1. INTRODUCTION
New onset atrial arrhythmia (AA), including atrial fibrillation (AF) and atrial tachycardia (AT), can occur after mitral valve repair in patients with mitral regurgitation (MR). Post-operative AF has been reported to be associated with long-term all-cause mortality.1,2However, a predictor of post-operative AA has not been fully elucidated. A previous study has shown that the post-operative aorto-mitral angle is associated with the reverse remodeling of the left atrium (LA) after a mitral valve repair.3 Consequently, we hypothesized that the post-operative aorto-mitral angle might also relate to the occurrence of post-operative AA. The purpose of the present study was to determine whether the post-operative aorto-mitral angle could predict new onset AA after mitral valve repair with mitral annuloplasty for treating MR.