EFFECTIVENESS OF THE RADIOFREQUENCY ABLATION OF PAROXYSMAL AND PERSISTENT ATRIAL FIBRILLATION IN PATIENTS WITH ELECTROPHYSIOLOGICAL AND STRUCTURAL LEFT ATRIAL REMODELING
Aims: The purpose of this study was to determine degree of electrophysiological (EP) and structural left atrial (LA) remodeling associated with AF recurrence after radiofrequency (RF) ablation in patients (pts)with paroxysmal and persistentAF.
Methods:112pts (56.9±9.0 years) with highly symptomatic paroxysmal (80pts) and persistent (31pts)AF underwent PV and roof RF ablation. Bipolar maps (BM) were created, low voltage zones (LVZs)were defined separately as a bipolar electrogram amplitude of<0.2, 0.2-0.5, 0.51-0.75 mV, 0.75-1mV and>1 mVrespectively. The local CV through the LVZ and non-LVZ was calculated within each zone. Effective refractory periods (ERP) wereevaluatedand index heterogeneity (IGERP) was calculated.
Results: Accordingto results of BM (296±46 points) by analogy with Utah classification there were identified 4 groups: (I)minimal fibrosis with SLVZs2.8±1% in 26pts;(II) mild with SLVZs13.7±4%-25, (III) moderate with SLVs26± 4%-29, (IV) severe with SLVZs 57±19% in 28pts. LVZ sin 23% were located on the roof, in 16% in posterior wall (PW),in 10% in septal, in 5% in anterior area of the LA and in 0.9% in mitral isthmus. The local CV in LVZ< 0.2mV, 0.21-0,5mV and 0.51-0.75 was 0.38 ± 0.13m/s,0.55±0,24m/s and 0.72±0.2m/s respectively; in zones 0.76-1 mV and more then 1 mV- 1.7±0.45m/si 2± 0,58m/srespectively. IGERP in I group was 5.7±2.3, inII- 7±4, in III-15±5.2, in IV- 15.7±6.1. During the follow-up, 8.7±3.6 monthsthe rate of AF recurrence was 4.0% in I, 16% in II, 32% in III and 45% in IV group. Redo procedures were performed in 9%. 74% of patients had no recurrence of AF.
Conclusions: BM allows identifying the LVZ with pathological EF properties, the most frequent localization of which is the roof and posterior wall of the LA. The likelihood of AF recurrenceafter RFAassociated with the degree LA structural remodeling and the highest in the group of moderate and severe fibrosis.