0038: Impact of accessory pathway ablation on the risk of atrial fibrillation in patients with overt conduction and patients with concealed conduction over accessory pathway

Purpose of the studyto evaluate the impact of accessory pathway (AP) ablation on the risk of subsequent atrial fibrillation (AF) of patients with a pre-excitation syndrome (PS) and patients with a normal ECG but with AV reentrant tachycardia (AVRT) over a concealed AP.Methods103 patients were studied: 93 patients, mean age 41±16 years, with a PS presented with a well or poorly-tolerated AF (group I). They were issued from a group of 905 patients (10%) with a PS (mean age 34±17 years). Ten patients, mean age 50±21, with a normal ECG in sinus rhythm and with AVRT were referred for AF (group II). They were issued from a group of 303 patients (3%) with AVRT and a normal ECG (mean age 42±18 years). Electrophysiological study was performed in control state and after isoproterenol. Patients were followed from 3 months up to 20 years.ResultsThe incidence of AF at the admission was higher in PS than in patients with concealed AP (p<0.0001). In group I, a re-entrant tachycardia was induced in 59 patients (63%). AF was induced in 65 patients (70%). In group II AF was induced in 4 patients (40%)(0.06). AP ablation was performed in 75 group I patients (81%) and 7 group II patients (70%) (NS). After a mean follow-up of 3±2 years, 17 group I patients (18%) presented AF recurrence, despite AF ablation performed in 13 of them. In patients with a PS but without AF at admission, AF occurred only in 14 patients (2%)(p<0.0001). Three group II patients (30%)(p<0.005) in whom AP ablation was performed had AF recurrence. In patients with AVRT, normal ECG and no history of AF, AF only occurred in 3% (9/293). The differences were highly significant (p<0.0001).ConclusionsAF incidence at the admission was higher in patients with a PS than in patients with concealed AP (p