ACUTE ALTERATIONS IN SYSTOLIC VENTRICULAR INTERDEPENDENCE - MECHANICAL DEPENDENCE OF RIGHT VENTRICLE ON LEFT-VENTRICLE FOLLOWING ACUTE ALTERATION OF RIGHT-VENTRICULAR FREE-WALL

The purpose of the study was to examine whether systolic ventricular i nterdependence can be acutely altered by changes in the mechanical pro perties of the ventricular wall. In eight acute canine studies, we rel eased an aortic constriction during diastole. We measured right ventri cular (RV) pressure changes (dPr) caused by sudden changes in left ven tricular (LV) pressure (dPl). Measurements were obtained during contro l, 10 min after right coronary artery occlusion, and then 15 min after injecting glutaraldehyde into the RV free wall. By superimposing the pressure tracings of the beats immediately before and after the aortic release, the instantaneous pressure difference ratio (dPr/dPl) was ca lculated during systole. Maximal value of the pressure difference rati o decreased from control 0.11 +/- 0.04 to ischemia 0.08 +/- 0.03, (p < 0.05) and increased with glutaraldehyde 0.15 +/- 0.06; (p < 0.05). Th us, acute ischemia in RV free wall decreased the magnitude of systolic ventricular interdependence from LV to RV, white glutaraldehyde, whic h stiffens the RV free wall, increased the magnitude.