Left ventricular effects on right ventricular developed pressure

Abstract

The possibility that left ventricular (LV) performance might affect right ventricular (RV) function through the myocardium was examined by using isolated, flow-perfused, paced rabbit hearts beating isovolumically. ReducingLV volume from its optimal volume to zero caused a 5.7% decrease (N = 10, Pless than 0.001) in right ventricular developed pressure (RVDP). Ligatingthe anterior ventricular branches of the left coronary artery which in the rabbit supply the LV free wall resulted in an additional 9.3% decrease in RVDP (N = 5, P = 0.05) within 3 min of ligation. Finally, cutting the LV free wall from the atrioventricular orifice to the apex (thereby preventing any developed LV free wall force during systole) caused a 45% further decrease in RVDP (N = 2, P less than 0.02). Cineradiographic study showed that the alterations in RVDP resulting from changes in LV volume and coronary occlusion correlated significantly (N = 5, P less than 0.01) with the magnitude ofseptal bulging into the RV cavity during systole. The results indicate thatalteration in LV free wall function and changes in LV volume can directly effect RVDP through the myocardium.