Sinus node dysfunction: an adverse effect of lacosamide.

Lacosamide, a recently introduced antiepileptic drug, acts by enhancing the slow inactivation of voltage-dependent sodium channels. Cardiac conduction disturbances, namely atrial fibrillation and atrioventricular block, have been reported in patients with epilepsy. We report a patient with drug-resistant focal epilepsy who developed asymptomatic sinus node dysfunction following lacosamide use, which resolved on stopping lacosamide. This is the first report of sinus node dysfunction associated with lacosamide therapy. Wiley Periodicals, Inc.