Acute unilateral ventricular failure in the isolated dog heart

Acute left ventricular failure was studied in the isolated dog heart exposed to elevated aortic resistance. Experiments in which only the left ventricle performed mechanical work established that progressive changes in distensibility and contractility occurred. When exposure to the elevated resistance was prolonged, the failure became hemodynamically irreversible and there was a loss of responsiveness to increases in filling pressure. Experiments in which both ventricles worked under separately controllable hemodynamic conditions established that acute failure did not develop in the adjacent right ventricle. The observations suggest that the unilateral ventricular failure involved a permanent alteration of the distensibility and contractility of the wall of the left ventricle as a result of a process which permitted the right ventricle to retain normal function.