetic mitral valve were evaluated non-invasively by a pulsed Doppler flowmeter combined with an electronic beam sector scanning echocardiography. 20 subjects consisted of 10 patients with St. Jude Medical-27M (SJM, bi-leaflet center opening) and other ten with SJM-29M prosthetic valve. Left ventricular volume change was determined from left ventricular cineangiogram (LVG) based on the area-length method in 2 cases with sinus rhythm. Cardiac output obtained by thermodilution method was compared with that by Doppler's method. Velocities of
diastolic left ventricular volume changes by LVG were matched to transmitral flow velocities (TFV), but total volumes by Doppler's method were larger than those by LVG. Cardiac output by Doppler's method showed a good correlation with that by thermodilution's method (r = 0.79 in 27M and 0.69 in 29M).
These data indicate that TFV by Doppler flowmeter is useful for estimating instantaneous diastolic volume change of left ventricle and stroke volume non-invasively.