Calcium channel blockers for heart rate control in atrial fibrillation complicated by congestive heart failure.

OBJECTIVES

To review the safety and efficacy of verapamil and diltiazem with respect to ventricular response in atrial fibrillation (AF) in the setting of left ventricular (LV) systolic dysfunction.

DATA SOURCES

Pertinent articles were identified through a MEDLINE search of the English language literature from 1984 to 1993, followed by a manual search of the bibliographies of pertinent articles.

STUDY SELECTION

Studies selected were case reports, controlled trials, review articles and editorials.

DATA EXTRACTION

Effects of verapamil and diltiazem on hemodynamics, ventricular response in AF, clinical parameters and mortality were reviewed.

DATA SYNTHESIS

There are limited data about the effects of verapamil and diltiazem on ventricular function in patients with congestive heart failure. In vitro diltiazem has fewer negative inotropic effects than verapamil. Clinically there are some reports of hemodynamic and clinical deterioration in patients with significant LV dysfunction given verapamil although most patients improve with verapamil. There are more data concerning diltiazem in the setting of AF complicated by congestive heart failure. The drug does not appear to exacerbate heart failure, although hypotension can result. In chronic AF complicated by heart failure, there is concern that diltiazem may increase mortality. Options for therapy are digoxin, beta-blockers and atrioventricular node ablation.

CONCLUSIONS

Calcium channel blockers may have a role in the acute reduction of ventricular response in patients with AF complicated by congestive heart failure; however, their safety in chronic heart rate control remains to be proven.