Efficacy and Safety of Intravenous Vernakalant in Rapid Cardioversion of Recent Onset Atrial Fibrillation: A Retrospective Single-Centre Study

Background: We use vernakalant, an intravenous anti -arrhythmic, to cardiovert paroxysmal atrial fibrillation (AF) into sinus rhythm. It is a relatively atrium -selective, early -activating potassium and frequencydependent sodium channel blocker with a half-life of 2 to 3 hours. Due to concerns regarding its safety profile, it is not Food and Drug Administration (FDA) -approved. Objective: This study aims to assess the efficacy of intravenous vernakalant in cardioversion of paroxysmal AF and the safety of its use. Methods: Patients with paroxysmal AF who presented to the American University of Beirut Medical Center (AUBMC) between 2015 and 2020 and received vernakalant for cardioversion were included. Patients did not receive vernakalant if they had any of the following: QTc > 440 ms, heart rate < 50 bpm, acute coronary syndrome within the last 30 days, second- and third-degree atrioventricular (AV) block in the absence of a pacemaker, severe aortic stenosis (AS), use of intravenous antiarrhythmics (class I and class III) within four hours of vernakalant infusion, systolic blood pressure <100 mmHg, and heart failure (New York Heart Association (NYHA) III or NYHA IV class). The primary endpoint is conversion to sinus rhythm for at least one minute within 90 minutes of the start of the vernakalant infusion. The secondary endpoint included the presence of these side effects: bradycardia, QTc prolongation, AV block, ventricular arrhythmias, hypotension, taste alteration/dysgeusia, sneezing, nausea, vomiting, paresthesia, cardiogenic shock, or death. Results: The study included 23 patients with paroxysmal AF (15 men, mean age 54 +/- 14 years). Fourteen patients (61%) cardioverted to sinus rhythm within 90 minutes of the start of the Vernakalant infusion. Seven patients (30%) reverted to sinus rhythm within 15 minutes after the first infusion. After treatment with vernakalant, four patients (17%) developed sinus bradycardia, and four patients (17%) developed firstdegree AV block. No patient had a QTc greater than 460 ms. None of the patients experienced sinus pauses, high-grade AV block, ventricular arrhythmias, hypotension, dysgeusia, sneezing, nausea, vomiting, paresthesia, cardiogenic shock, or death. Conclusion: Vernakalant had 61% efficacy in the rapid cardioversion of paroxysmal AF to sinus rhythm, was well tolerated, and had a low rate of adverse events in our study population.