Catheter ablation for atrial fibrillation.

Catheter ablation for atrial fibrillation is based upon the critical mass of fibrillation hypothesis and aims to compartmentalize the atria by the creation of linear lesions, thereby reducing the amount of contiguous myocardium available for the propagation of multiple activation wavefronts. Early attempts at creating right atrial linear lesions with conventional catheter tip technology to treat patients with chronic and paroxysmal atrial fibrillation yielded disappointing results. Although more efficacious, the creation of extensive left atrial lesions has been associated with a high rate of thromboembolic stroke despite the administration of heparin and use of temperature feedback to control radiofrequency energy. Approaches to reduce the risk of stroke include: the creation of more continuous and effective right atrial lesions with linear array catheter technology and thereby reduce the requirement for left atrial ablation; the assessment of adjuvant pharmacological agents to inhibit platelet aggregation; guidance of radiofrequency energy delivery by intracardiac echo; assessment of transvenous cryotherapy as an alternative to radiofrequency energy in order to reduce endocardial disruption; and development of minimally invasive surgical approaches to left atrial epicardial ablation.