Dependence of ventricular distensibility on filling of the opposite ventricle.

TAYLOR, ROGER R., JAMES W. COVELL, EDMUND H. SONNENBLICK, AND JOHN Ross, JR. Dependence of ventricular distensibility on jilling of the opposite ventricle. Am. J. Physiol. 2 13 (3) : 7 1 l-7 18. 1967.-The influence of filling one ventricle on distensibility of the opposite ventricle was examined in dogs. Distensibility of the left or right ventricle was consistently decreased in proportion to the filling of the opposite chamber. To quantify the effect of right ventricular (RV) filling on left ventricular (LV) distensibility in the intact circulation the coexisting LV and RV end-diastolic pressures (EDP) were determined over a wide range of ventricular filling induced by blood infusion. LV pressure-volume relations were then obtained in the arrested heart and each level of LV filling pressure was matched with the RV filling pressure found to coexist in vivo. The effect of RV filling on the LV volume when LVEDP was low (3 mm Hg) was not discernible. The effect was apparent when LVEDP was 5 mm Hg with the appropriate RV filling, the LV volume being decreased by 1.8 =t 1.2 (SD) ml. At an LVEDP of 20 mm Hg the reduction was 3.9 & 2.4 ml or 7.1 it 4.7 (35 of LV volume; LV volume at an LVEDP of 20 mm Hg therefore was 7.1 y0 smaller with the RV full than with the RV empty. This effect is considered to result from the sharing of a common septum and fiber bundles. The effect should be considered when the passive diastolic pressurevolume relation is compared with that in the beating heart and whenever ventricular function is examined over a range of cardiac filling pressures. It may also play an important role when either ventricle is acutely distended in disease states.