Surgical treatment of atrial fibrillation with concomitant mitral valve disease: an Asian review.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in patients with mitral valve disease and is present in up to 50% of patients undergoing mitral valve surgery, contributing to increased risks of systemic embolization, anticoagulant-related hemorrhage and mortality. The Cox maze III procedure, introduced in 1987 by Dr. James Cox, was the first effective operation for AF and is recognized as the gold standard therapy for AF associated with organic heart disease. However, few surgeons have adopted the Cox maze III procedure, as it is a lengthy operation with extensive cutting, suturing and blood loss. Several groups in Asia have successfully developed less invasive approaches using a number of different energy sources to create continuous lines of ablation to replace the surgical incisions. Because high-density real-time intraoperative mapping to define the mechanisms of AF is currently not available to guide AF ablation in most surgical groups, an anatomic approach to ablation based on our understanding of the pathophysiology and empiric results is reasonable. The preoperative left atrial size and duration of AF are primary predictors of sinus conversion after the maze procedure for patients with persistent and permanent AF and mitral valve disease. The maze procedure combined with an atrial volume reduction technique may increase the sinus conversion rate. Future progress will require a better understanding of the mechanisms of AF, and minimally invasive cardiac surgery with endoscopic AF ablation needs to be explored in the Asian region.