Treatment of atrial fibrillation by catheter-based procedures.

Catheter-based procedures have been developed with a view to reproduce or improve upon the excellent results of the Maze procedure in the treatment of atrial fibrillation (AF). Linear epicardial lesions created using minimally invasive techniques, or endocardial lesions to encircle the pulmonary veins (PV) have been associated with restoration of sinus rhythm in high percentages of carefully selected patients. The tricuspid-caval isthmus interruption procedure for atrial flutter is highly successful and, in patients who have both atrial flutter and fibrillation, prevents the development of AF when combined with antiarrhythmic agents. Modification of atrioventricular (AV) nodal conduction by eliminating the posterior atrial inputs to the AV node is performed to decrease the ventricular rate and alleviate symptoms during AF without the need for permanent pacing, though may be complicated by inadvertent AV block. AV junctional ablation and permanent pacing alleviates cardiac symptoms, improves quality-of-life, and reduces the use of health care resources. Its constraints include the inescapable need for anticoagulation, loss of AV synchrony, and life-long pacemaker-dependency. The variety of methods and results among published studies strongly emphasises the importance of patient selection, and the relative importance of substrate versus trigger. Possible complications of catheter ablation for AF include systemic thromboembolism, PV stenosis, pericardial effusion, cardiac tamponade, and phrenic nerve paralysis. These remain a matter of concern and stimulate research toward the development of less complex procedures.