Ventricular fibrillation during electrical cardioversion of pre-excited atrial fibrillation.

The Wolff-Parkinson-White syndrome can rarely present with pre-excited atrial fibrillation. In this condition the short refractory period of the accessory pathway can lead to rapid atrioventricular conduction. There is then a danger that at high heart rates the irregular broad complex tachycardia that results can deteriorate into ventricular fibrillation. The initial management of patients presenting in pre-excited atrial fibrillation requires cardioversion to sinus rhythm. This can be performed by DC cardioversion or pharmacological means. This paper describes the case of a patient presenting in pre-excited atrial fibrillation where electrical DC cardioversion lead to transient iatrogenic ventricular fibrillation.