Positive inotropic/vasodilator agents.

Beta-adrenergic sympathomimetic agents such as dobutamine and dopamine, and phosphodiesterase inhibitors such as amrinone, milrinone, and enoxamone, exert a direct positive inotropic effect upon the myocardium by causing an increase in cyclic AMP levels. The phosphodiesterase inhibitors also exert a substantial direct vasodilator effect. Both the sympathomimetic agents and the phosphodiesterase inhibitors can be of value in the acute, short-term management of myocardial failure. At present, the use of these agents for long-term therapy of congestive heart failure is unproven, and remains investigational.