Apple Watch-led Surveillance of AF Recurrence After Catheter Ablation

Inclusion Criteria: * Referred for first AFCA procedure by a Consultant electrophysiologist. * Paroxysmal or persistent AF captured on ECG but not in continuous AF for more than 3 years. (Paroxysmal AF is defined as an episode of AF that terminates spontaneously or with intervention within 7 days of onset. Persistent AF will be defined as any continuous episode lasting longer than 7 days or requiring intervention to restore sinus rhythm after this time.) * At least one episode of AF must have been documented by ECG or Holter within 12 months of inclusion in the study. * Continuous anticoagulation with warfarin (INR 2-3), low molecular weight heparin, or a novel oral anticoagulant (dabigatran, apixaban, rivaroxaban, edoxaban) for ≥4 weeks prior to the ablation; or a TEE that excludes LA thrombus ≤48 hours before ablation. * Access to a smartphone with Apple-operating system (OS) within their household for syncing with their watch. * Participants must be able and willing to provide written informed consent Exclusion Criteria: * Patients with permanent AF. Permanent AF is defined as chronic, persisting AF (typically more than 1 year) for which cardioversion (pharmacologic or electrical) has failed or will never be attempted. * Patients with AF felt to be secondary to an obvious reversible cause. * Patients who are, or may potentially be pregnant. * Any cardiac implantable electronic device in situ or expected to undergo implantation in the next 12 months. * Previous left atrial (LA) ablation or LA surgery * Pre-existing pulmonary vein stenosis or PV stent * Pre-existing hemi-diaphragmatic paralysis * Contraindication to anticoagulation or radiocontrast materials * Acute coronary syndrome within 4 weeks as defined by ECG ST segment depression or prominent T-wave inversion and/or positive biomarkers of necrosis (e.g. troponin) in the absence of ST-segment elevation and in an appropriate clinical setting (chest discomfort or angina equivalent). * Cardiac surgery, angioplasty, or cerebrovascular accident within 4 weeks prior to enrolment. * Life expectancy less than 1 year