Inotropic Therapy for Heart Failure

For those who have believed that the primary defect in chronic heart failure is a reduction in myocardial contractile force, the search for a potent, oral positive inotropic agent has been one of the most important efforts in cardiology. In recent years the search has focused on drugs that inhibit cardiac phosphodiesterase activity, since these drugs can increase myocardial levels of cyclic AMP and enhance the contractility of the failing ventricle. Early optimism about these drugs was based on their favorable and apparently sustained hemodynamic effects and on early reports of dramatic clinical improvement in patients with advanced heart failure. . . .