Right ventricular contractility depression in chronically infarcted rats

We studied the in vitro mechanical performance of right ventricular strips obtained from male albino rats submitted to left coronary ligation for 30 days. The infarcted rats developed significant right ventricle hypertrophy together with a reduction of the isometric tension when compared to controls. The reduction was maintained even under positive inotropic intervention, i.e. the cumulative dose-response curves to calcium and adrenaline were displaced downward in parallel in the hypertrophied muscles. We conclude that after 30 days of left ventricle infarction the hypertrophied right ventricular myocardium presents a significant reduction of contractility.