Ultrasound Measurements of the Left Ventricle

A technique has been developed for measuring the distance between the interventricular septum and the posterior wall of the left ventricle using pulsed reflected ultrasound. This measurement was labeled left ventricular internal dimension (LVID) and was obtained at end-diastole (LVIDd) and at end-systole (LVIDs). These ultrasound dimensions were compared with angiocardiographic left ventricular volume determinations on 42 patients. The ultrasound LVID correlated well with the corresponding angiographic volume measurements, especially when LVID was cubed. The correlation between LVIDd3minus LVIDs3and left ventricular stroke volume was also highly significant. These initial results are quite promising and suggest that although there remain some unresolved problems and limitations, echocardiography ultimately may provide a clinically useful, noninvasive technique for quantitative estimations of left ventricular volumes in man.