Inclusion Criteria:  Participant is willing and able to give informed consent for participation in the trial. Male or Female. Aged 18 years or above. History of paroxysmal and persistent AF. Dual-chamber pacemaker, Implantable cardioverter defibrillator (ICD) or cardiac resynchronisation therapy (CRT) device with a functioning atrial lead, able to record electrograms and remote monitoring.  Exclusion Criteria:  Diagnosis of permanent AF. Contra-indications for implantable cardiac monitor. Unable to comply with the follow-up schedule.