Impaired distensibility of the left ventricle after stiffening of the right ventricle

Acute and chronic alterations of right ventricular (RV) wall properties can change left ventricular (LV) performance. We investigated whether and how stiffening of the RV free wall alters LV diastolic distensibility. We used cross-circulated isolated hearts, in which the LV and RV were independently controllable. Stiffness of the RV free wall was altered by intramuscular i njections of glutaraldehyde into the RV free wall after right coronary arte ry ligation. We measured circumferential and longitudinal regional lengths in the septum and LV free wall. During data acquisition, RV volume was held constant. After the RV free wall was stiffened by glutaraldehyde, the LV d iastolic pressure-volume relation shifted upward and became steeper. Import antly, stiffening of the RV free wall increased the diastolic regional area in the septum and LV free wall under constant LV volume. The augmented reg ional dimensions may result in enhanced regional tension under constant LV volume and may be related to the observed increase in LV diastolic intracav itary pressure. The impaired LV diastolic distensibility by stiffening of t he RV free wall may be at least partly explained by myocardial stretch, pro bably due to LV deformation.