The short-long-short-short sequence and polymorphic ventricular tachycardias storm.

We described a case of a patient who developed repetitive episodes of polymorphic ventricular tachycardias with a stereotypical pattern of initiation. A short-long-short-short (S-L-S-S) cardiac cycle sequence preceded all episodes and was considered to be the underlying initiative mechanism for these fatal arrhythmic events. In the patient, the paroxysmal atrial fibrillation was responsible for S-L-S-S sequence. It had been suggested that the electrophysiological mechanism by which the S-L-S-S cardiac sequence induces ventricular tachyarrhythmias was reentrant excitation, not early afterdepolarization and triggered activity. Early attempts to restore and maintain sinus rhythm by administration of antiarrhythmic drug with amiodarone, the patient experienced no atrial fibrillation and ventricular tachycardia recurrence.