TRANSESOPHAGEAL ELECTROPHYSIOLOGICAL STUD Y IN THE MEDIUM-TERM FOLLOW-UP AFTER RADIOFREQUENCY ABLATION OF INTRANODAL REENTRANT TACHYCARDIAS

The aim of this prospective study was to assess the medium term result s of radiofrequency ablation of intranodal tachycardias by transoesoph ageal stimulation and recordings. Transoesophageal stimulation was per formed on average 9 months after ablation. The anterograde Wenckebach point, the presence of dual nodal conduction and inducibility of nodal tachycardias were determined under basal conditions and after isoprot erenol. The follow-up period after ablation was 16.1 +/- 10.2 months. At the time of the oesophageal investigation 25 patients were asymptom atic and 9 had a recurrence of palpitations. The investigation was car ried out without complications in all patients and lasted 34.8 +/- 14 minutes. The anterograde Wenckebach point was 340 +/- 78.2 ms and was unchanged compared with the value recorded by endocavitary left atrial stimulation before ablation (332 +/- 63.2 ms). Dual nodal conduction was observed in 19 patients. Nodal tachycardia was inducible in only 2 of the 5 patients with palpitations. Of the asymptomatic patients, 3 had inducible nodal tachycardias after isoproterenol. The authors conc lude that oesophageal electrophysiological studies are a simple means of assessing the medium-term results of radiofrequency ablation of int ranodal tachycardias. In those patients with a recurrence of symptoms but without documented arrythmias, failure of radiofrequency ablation may be identified. In addition, the possibility of inducing nodal tach ycardias in asymptomatic patients may be detected.