Catheter ablation to suppress atrial fibrillation: evolution of technique at a single center

Catheter ablation of atrial fibrillation is a rapidly evolving art. There is currently no consensus as to optimal methodology. We report a sequential experience, during which three distinct ablation techniques were utilized.

A cohort of 112 patients in whom atrial fibrillation onset was precipitated by ectopy arising solely from myocardium investing the pulmonary veins underwent catheter ablation using one of three techniques: focal (Group A); individual vein encircling (Group B); vestibule encircling (Group C). In each group, non-fluoroscopic guidance of the mapping and ablation process was provided by the tandem use of CARTO and intracardiac echocardiography.

In all groups, endocardial topography was complex, and ablation electrode-endocardial contact was often unstable. Maximal electrode temperatures were low, despite frequent echocardiographic evidence of myocardial boiling. A significant progression in the number of radiofrequency energy applications between groups A and C was observed. Although acute suppression of atrial fibrillation inducibility was observed uniformly, chronic suppression rates were significantly different: Group A = 47%; Group B; 69%; Group C = 87%.

In this non-concurrent cohort, the rate of chronic suppression of atrial fibrillation correlated with the amount of myocardium ablated or electrically isolated. Prospective data will be required to further evaluate whether "more is better."