Digitalis therapy--relevance of heart rate reduction.

Although digitalis is of limited antiarrhythmic value in patients with atrial fibrillation, it does control ventricular heart rate in the majority of patients at rest. It may be necessary, to add a beta-blocking agent or a calcium antagonist to control ventricular heart rate during exercise. This therapeutic approach should be controlled by exercise testing. In heart failure patients with sinus rhythm digitalis decreases heart rate, has antiadrenergic effects, and restores baroreceptor and parasympathetic activity. These actions are seen only in patients with severe heart failure due to left ventricular enlargement and low ejection fraction. In mild heart failure as well as in diastolic heart failure or cor pumonale, digitalis does not seem to be of clinical value. Thus, the use of digitalis in patients with sinus rhythm should be restricted to those with severe heart failure.