Pulmonary veins isolation vs linear radiofrequency ablation assessment in paroxysmal atrial fibrillation patients using either mathematical scanning or clinical approach

Abstract

Aim: 1) To compare clinical results of linear ablation vs. PVI approach in patients with paroxysmal AF, and 2) to estimate theoretical probability of 4-waves re-entry to eliminate as a results of simulation the both ablative techniques in 2D mathematical modeling of left atrium (LA). Material and methods: Study was conducted on 20 pts (6 women, 51.4±13.6 years of age) with paroxysmal AF underwent index RFA. All pts were divided into two age-sex-arrhythmia history duration as well as antiarrhythmic drugs (AAD)-matched groups. The first group consisted of 10 pts (3 women, 51.1±11.9 years of age, history of arrhythmia – 3.2±1.2 years) in whom ablation strategy consisted of PVI using LASSO technique. The second group concluded of 10 pts (3 women, 51.1±12.9 years of age, history of arrhythmia – 3.1±1.1 years) in whom ablation strategy consisted of circumferential ablation combined with roof line and mitral isthmus modification (3D approach). As the first step numeric reconstruction of the autowave process in excitable tissues of the LA and the simulation of AF was performed. Fitzhugh-Nagumo equation was used for simulation of electrical inhomogeneity of the atria (PV ostia). A special scanning method was used for calculating characteristics of autowave processes in a 2D mathematical model of the LA. As the second step simulation of circular (corresponding to LASSO approach) and linear ablation (corresponding to 3D approach) was performed. Results: 7 pts of the first group vs 4 pts of the second group had early recurrences of arrhythmia. AAD free effectiveness in the first/second groups was 80%/20% at 12 months respectively (p=0,003). There was no elimination of 4-waves re-entry turning around the PVs and vortex waves caused by them in a distributed 2D atrial medium after the time period equaling to re-entry period while circular LASSO-like ablation pattern was used. In contrast, linear ablation patterns suppress arrhythmias caused by 4-waves re-entry in 2D mathematical modeling of the LA. Conclusion: Mathematical scanning approach using linear ablation to simulate clinical impact suppressed 4-waves re-entry more effectively comparing to PVI-only modeling. Our clinical results are consistent with ablation formatting data obtained by means of 4-waves re-entry simulation in 2D mathematical modeling of the LA.