Role of Magnetic Resonance Imaging of Atrial Fibrosis in Atrial Fibrillation Ablation.

Atrial fibrillation (AF) likely involves a complex interplay between triggering activity, usually from pulmonary vein foci, and maintenance of the arrhythmia by an arrhythmogenic substrate. Both components of AF, triggers and substrate have been linked to atrial fibrosis and attendant changes in atrial electrophysiology. Recently, there has been a growing use of imaging modalities, particularly cardiac magnetic resonance (CMR), to quantify the burden of atrial fibrosis and scar in patients either undergoing AF ablation, or who have recently had the procedure. How to use the CMR derived data is still an open area of investigation. The aim of this article is to summarise what is known as atrial fibrosis, as assessed by traditional catheter-based techniques and newer imaging approaches, and to report on novel efforts from our group to advance the use of CMR in AF ablation patients.