Adenosine Versus Fixed-Dose Intravenous Bolus Diltiazem on Reversing Supraventricular Tachycardia in The Emergency Department: A Multi-Center Cohort Study

Abstract

Background: Supraventricular tachycardia (SVT) is a common and therapeutically challenging cardiac dysrhythmia in the emergency department (ED). Adenosine and diltiazem are the most used pharmacological agents for SVT management, but few comparative studies exist.

Objective: To compare the efficacy of bolus intravenous (IV) adenosine versus diltiazem in the termination of spontaneous SVT.

Methods: This was a multicenter, retrospective, cohort study conducted in EDs in North Texas. Eligible subjects were adult patients presenting with stable SVT who received either a bolus of IV adenosine or diltiazem as the initial treatment. The primary outcome was the rate of successful conversion, which was defined as a sustained sinus rhythm within 30 min of the initial treatment. Secondary outcomes included time to conversion and response doses.

Results: A total of 344 cases were incorporated into the final analysis, 310 in the adenosine-first group and 34 in the diltiazem-first group. The rate of successful conversion trended higher for diltiazem; however, the difference was not significantly different (66.8% adenosine, 82.4% diltiazem, p = 0.08). The median time to conversion was significantly shorter for the adenosine group (3.0 min) to the diltiazem group (6.0 min, p = 0.02), with median response dosages of 12 mg and 15 mg, respectively. Of the cases that failed adenosine monotherapy, 18 (35%) were successfully rescued by diltiazem. Diltiazem also successfully controlled 77% of conversions to atrial fibrillation (AF) or flutter without hypotensive events.

Conclusion: This study showed that diltiazem and adenosine had similar conversion rates. In addition, diltiazem effectively rescued cases not responsive to adenosine.

Keywords: emergency department; pharmacology; supraventricular tachycardia.