Proarrhythmia as a class effect of quinolones: increased dispersion of repolarization and triangulation of action potential predict torsades de pointes.

Background: Numerous noncardiovascular drugs prolong repolarization and thereby increase the risk for patients to develop life-threatening tachyarrhythmias of the torsade de pointes (TdP) type. The development of TdP is an individual, patient-specific response to a repolarization-prolonging drug, depending on the repolarization reserve. The aim of the present study was to analyze the underlying mechanisms that discriminate hearts that will develop TdP from hearts that will not develop TdP.