Effects of Diazepam Addition to Standard Treatment of Atrial Fibrillation in Emergency Department Settings: A...

Background and Objectives: Diazepam, a GABA_A receptor agonist with sympatholytic properties, is sometimes co-administered with antiarrhythmic agents in the emergency management of atrial fibrillation (AF), yet evidence supporting this practice is remarkably limited. Given the established role of sympathetic activation in the initiation and maintenance of AF, we investigated whether adjunctive diazepam influences treatment outcomes. Materials and Methods: This single-centre retrospective cohort study included 72 hemodynamically stable patients presenting with AF to the emergency department of University Hospital Centre Split, Croatia. Patients were stratified by treatment strategy into a rhythm control group (n = 33, receiving any Class IC/III antiarrhythmic) and a rate control only group (n = 39, beta-blockers and/or digoxin). Diazepam was administered orally at the physician's discretion (median dose 5 mg). Primary outcomes were rhythm conversion and achievement of a heart rate < 110 bpm. Secondary outcomes included changes in heart rate, blood pressure, and time to therapeutic goal. Results: Diazepam was administered to 32 patients (44.4%). In the rate control stratum, spontaneous rhythm conversion was significantly higher with diazepam (40.0% vs. 9.5%; OR 6.33, 95% CI 1.06-37.78, p = 0.046), corresponding to a model-predicted increase in conversion probability from 8% to 33%. This effect was absent in the rhythm control group (64.3% vs. 64.7%; OR 0.98, p = 1.000). Diazepam increased the odds of achieving HR < 110 bpm by 3.46-fold (95% CrI 0.63-23.1, posterior probability of benefit 92%) in the rate control group. Diazepam-treated patients in the rate control group had longer median time to therapeutic goal (4.2 vs. 2.8 h, p = 0.005). In the rhythm control group, diazepam was associated with reduced variability in diastolic blood pressure response (p = 0.006). Conclusions: Adjunctive diazepam was associated with a significantly higher rate of spontaneous rhythm conversion in AF patients receiving rate control therapy only, consistent with sympatholysis removing a key factor sustaining the arrhythmia. This effect was not observed when Class IC/III antiarrhythmics were co-administered, suggesting that diazepam's benefit is context-dependent. These hypothesis-generating findings warrant prospective validation, with attention to thromboembolic risk in patients who convert unexpectedly.