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 univariable and multivariable logistic regression. Results Initial success at 20 W was achieved in 170 patients (83.7%); 33 patients (16.3%) required higher power, with an overall acute success rate of 99.5%. Compared with patients who achieved success at 20 W, those requiring higher power were younger and had higher pre-ablation heart rates. On univariable 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 (0%, 95% CI 0%–1.8%) 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 a favorable safety profile and no permanent AV block observed in this cohort. Younger age and a higher baseline heart rate predicted the need for power escalation, supporting an initial low-power approach for AVNRT ablation.