Loading...
Although clinicians have been taught that QT prolongation is a risk factor for torsades de pointes (TdP), a potentially fatal arrhythmia, QT prolongation in some patients taking antipsychotic and antidepressant drugs does not inevitably result in TdP. To find a better predictor, European investigators compared electrocardiographic parameters in 36 patients with paroxysmal atrial fibrillation who had or did not have a history of Tdp (mean ages, 59 and 62). Testing was performed before and after an infusion of sotalol, which provokes abnormal repolarization and serves as a cardiac conduction stress test.
At baseline, QT interval corrected for heart rate (QTc) did not distinguish between patients with and without a TdP history. However, the gro…