AV Junction Ablation or Optimal Medical Treatment in PatiEnts With Cardiac Resynchronization Therapy and Permanent Atrial Fibrillation

Who May Qualify: - Treatment with CRT using either a biventricular pacemaker/defibrillator or conduction system pacemaker (\>6 months) - Diagnosis of AF and classified as: permanent AF or recurrent persistent AF, requiring emergency visits and/or hospitalizations (at least one in recent year) - Optimized HF medical treatment and rate control medication - BiVP% + ventricular premature complex (VPC%) \<99% and \>85% during the minimum period of 1 month while already on optimum medical therapy (applicable only for patients with permanent AF) - Age \>18 and \<85 years - Signed willing to sign a consent form Who Should NOT Join This Trial: - myocardial infarction (MI) or coronary artery bypass graft (CABG) \<3 months - Technical failure of the CRT system - Intentional preference for spontaneous AV conduction - Expected survival \<1 year - Other significant comorbidities and/or conditions that interfere with the proper conduction of the trial - Dementia as assessed by mini-mental test (\<23 points) Always talk to your doctor about whether this trial is right for you.