A comparison of left ventricular mass and volume using different echocardiographic conventions.

Left ventricular dimensions were measured on M-mode echocardiograms, both by the Penn Convention and the Recommendations of the American Society of Echocardiographers in a sample cardiac population. The measurements of interventricular septum and the posterior wall of the left ventricle were significantly larger (P less than 0.001) using American Society Recommendations compared to using the Penn Convention. However, the left ventricular internal dimension at end-diastole was significantly larger (P less than 0.001) when measured by the Penn Convention. As a result of the differences in left ventricular dimensions, the left ventricular mass indexed to body surface area was significantly higher (P less than 0.001) using American Society as opposed to Penn measurements. On the other hand, left ventricular volume indexed to body surface area was significantly higher (P less than 0.001) on Penn measurements than on American Society estimates. These differences should be considered in any study where criteria of normality are to be applied. Good positive correlation (r greater than 0.9) between Penn and American Society estimates of indexed left ventricular volume allowed development of a regression equation to convert volumes from one convention to another. As a result, an upper normal limit of 100 ml/m2 for indexed left ventricular volume is suggested for measurements made using the Penn Convention.