Short-coupled variant of torsade de pointes. A new electrocardiographic entity in the spectrum of idiopathic ventricular tachyarrhythmias.

Abstract

BACKGROUND: Torsade de pointes is characterized not only by its particular ECG pattern but by its context of congenital or acquired long QT syndrome and the long coupling interval of the initial premature beat. METHODS AND RESULTS: We observed 14 patients aged 34.6 +/- 10 years (mean +/- SD) with no structural heart disease who presented with syncope related to a typical ECG aspect of torsade de pointes. However, there was no evidence of long QT syndrome, and the torsade had the unusual particularity of an extremely short coupling interval of the first beat or of the isolated premature beats (245 +/- 28 milliseconds). In 10 cases they deteriorated into ventricular fibrillation. Four patients had a familial history of sudden death. Only 2 patients had a tachyarrhythmia inducible by programmed stimulation. At Holter recordings the heart rate variability was globally and significantly depressed, the vagal limb of the autonomic nervous system being predominantly affected. During a mean follow-up of 7 years there were 5 deaths (4 sudden). Nine patients are alive, 3 with implanted defibrillators and 6 treated with verapamil alone. Unlike the other types of antiarrhythmic agents including beta-blockers and amiodarone, verapamil is in our experience the only drug apparently active on the arrhythmias; however, it does not prevent sudden death. CONCLUSIONS: The short-coupled variant of torsade de pointes should be identified because of their ECG pattern and the risk of sudden death in young adults with no structural heart disease.