Predictors of the atrial fibrillation occurrence in patients with Wolff-Parkinson-White syndrome.

BACKGROUND: Atrial fibrillation (AF) in WPW syndrome occurs earlier and is more common than in the general population. AIM: To evaluate the predisposing factors for the first episode of AF in patients with WPW. METHODS: We analysed data on 930 patients (510 males, 420 females) with WPW treated in our centre during 1988-2007. AF was diagnosed in 236 patients (25% - 161 males, 75 females, aged 36 +/- 15 years). The AF group was divided into two subgroups - patients with AF and atrio-ventricular reentrant tachycardia (AVRT), and patients with AF only. The analysis included subjects' age and gender, the presence of AVRT, the number and properties of accessory pathways, left ventricular ejection fraction (LVEF) and concomitant cardiovascular diseases. RESULTS: The groups did not differ in terms of concomitant diseases and LVEF. In the whole group of patients with AF, arrhythmia occurred earlier in men than in women (34 +/- 14 vs. 40 +/- 15 years of age, p = 0.013). In the subgroup with AF and AVRT, AF was documented earlier compared to patients with AF only (34 +/- 15 vs. 41 +/- 15 years of age, p = 0.0072). AVRT was more common in patients with AF compared to those without AF (69 vs. 53%, p < 0.001). In the whole group of 930 patients, AF was observed more often in patients with overt pre-excitation compared to concealed WPW (29 vs. 12%, p < 0.001). CONCLUSIONS: In patients with WPW syndrome, AF occurs earlier in patients with AVRT compared to patients with AF and without documented AVRT, earlier in men compared to women, and is more common in patients with overt WPW.