Reassessment of digoxin and other low-dose positive inotropes in the treatment of chronic heart failure.

Digoxin and other low doses of drugs that have inotropic properties may have an important role to play in the therapy of patients with chronic heart failure. There is convincing evidence that digoxin is effective in relieving the signs and symptoms of heart failure due to systolic dysfunction. While earlier results with some of the other agents have been disappointing, recent data suggest that a reevaluation of these agents is necessary. There is now compelling evidence that lower doses of these agents may be clinically useful without necessarily having any significant hemodynamic effects. The recent experience with vesnarinone is especially promising in showing that therapy with these agents may improve survival in addition to improving clinical status. It is becoming recognized that hemodynamic activity should not necessarily be a prerequisite for clinical utility for those agents. The neuroendocrine and electrophysiologic effects of many of these agents, including digitalis, remain incompletely characterized and may play an important role in their therapeutic benefit. It appears that certain drugs that have inotropic properties may be effective only when their inotropic effects are not readily demonstrated. Further research into the appropriate mechanisms of action and proper dosing of these drugs may lead to a renewed interest in the use of positive inotropes for chronic heart failure.