Subclinical Atrial Fibrillation Detection and Relevance

Pyotr Platonov
Lund University


Abstract

Subclinical atrial fibrillation (AF) is commonly referred to the short runs of arrhythmia, which is detected by implantable devices and not associated with distinct symptoms. While commonly fulfilling conventional criteria for AF in regard to the duration of episodes that exceed 30 seconds, there is an important gap in evidence as to the best management strategy and whether or not these episodes are sufficient to motivate administration of oral anticoagulant therapy (OAC). Current AF management recommendations are based on the arrhythmia diagnosis established using conventional body surface ECG. However, for the vast majority of patients with the device-detected atrial high-rate episodes ECG confirmation of the AF diagnosis is lacking. Duration of the device-detected subclinical AF has been shown to be associated with the risk of thromboembolic events and is strongly dependent on the clinical background and the presence of cardiovascular comorbidities. While there is a compelling evidence of the benefit of OAC therapy for patients with device-detected subclinical AF exceeding 24 hours in duration, the data from observational studies are controversial in regard to the episodes of shorter duration. Several randomized clinical trials are currently on the way in order to close the evidence gap.