Echocardiographic determination of left ventricular stroke volume index: Comparison to three-dimensional computer reconstruction

The accuracy of commonly applied echocardiographic techniques for evaluating the LV stroke volume in vivo is determined by referring to the left ventricular (LV) volume calculated from a three-dimensional computer reconstruction (3DCR). 3DCRs of the LV cavities of 9 healthy, young males were used to calculate the LV volume, stroke volume (SV), and stroke volume index (SVI). These values were compared to values obtained by nine different calculation techniques which use two-dimensional echocardiography (2DE) and Doppler interrogations (DI) at the ascending aorta (AA) and at the main pulmonary artery (PA). The results indicate that measurement of SV values by Doppler interrogation are significantly less sensitive to volume changes than those calculated from the 3DCR. Also, the SV measurements at the main pulmonary artery correlate better (r = 0.91) to 3DCR values than those obtained by measurements at the AA (r = 0.72). The highest correlation with the 3DCR based volumes was obtained using diameters measured by 2DE at two orthogonal planes (the four-chamber and short-axis planes) and applying the hemisphere cylinder model for volume computation (r = 0.95). Other methods gave lower correlations, ranging between 0.66 and 0.72.