Comparison of Diltiazem and Metoprolol in the Management of Acute Atrial Fibrillation or Atrial Flutter
Status:
Completed
Trial end date:
2010-11-01
Target enrollment:
Participant gender:
Summary
Acute atrial fibrillation is the most common sustained, clinically significant dysrhythmia
encountered in the emergency department (ED) and the most common dysrhythmia treated by
emergency physicians. Atrial flutter is less common than atrial fibrillation but its
management in the ED is very similar, and the majority of patients with atrial flutter also
have atrial fibrillation. Symptomatic relief and ventricular rate control are generally the
primary therapeutic objectives in the ED management of acute atrial fibrillation and flutter
(AFF). The need for swift, appropriate action by the emergency physician is highlighted by
the fact that up to 18% of patients with AFF develop potentially life-threatening
complications such as congestive heart failure, hypotension, ventricular ectopy, respiratory
failure, angina and myocardial infarction.
Both beta-blocking agents and calcium channel blockers are commonly used to treat AFF in the
ED. Metoprolol is the most commonly used beta-blocker; and diltiazem is the most frequently
used calcium channel antagonist.[8] Diltiazem was released by the FDA for treatment of AFF in
1992. Shreck et al. were the first to demonstrate both the efficacy of diltiazem in the ED
management of AFF with rapid rate and its clear superiority over the previously most commonly
used pharmacologic agent, digoxin.
To date, only one prospective, randomized trial has compared the effectiveness of a calcium
channel blocker (diltiazem) with a beta-blocker (metoprolol) for rate control of AFF in the
ED. Despite the relatively small sample size (n=20 in each group) the authors concluded that
both pharmacologic agents were similarly effective. In order to test this finding, the
investigators conducted a prospective comparison of metoprolol and diltiazem for the
management of patients presenting to the ED with AFF with rapid ventricular rate.