Limitations of echocardiography in the assessment of left ventricular size and function in aortic regurgitation.

Publisher Website
Google Scholar
Abstract
The optimal timing for prosthetic valve replacement in patients with aortic regurgitation (AR) depends on the identification of left ventricular (LV) enlargement and dysfunction. Whether this goal could be achieved reliably by echocardiography was evaluated in 22 patients with pure or dominant AR (AR group) in whom echocardiographic LV dimensions and performance indices were compared to corresponding dimension, volume and performance data obtained by single-plane and biplane angiography. Echocardiographic and single-plane angiographic comparisons were made in 18 patients with diseases other than AR (non-AR group). In the AR group, there was a moderately close correlation between the echocardiographic dimensions and single-plane right anterior oblique (RAO) angiographic volume (r [correlation coefficient] = 0.80; P < 0.001). The standard error of estimate was large (SEE .+-. 60 ml) and did not justify the use of a regression formula for calculating LV volume from echocardiographic dimension in individual patients. Substituting biplane for RAO angiographic volume did not improve the correlation (r = 0.78, SEE .+-. 63 ml, P < 0.001). In these patients, the echocardiographic calculation of LV ejection phase indices compared unfavorably with corresponding RAO (r = 0.31-0.38; P = NS [not significant]), left anterior oblique (r = 0.54-0.56; P < 0.05) and biplane angiographic data (r = 0.53, 0.54; P < 0.05). Comparison between echocardiographic dimensions and RAO angiographic volumes in the non-AR group exhibited a higher degree of correlation (r = 0.94; P < 0.001) and the SEE was half that seen in the AR group (P < 0.001). There was a clinically satisfactory correlation between echocardiographic and RAO angiographic indices of LV function (r = 0.81-0.84; P < 0.001). Single echocardiographic measurements of LV dimensions and function indices are clinically unsatisfactory and potentially misleading in patients with AR. This discrepancy may be related to the altered geometric configuration of the enlarged chamber in this disease state.