Diltiazem Intravenous Bolus Doses in Atrial Fibrillation with Rapid Ventricular Response

Purpose The 2014 AHA/ACS/HRS guideline for acute rate control management of atrial fibrillation with rapid ventricular response (AF with RVR) recommends IV administration of a beta-blocker or a non-dihydropyridine calcium channel blocker to decrease heart rate (HR). 1 The primary objective of this study was to determine the efficacy of > 0.25mg/kg (low dose) or <0.25mg/kg (high dose) bolus doses of diltiazem in patients who present to the emergency department (ED) with AF with RVR. Methods A retrospective cohort study of patients presenting to the ED with AF with RVR. The primary endpoint was efficacy defined as HR <100 beats per minute or conversion to sinus rhythm within 1 hour of diltiazem bolus treatment without requiring additional doses of diltiazem or other rate control agents. The main secondary endpoints were treatment failure, time to achieve HR <100 bpm, mean HR at 30 minutes and 1 hour post diltiazem administration and incidence of adverse events. Results Achievement of efficacy was observed in 12.8% compared to 20% of patients who received diltiazem IV bolus dose of <0.25mg/kg and ≥0.25mg/kg respectively (p < 0.12). Incidence of hypotension was 8.5% vs 10.4% in the <0.25mg/kg and > 0.25mg/kg groups respectively (p < 0.17). Bradycardia occurred in 3.5% vs 3.3% in the <0.25mg/kg and > 0.25mg/kg groups respectively (p < 0.29). Conclusion There were no statistically significant differences in the achievement of efficacy and incidence of adverse events in patients who received low dose or high dose IV diltiazem.