TORSADE-DE-POINTES

Torsade de pointes (TDP) is a polymorphic ventricular tachycardia with a particular electrocardiographic pattern of continuously changing (' 'twisting'') morphology of the QRS complex occurring in the setting of delayed myocardial repolarization (i. e., prolongation of the QT inte rval). TDP may develop in the setting of an idiopathic disorder (Jerve ll/Lange-Nielsen syndrome, Romano-Ward syndrome, sporadic long QT synd rome) or may be induced by pharmacologic agents which prolong the QT i nterval, as well as by other clinical circumstances under which repola rization is delayed (e. g., hypokalemia, hypomagnesemia, bradycardia) (acquired long QT syndrome). Since the treatment of TDP strongly diffe rs from that of conventional ventricular tachycardia, correct diagnosi s is critical as it guides the treating physician in selecting the app ropriate mode of therapy. In this paper mainly the electrocardiographi c criteria presently used for the correct identification of this unusu al form of ventricular arrhythmia are presented. Additionally, the pot ential mechanisms and therapeutic modalities of TDP are discussed.