The goal of this randomized open-label clinical trial is to evaluate two different strategies for the treatment of recurrent atrial fibrillation (AF) after AF ablation. Patients who have symptomatic, drug-refractory recurrence of AF will be randomized to either a redo AF ablation vs conduction system pacing with AV node ablation. Patients will need to have undergone at least 1 prior AF ablation to be considered eligible for the study. The current trial is a vanguard study of 16 patients and will determine the feasibility of enrolment, compare changes in quality of life, and inform the design of the definitive REDO AF trial.

Recurrence rates after atrial fibrillation (AF) ablation procedures are high at approximately 50% at 18 months and are associated with procedural risk as well as with significant costs. There is limited guidance on how best to treat those who recur post AF ablation. The combination of pacemaker implantation and atrioventricular node ablation (AVNA), so-called "pace-and-ablate" strategy, is an alternative treatment in patients who are at high risk of AF recurrence, especially since the recent introduction of left bundle branch pacing (LBBP). LBBP is a type of pacing strategy that captures the intrinsic conduction system and preserves normal physiological ventricular activation. The REDO-AF Trial will compare a strategy of pace-and-ablate therapy with LBBP + AVNA as compared to a strategy of redo AF ablation in medically refractory patients presenting with recurrent symptomatic AF post AF ablation. We hypothesize that a pace-and-ablate strategy will result in reduction in cardiovascular hospitalizations, procedural complications and an improvement in quality of life (QOL). The definitive research question of the REDO-AF trial is: Can a strategy of LBBP combined with AVNA in patients with recurrent, symptomatic, drug-refractory AF after previous AF ablation(s), who remain at high risk of recurrence, lead to a reduction in cardiovascular hospitalizations, reduction in procedure or device-related complications, and a greater improvement in QOL as compared to a subsequent (redo) AF ablation.

Inclusion Criteria:

• One or more prior left atrial (LA) ablation procedure(s) for AF
• Symptomatic AF/atypical atrial flutter/atrial tachycardia with failure of or intolerance to medical rate or rhythm control therapy, that is detected at >2 months post most recent LA ablation procedure
• Either a LA volume index on any prior echo of >= 45ml/m2 or LA diameter >= 50mm OR a HATCH score >=2 (where 1 point is given for each for hypertension, Age>75, COPD, and 2 points for each of stroke/TIA, or HF (defined as signs or symptoms of pulmonary edema and may include HFrEF or HFpEF)
• Be considered suitable for both treatment strategies of redo ablation and pacemaker and AV node ablation
• Willingness to participate, complete the QOL questionnaires and ability to sign informed consent

Exclusion Criteria:

• Severe valvular disease defined by echo criteria
• Myocardial infarction, stroke, or coronary revascularization within the previous 3 months
• LVEF <40% or need for an ICD
• Life expectancy <24 months
• Lack of capacity to consent