RELATION BETWEEN SPONTANEOUS ATRIAL-FIBRILLATION AND ATRIAL VULNERABILITY IN PATIENTS WITH WOLFF-PARKINSON-WHITE PATTERN

An intracavitary electrophysiological study was carried out on 103 patients with Wolff‐Parkinson‐Whire (WPW), 23 symptomatic patients had documented episodes of atrial fibrillation, 54 symptomatic patients had atrioventricular reentrant tachycardias, and 26 asymptomatic. Patients were examined for the relation between spontaneous atrial fibrillation and atrial vulnerability, defined as the possibility to induce sustained (> 1 minute) episodes of atrial fibrillation with a stimulation protocol excluding atriai bursts. Atrial fibrillation induction was attempted by single and double atriai extrastimuli during pacing at two different cycle lengths and incremental atrial pacing. Sustained atrial fibrillation was induced in 65% of the patients with spontaneous atrial fibrillation, and in 13% of the symptomatic patients with documented episodes of atrioventricular reentrant tachycardias and in 15% of the asymptomatic patients (P < 0.0005). Atrial vulnerability was higher in patients with spontaneous atrial fibrillation than in patients without this arrhythmia. No significant difference was observed between symptomatic without atrial fibrillation and asymptomatic patients. Copyright © 1990, Wiley Blackwell. All rights reserved