Epinephrine vs Dopamine for the Treatment of Bradycardia in the Emergency Department

In the emergency treatment of bradycardia, it is unclear if epinephrine or dopamine is better. Guidelines recommend either agent when atropine fails; however, they have not been directly compared, and evidence for either as a first-line therapy is limited. The objective of this study was to assess the efficacy of epinephrine versus dopamine infusion for the treatment of bradycardia in the emergency department (ED).

This multicenter, retrospective descriptive study included adults with a heart rate (HR) less than 50 beats per minute (bpm) treated with dopamine or epinephrine continuous infusion in the EDs or during rapid response activations from January 2021 to December 2025. Data was obtained from the electronic medical record using ICD-10 codes and manual chart review. The primary outcome was time to two consecutive HR greater than 60 bpm. Secondary outcomes included initial atropine use, additional hemodynamic support, mean arterial pressure (MAP) change, in-hospital mortality, hospital length of stay, and adverse drug reactions (ADRs). Student t-tests were used for primary and continuous secondary outcomes, and Chi-square & Fisher’s exact tests for nominal endpoints.

A total of 51 patients were included (41 dopamine; 10 epinephrine). Mean time to HR greater than 60 bpm was similar between groups (3 hours vs 2.7 hours; 95% CI -4.5 to 3.8; p = 0.86). Dopamine demonstrated outcomes comparable to epinephrine, including initial atropine use (65.9% vs 70%; p = 0.80), mean hospital length of stay (5.5 vs 6 days; p = 0.77), mortality (19.5% vs 30%; p = 0.18), target HR achievement (66% vs 70%; p = 0.80), and need for additional hemodynamic support (80% in both groups). Epinephrine produced a greater MAP increase (95% CI -33.21 to -1.12; p=0.037). In the dopamine group, average start and max doses during the first hour were 5 and 9 mcg/kg/min, respectively, compared with 0.1 and 0.2 mcg/kg/min in the epinephrine group. ADRs occurred in 20% and 40% of patients receiving dopamine and epinephrine respectively (p = 0.22), most commonly new-onset atrial fibrillation and tachycardia.

Dopamine and Epinephrine showed similar timing to two consecutive HR greater than 60 bpm, and other clinical outcomes were similar, except for a significantly greater MAP increase with epinephrine. However, the results are limited by the small sample size, and larger studies are needed to confirm.