Pirmenol hydrochloride-induced QT prolongation and T wave inversion on electrocardiogram during treatment for symptomatic atrial fibrillation.

Pirmenol hydrochloride is a new orally effective, long-acting antiarrhythmic agent currently used in patients with supraventricular and ventricular tachyarrhythmias. We report on a 56-year-old female who exhibited drug refractory paroxysmal atrial fibrillation, in which marked prolongation of the QT interval and T wave inversion on electrocardiogram was demonstrated reproducibly shortly after the administration of oral pirmenol therapy. The plasma concentration of pirmenol was at a subtherapeutic level and the lymphocyte stimulation test was positive in this patient. Thus, an immunological mechanism might be involved in the mechanism of pirmenol-induced QT prolongation and T wave inversion on the electrocardiogram.