Abstract 4136413: AV Junctional Ablation in the Era of Conduction System Pacing: Just Rate Control or also Rhythm Control?

Background: Rate and rhythm controlling therapy in patients with atrial fibrillation (AF) are theoretical concepts, however, in clinical practice there is a substantial overlap between these strategies. AV junctional (AVJ) ablation is the ultimate form of rate control; however, it may result in rhythm control as well. Hypothesis: We hypothesize that individuals that underwent AVJ ablation for AF have a decrease in their AF burden after the procedure. Goals: The purpose of our study was to determine the outcome of AVJ ablation in patients with AF, in respect to atrial rhythm and AV synchrony. Methods: Retrospective review of AF patients that underwent AVJ ablation with prior or de novo conduction system pacing (CSP) lead. Included were only patients with a cardiac monitor/device allowing assessment of AF burden prior to AVJ ablation. Results: Thirty-six patients were identified, age 74±5 years, 14 male (39%), 15 paroxysmal AF (42%), 10 persistent AF (28%), 11 longstanding persistent AF (31%). 25/33 patients (76%) had a history of AF ablation. All patients underwent implantation of, or had a prior, CSP lead [His bundle pacing n=11 (31%), LBBAP n=25 (69%)]. The heart rate decreased from 89±28 bpm pre procedure to 78±7 bpm post-AVJ ablation, p=0.01. The spontaneously conducted QRS complex prior to AVJ ablation was 116±34 ms and the QRS during CSP after AVJ ablation was 129±25 ms, p=0.02. In the entire population, AVJ ablation resulted in a reduction of AF burden from 69±40% to 48±49%, p=0.005. Of those with persistent and longstanding persistent atrial fibrillation, 5/21 patients (24%) restored normal sinus rhythm without other intervention following AVJ ablation. Of those patients that spontaneous restored normal sinus rhythm, 3/5 had prior ablations (60%). During a follow-up of 703±524 days, LV EF improved from 42±16% to 47±13%, p=0.01 . Conclusion: Although AVJ ablation is the ultimate form of rate controlling therapy, in the era of CSP it may also result in better rhythm control in a substantial number of patients. Therefore, implantation of an atrial lead and avoidance of placing the CSP lead in the atrial channel may be advisable to assure AV synchrony.