Ventricular arrhythmia storms in postinfarction patients with implantable defibrillators for primary prevention indications: a MADIT-II substudy.

Background: Much of prognostic implications of ventricular arrhythmia storms remain unclear.

Objective: We evaluated the risk associated with electrical storm in patients with defibrillators in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II) study.

Methods: Electrical storm was defined as > or =3 episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF) in 24 hours.