The effect of supine rotation on left ventricular dimensions in man: a study using radio-opaque epicardial markers

It has been reported that patient rotation into the left lateral decubitus position (30 degrees rao) produces significant changes in the regression equations used for left ventricular volume determination and that normal values for echocardiographic left ventricular dimensions obtained from supine patients differ from those obtained after rotation. The purpose of this study was to establish whether patient rotation is associated with changes in left ventricular size and systolic function. The distances between left ventricular epicardial markers attached at the time of cardiac surgery were measured using biplane cineradiography in 14 patients in order to determine left ventricular dimensions before and after rotation. Supine epicardial left ventricular dimensions were not significantly different from those obtained with the patient rotated 30 degrees rao. These results suggest that reported changes in invasive and noninvasive measurements of left ventricular function associated with patient rotation are not primarily due to changes in left ventricular size.