Efficacy and Safety of Low-Power (20 W) Catheter Ablation for Typical Atrioventricular Nodal Reentrant Tachycardia: A Prospective Multicenter Study

Background Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common supraventricular tachycardia. Although catheter ablation is the definitive treatment, atrioventricular (AV) block requiring permanent pacemaker implantation remains a major safety concern. Objective To evaluate the efficacy and safety of a low-power (20 W) slow pathway ablation strategy for typical AVNRT. Methods In this prospective multicenter study, 203 consecutive patients (mean age 54.4 ± 17.3 years; 59.6% women) underwent slow pathway ablation initiated at 20 W, with power escalation as needed. Variables associated with requiring higher power were analyzed using univariate logistic regression. Results Initial success at 20 W was achieved in 170 patients (83.7%); 33 patients (16.3%) required higher power. Compared with patients who achieved success at 20 W, those requiring higher power were younger and had higher pre-ablation heart rates. On univariate analysis, younger age (odds ratio [OR] 0.66 per 10-year increase, 95% confidence interval [CI] 0.54–0.83; p  < 0.001) and higher pre-ablation heart rate (OR 1.88 per 10-bpm increase, 95% CI 1.30–2.73; p  < 0.001) were associated with the need for higher power. Transient AV block occurred in 1.9% of patients, and no cases of permanent AV block or pacemaker implantation were observed. During 18.3 ± 4.1 months of follow-up, recurrence occurred in two patients (0.9%). Conclusion An initial 20 W ablation strategy provides high efficacy with excellent safety and no permanent AV block. Younger age and a higher baseline heart rate predicted the need for power escalation, supporting a stepwise low-to-high power approach for AVNRT ablation.