LEFT-VENTRICULAR MASS AND WALL THICKNESS IN HYPERTENSION - COMPARISON OF M-MODE AND 2 DIMENSIONAL ECHOCARDIOGRAPHY IN 2 EXPERIMENTAL-MODELS

The performance of noninvasive echocardiography, both M mode and two dimensional, was achieved in conscious dogs, allowing the study of direct anatomic-echocardiographic correlations of ventricular wall thickness and mass. Forty-three dogs, 33 with normotension and 10 with experimental hypertension, were studied. Good correlation between measurements of wall thickness was found between M mode echocardiography and corresponding anatomic sites in the interventricular septum (r = 0.62, P < 0.01) and in the posterior left ventricular wall (r = 0.75, P < 0.01); echocardiography consistently underestimated septal thickness by 1.9 mm ± 0.3 (standard error of the difference), and posterior wall thickness by 1.6 mm ± 0.2. In contrast, calculations of left ventricular mass from M mode tracings (D3 formula) grossly overestimated left ventricular weight (+65 percent, P < 0.001). Accuracy of calculated mass was significantly improved by two dimensional echocardiography. In 19 dogs, calculations based on both short and long left ventricular axes together with average wall thickness obtained from the septal, posterior and anterolateral walls led to a highly significant correlation with left ventricular weight (r = 0.90, P < 0.0001). Two dimensional echocardiography was particularly useful in defining the presence of left ventricular hypertrophy in dogs with experimental hypertension in which there was increased thickness of the anterolateral wall with little change in the septal and posterior walls. © 1979.