Reappraisal of Atrial Fibrillation: RACE-V - Work Package 5

Inclusion Criteria: * Age \> 18 years; * Undergoing first elective open chest cardiac surgery or surgical ablation for atrial fibrillation; * Able and willing to sign informed consent for the registry; * Able and willing to undergo implantation of implantable loop recorder (unless the patients has a pacemaker or implantable cardioverter-defibrillator (ICD) with atrial leads) Exclusion Criteria: * • Deemed unsuitable or not willing to undergo implantation of implantable loop recorder or attend follow-up visits. * Pregnancy. * Life expectancy of less than 2.5 years. * History of prior cardiac surgery or ablation for atrial fibrillation.