Nifekalant Hydrochloride, a Novel Class III Antiarrhythmic Agent, Suppressed Postoperative Recurrent Ventricular Tachycardia in a Patient Undergoing Coronary Artery Bypass Grafting and the Dor Approach

A patient with 3-vessel coronary artery disease and left ventricular aneurysm underwent coronary artery bypass grafting combined with the Dor approach. Five days later, ventricular tachycardia following short-coupled ventricular premature contractions suddenly occurred and was not responsive to class IB drugs (lidocaine and mexiletine), requiring frequent electrical cardioversion. After the administration of a novel class III drug, nifekalant hydrochloride, this electrical storm of ventricular tachycardia was completely suppressed together with the disappearance of ventricular premature contractions. Nifekalant hydrochloride (MS-551), a pure K(+) channel blocker, might be effective for postoperative recurrent ventricular tachyarrhythmias that are refractory to other antiarrhythmic agents.