FibriCheck Data Registry

Inclusion Criteria: * At least 18 years old * Access to a smartphone to perform daily measurements * Ability to understand Dutch * Atrial Fibrillation diagnosis OR one of the following: * CHA2DS2-VASc score ≥2 (male) or ≥3 (female) * Underwent elective cardiac surgery * Known with: * Chronic obstructive pulmonary disease * Obstructive sleep apnea * Heart Failure * Hypertension * Previous stroke or transient ischaemic attack * Having palpitations and/or racing heart as symptoms * Other arrhythmia such as atrial flutter, premature atrial contractions (PAC), premature ventricular contractions (PVC) Exclusion Criteria: * Individuals which are currently in follow-up with their physician, using the FibriCheck application * Individuals with unnaturally coloured fingers (i.e. tattoos, ink); this may weaken the signal and may interfere with the effectiveness of the device * Persons with conditions causing tremors or the inability to hold their hand still for at least 60 seconds (e.g. Parkinson or dementia) as, in this case, the device may not be able to accurately process a measurement * Persons with reduced blood flow in the fingertips (e.g. perniosis or severe callus formation) as the device may not be able to detect the intensity variations induced by the blood flow * Persons that have a disability to perform the measurements according to the instructions for use * Persons with cardiac pacemakers, implantable cardioverter-defibrillators, or other implanted electronic devices as these can control the natural heart rhythm