The incidence of congestive heart failure is increasing in the United States. This common syndrome is characterized not only by impaired ventricular function but also by an increase in some endogenous vasoconstrictor substances, including norepinephrine, angiotensin II, and arginine vasopressin. Although activation of the systems that release these substances is presumed to be compensatory (to maintain perfusion pressure during inadequate flow), the sympathetic nervous system, renin-angiotensin-aldosterone system, and arginine vasopressin may contribute to the pathogenesis of the syndrome. The excessive vasoconstriction present in heart failure likely produces a further burden on the failing myocardium. New strategies in therapy are being developed to counteract the activation of vasoconstrictor forces in congestive heart failure. Data indicate that selective blockade of the renin-angiotensin system is useful. Preliminary data suggest that inhibition of the sympathetic nervous system may be helpful, and inhibition of vasopressin in animals with heart failure is being studied. New and more selective therapy for heart failure may come from these studies.