Surgical treatment of atrial fibrillation: a review.

The optimal treatment of atrial fibrillation (AF) depends upon a proper understanding of the electrophysiological basis of its clinical manifestations. Whether AF is continuous (persistent) or intermittent (paroxysmal) depends on variable underlying electrophysiology and determines the choice of interventional treatment. The initiation of intermittent AF requires a "trigger", often, though not always, located near the orifices of pulmonary veins. In contrast, continuous AF does not need a "trigger" to be re-induced repetitively and does not depend on the pulmonary veins or other abnormal automatic foci for its induction or perpetuation. Simple pulmonary vein encircling confines the trigger to the pulmonary veins and, if expertly performed, will cure the majority of patients with intermittent AF. On the other hand, continuous AF requires a Maze procedure or variant thereof to eliminate atrial macro-reentry while allowing sinus rhythm to activate the entire atrial myocardium and preserve atrial transport function. This article reviews the development of the surgical Maze procedure and its implications for the treatment of AF by percutaneous intracardiac or epicardial, minimally invasive techniques. High-intensity focussed ultrasound, a new energy source generating frictional heat, appears promising in the creation of focussed transmural lesions, while preserving the integrity of coronary arterial walls.