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

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.