Comparison of initial LA patterns as the road to successful endocardial box lesion ablation

Atrial fibrillation (AF) is the most common arrhythmia in the population. Still there is no unity in understanding of mechanisms and their influence on catheter ablation results. In our study we tried to evaluate accurate initial quantitative indicators of electromechanical remodeling that can border patients from expected good to expected poor results of catheter ablation. We performed electroanatomical mapping and ablation procedures in 94 patient (45 female) in 2012 with 3-year follow-up period. The target points were left atria surface area, complex fragmentation atrial electrograms (CFAE) duration and surface area. We investigated primary procedure efficacy and initial preoperative patterns of patients in sinus rhythm after 3-year follow-up. Patients with paroxysmal AF had about 3-4 such areas with the median duration of fragmentation 84,5msec and area 10.4cm². In persistent AF were 5-6 zones, duration of 149 msec and area 22.95cm². In long standing (LS) persistent AF 6-9 zones with duration up to 200 msec and area close to 30cm². General efficacy of radiofrequency ablation (RFA) in paroxysmal group was 58,8%, in persistent 33.3% and in LS persistent 12.9% according to Kaplan-Meyer curve with p=0.001. Retrospectively we found that every index in AF recurrence group was 1,5-2 times higher than its equivalent in sinus group. LA surface area was 131.8cm² vs 103.7cm² respectively. Median CFAE duration in AF patients was 157msec and 87.5msec in sinus patients. The principal index of CFAE square area was 2,5 times bigger (24.6cm² vs 10.3cm² relatively). We concluded that parameters of mechanical (LA volume and surface area) and electrical (CFAE duration and surface area) remodeling have to be defining in tactics and prognosis of catheter ablation in different types of AF. In order to achieve higher efficacy we advise to use stepwise tactic.