[Sudden cardiac death after cardioversion].

An 83-year-old woman with heart failure due to atrial tachycardia with reduced left ventricular ejection fraction died after cardioversion. Holter monitoring showed a massive prolongation of the QT interval resulting in torsade de pointe tachycardia with lethal outcome. The only reason of the QT prolongation was impaired left ventricular (LV) function and atrial ectopy.