Reappraisal of Atrial Fibrillation: Interaction Between HyperCoagulability, Electrical Remodeling, and Vascular Destabilisation in the Progression of Atrial Fibrillation

Inclusion Criteria: * New onset or history of paroxysmal, self-terminating AF documented as: * AF on ECG or Holter-recording or loop recorder * Subclinical AF detected in implantable cardiac devices (atrial read \> 190 beats per minute, lasting \> 6 minutes). * Prior history of self-terminating AF is allowed; * Able and willing to sign informed consent for the registry; * Able and willing to undergo implantation of an implantable loop recorder (in patients without a CIED); * In patients already on oral anticoagulation drugs, the following inclusion criteria need to be met (to allow for safe temporary interruption of anti-thrombotic treatment for coagulation phenotyping): * CHA2DS2-VASc score ≤5 (history of Congestive heart failure, Hypertension, Age ≥ 75 years (doubled), Diabetes mellitus,Stroke/transient ischemic attack (doubled), Vascular disease, Age 65-75 years, female Sex); * No other indication for oral anticoagulation (e.g. mechanical valve prosthesis); * Patient is willing to temporarily stop oral anticoagulation drugs (OAC). Exclusion Criteria: * Non-self-terminating, persistent AF; * Deemed unsuitable or not willing to undergo implantation of loop recorder (in patients without a CIED); * Refusing to temporarily stop OAC for coagulation phenotyping (in patients already on OAC before inclusion in this study); * On waiting list for pulmonary vein isolation or expected to be placed on waiting list within one year; * Expected to start with amiodarone; * Pregnancy; * Life expectancy of less than 2.5 years.