Prevention of iatrogenic atrial tachycardia after ablation of atrial fibrillation - A prospective randomized study comparing circumferential pulmonary vein ablation with a modified approach

Background-Circumferential pulmonary vein ablation (CPVA) is effective in curing atrial fibrillation (AF), but new-onset left atrial tachycardia ( AT) is a potential complication. We evaluated whether a modified CPVA approach including additional ablation lines on posterior wall and the mitral isthmus would reduce the incidence of AT after PV ablation. Methods and Results-A total of 560 patients (291 men, 52%; age, 56.5+/-7.3 years) entered the study; 280 were randomized to CPVA alone ( group 1) and 280 to modified CPVA ( group 2). The primary end point was freedom from AT after the procedure. In group 1, 28 patients (10%) experienced new-onset AT, and 41 (14.3%) experienced recurrent AF. In group 2, 11 patients (3.9%) experienced AT, and 36 (12.9%) had recurrent AF. Group 1 was more likely to experience AT than group 2 (P=0.005). Freedom from AF after ablation was similar in both groups (P=0.57). Among those in group 1, gap-related macroreentrant AT was documented in 23 of the 28 patients (82%), and focal AT was found in 5 (18%). In group 2, gap-related macroreentrant AT was found in 8 of the 11 patients (73%), and focal AT was seen in 3 (27%). Two patients in group 1 and 1 patient in group 2 had both AT and AF. The strongest predictor of AT was the presence of gaps (P<0.001). Conclusions-Modified CPVA is as effective as CPVA in preventing AF but is associated with a lower risk of developing incessant AT.