Pharmacological Cardioversion with ‘Ibutilide’ in Atrial Tachyarrhythmias: Safety and Efficacy

Abstract

Background: Ibutilide is being increasingly tried as an agent for achieving acute pharmacological cardioversion of atrial tachyarrhythmias (AT). However, there is dearth of real-world data about the safety and efficacy of this drug. Methods: We performed a prospective observational study to characterise the patients undergoing successful cardioversion of AT with Ibutilide administered as per the institutional protocol. Results: Out of 68 patients with ATs, cardioversion was attempted in 33. Successful cardioversion to sinus rhythm was achieved in 23 (69%) patients. The underlying cardiac rhythm was atrial flutter (AFL) in 13 (39%), atrial fibrillation (AF) in 18 (55%), focal AT in 2 (6%) patients. Diabetes, hypertension, rheumatic heart disease, congenital heart disease, ischaemic heart disease, post-operative, moderate/severe mitral regurgitation, LV dysfunction (LVEF <55%) was noted in 15 (42%), 15 (42%), 4 (12%), 2 (6%), 7 (21%), 11 (33%), 9 (27%), 25 (75%). The mean duration of AT was 5 ± 3 months. Paroxysmal and persistent AT were noted in 23 (66%) and 10 (30%) respectively. Successful cardioversion was achieved with the first bolus and second bolus in 18 (54%) and 5 (15%) respectively. Six patients developed frequent PVCs/NSVT which subsided over time with IV magnesium. TdP was observed in one patient which was successfully cardioverted with DC. No deaths were seen during the study. The predictors of success were non-valvular aetiology, presence of AFL, ongoing antiarrhythmics, lesser mean duration of AT. Conclusions: Ibutilide can be safely administered for acute pharmacological cardioversion of ATs in a critical care setting.