Comparison between immediately and next day post RF ablation MRI in patients with atrial fibrillation

Background Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting more than 5 million people in North America and Europe. Radio-frequency ablation (RFA) is effective in symptomatic, drug refractory AF. Reported success rates of the procedure vary significantly with AF recurrences ranging from 25-40%. The transmural extent of left atrial (LA) wall injury is difficult to assess with conventional electro-physiological (EP) measurements. Late gadolinium enhancement (LGE) and double inversion recovery T2-weighted TSE (DIR-T2w-TSE) and HASTE have been proposed to evaluate acute LA wall injury. In this study, we examine the evolution of acute (< 30 hours after RFA) atrial lesions in LGE and DIR-T2w-TSE MRI with time after the procedure. The main goals of this project are to study changes in acute lesion appearance with time after RF ablation and to determine the time interval after ablation when MRI achieves the best visibility of acute LA lesions.