Ventricular fibrillation in the Wolff-Parkinson-White syndrome

Ventricular fibrillation (VF) is a well-known but rare complication of the Wolff-Parkinson-White syndrome (WPW). Clinical and electrophysiological data of 23 patients with spontaneous VF were compared with data from 100 consecutive patients with WPW without VF but with symptomatic supraventricular tachycardia. The 23 patients were collected in a multicentre retrospective study in seven European centres. VF occurred in only one patient who was receiving anti-arrhythmic drugs, and was the first manifestation of the syndrome in six. No significant differences were found between those with VF and without VF in age, complaints of palpitations, syncope, and presence of structural heart disease. The retrograde effective refractory period of the accessory pathway, the atrial refractory period and the fastest atrial pacing rate with 1: 1 anterograde conduction over the accessory pathway were similar in both groups. Significant differences were found for sex, permanent pre-excitation on the electrocardiogram, type of documented supraventricular t achy arrhythmias, shortest RR interval ≦220 ms during spontaneous atrial fibrillation (AF), inducibility of supraventricular tachycardias, ventricular effective refractory period ≦190 ms, mean shortest RR interval during induced AF ≦, 180 ms and presence of multiple accessory pathways. Data from this retrospective study indicate that: (1) the anterograde conduction properties of the accessory pathway are a major determinant of the occurrence of VF in the WPW syndrome; (2) other markers for risk of VF are type of previously documented supraventricular tachyarrhythmia, documentation of more than one type of supraventricular tachycardia in the same patient and presence of two or more accessory pathways; (3) the finding of intermittent pre-excitation and a shortest RR interval during spontaneous AF longer than 220 ms, identifies a group of patients at low risk of VF.