PREDICTORS OF RECURRENT ATRIOVENTRICULAR NODAL REENTRY AFTER SELECTIVE SLOW PATHWAY ABLATION

Although radiofrequency catheter ablation of the slow atrioventricular (AV) nodal pathway is highly effective for the management of AV nodal reentrant tachycardia (AVNRT), this arrhythmia may recur in some patients after an ablation procedure that initially renders AVNRT noninducible. A retrospective study examined the factors that are associated with the recurrence of AVNRT after selective radiofrequency catheter ablation of the slow pathway. Patients were included in the study if they had initially inducible, typical slow-fast AVNRT that was noninducible at the end of the ablation session. Selective ablation of the slow pathway was performed using radiofrequency energy applied along the tricuspid annulus near the coronary sinus ostium. AVNRT recurred after initially successful slow pathway ablation in 10 of 136 patients (7.4%) over a mean follow-up period of 20.1 +/- 5.0 months; the time to recurrence ranged from 1 to 411 days. Despite the absence of inducible AVNRT, dual anterograde AV nodal conduction properties persisted after slow pathway ablation in 10 patients. AVNRT recurred in 4 of 10 patients who had evidence of residual slow pathway conduction compared with only 6 of 126 who had no residual slow pathway conduction (p = 0.003). All patients with persistent slow pathway conduction and recurrent AVNRT also had residual AV nodal echo beats. AVNRT recurred in 3 of 6 patients without accelerated junctional tachycardia during radiofrequency application compared with only 7 of 109 with accelerated junctional tachycardia (p = 0.003). Thus, AVNRT infrequently recurs after successful selective radiofrequency ablation of the slow pathway. The presence of residual slow pathway conduction and AV nodal echo beats after ablation is associated with an increased risk of recurrent AVNRT.