Vernakalant: A novel agent for the termination of atrial fibrillation

Purpose. The pharmacology, pharmacokinetics, safety, clinical efficacy, and role of intravenous vernakalant hydrochloride for the rapid conversion of atrial fibrillation (AF) to normal sinus rhythm are reviewed. Summary. Vernakalant, currently being evaluated by the Food and Drug Administration (FDA), for the termination of atrial fibrillation, differs in pharmacology from other antiarrhythmics; it achieves action potential interference through blockade of sodium and potassium currents. Vernakalant's actions appear to be directed at relatively atrial-selective potassium currents, which result in lengthening of the atrial action potential and prolongation of the atrial action potential plateau, while not significantly affecting the Q-T interval or the ventricular effective refractory period. As a result, the proarrhythmic effects observed with all other agents approved by FDA for the treatment of AF are eliminated. In clinical trials of vernakalant versus placebo, a statistically significant number of patients converted to normal sinus rhythm after receiving vernakalant. For patients with atrial fibrillation continuing for 3-72 hours, the median time to conversion was between 8 and 14 minutes, with 79% of those who converted remaining in sinus rhythm at 24 hours. Conclusion. Intravenous vernakalant, a novel, relatively atrial-selective antiarrhythmic agent, appears to offer an effective and safe approach to the rapid conversion of recent-onset AF to normal sinus rhythm.