Multiple mechanisms of tachycardias in a patient with the Wolff-Parkinson-White syndrome

A serious cause of panic attack

We report on a case of a patient with atrial fibrillation in the setting of Wolff-Parkinson-White syndrome. The patient underwent synchronized electrical cardioversion, typically considered safe and effective, which resulted in a dangerous complication for the patient (degeneration into ventricular fibrillation). Discussion of common rhythm disturbances in WPW and management strategies are reviewed.

Effect of intraatrial reentry on initiation of atrioventricular reentrant tachycardia

We studied the effect of intraatrial reentry (IAR) on initiation of orthodromic reentrant tachycardia (ORT) in 150 patients with Wolff-Parkinson-White syndrome using His-bundle recording and the atrial extrastimulus technique. IAR was initiated by premature atrial stimulation in 44 patients (29%), and it was followed by ORT in 16 patients (11%). In 8 patients (5%), IAR promoted the initiation of ORT, whereas in 5 patients (3%), IAR inhibited the initiation of ORT. These findings suggest that ORT is frequently induced following IAR. IAR, which was frequently observed during electrophysiological studies, seems to play an important role in the initiation of ORT.

Latent sinoatrial conduction disturbances in symptomatic patients with Wolff-Parkinson-White syndrome

Sinoatrial conduction abnormalities were studied in fourteen patients with Wolff-Parkinson-White (WPW) syndrome and frequent attacks of supraventricular paroxysmal tachycardia. Sinoatrial conduction time (SACT), obtained by the method of constant atrial pacing, was prolonged in all but two patients. The mean value was 277 +/- 56 ms (mean +/- SD). SACT was measured in the same way in sixteen patients without signs of pre-excitation or sinoatrial disease; SACT was significantly shorter (p less than 0.001) than in the WPW group of patients. The prolongation of SACT in patients with WPW syndrome was confirmed by measuring SACT by the alternative method of programmed atrial stimulation. SACT was found to be prolonged in eight patients (mean +/- SD = 239 +/- 47 ms). Whether our results should be attributed to WPW syndrome or frequent supraventricular tachycardias--both being a characteristic feature of our patients--remains uncertain. The results of this study, however, indicate that in symptomatic patients with WPW syndrome and frequent episodes of supraventricular tachycardia, sinoatrial conduction is frequently impaired. Slackening of the sinoatrial conduction is a possible predisposing factor for initiation of tachycardias in the WPW syndrome.