Assessment of Left Atrial Fibrosis by Late Gadolinium Enhancement Magnetic Resonance Imaging: Methodology and Clinical Implications.

Recently, studies using late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) to identify structural changes of atrial tissue have contributed significantly to understanding the pathophysiology and progression of atrial fibrillation (AF). Moreover, imaging of atrial fibrosis using MRI has evolved to be a tool to improve clinical outcome of AF ablation procedures by allowing a patient-specific individualized management approach. LGE-MRI has been shown to predict AF ablation outcome based on pre-procedural imaging to define the extent of atrial fibrosis. The results of the ongoing DECAAF II (Delayed-Enhancement MRI Determinant of Successful Radiofrequency Catheter Ablation of Atrial Fibrillation) trial might extend ablation strategies from pulmonary vein isolation alone to a substrate-based approach. Furthermore, an improved understanding of the underlying mechanisms of atrial structural remodeling is crucial in order to reduce the occurrence of AF-associated complications (e.g., ischemic stroke and heart failure). This review article provides current methodology of atrial fibrosis imaging using LGE-MRI and delineates actual clinical implications and future directions for this imaging approach.