[Comparison of the effectiveness of pulmonary veins isolation vs linear radiofrequency ablation in paroxysmal atrial fibrillation patients using either mathematical scanning or clinical approach].

AIM

to compare clinical results of linear ablation vs. PVI approach in patients with paroxysmal AF and to estimate theoretical probability of 4-waves re-entry to eliminate as a results of the both ablative techniques formatting by means left atrial geometry two-dimensional mathematical modeling.

MATERIAL AND METHODS

Clinical phase. 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-antiarrhythmic drugs (AAD)-matched groups. The first group consisted of 10 pts (3 women, mean age - 51,1±11,9, 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, mean age - 51,1±12,9, history of arrhythmia- 3,1±1,1 years) in whom ablation strategy consisted of wide-area circumferential lines application around pulmonary veins, combined to roof line and mitral isthmus RFA using three-dimensional mapping system. Mathematical phase. As the first step numeric reconstruction of the autowave process in excitable tissues of the left atrium and the simulation of AF was performed. Fitzhugh-Nagumo equation was used for simulation to enabled us to take into account the electrical inhomogeneity of the atria (pulmonary vein ostia). A special scanning method was used for calculating characteristics of autowave processes in a two-dimensional mathematical model of the atrium. As the second step simulation of circular (corresponding to LASSO approach) and linear ablation (corresponding to 3D approach) was performed.

RESULTS

Clinical phase. There were no complications associated with RFA. 7 pts of the first group vs 4 pts of the second subgroup had early recurrences of arrhythmia. AAD free sinus rhythm incidence in the first/second groups was 80%/20% at 12 months respectively (p=0,003). Mathematical phase. While circular LASSO-like ablation pattern was used, there was no elimination of 4-waves re-entry turning around the pulmonary veins ostia and vortex waves caused by them in a distributed two-dimensional atrial medium after time period equal to the re-entry period. Thus, the circular ablation formatting does not affect peripulmonary veins re-entry and, therefore, does not suppress AF. In contrast, linear ablation patterns suppress arrhythmias caused by 4-waves re-entry in two-dimensional mathematical modeling of the left atrium.

CONCLUSION

Mathematical approach using linear ablation to simulate suppressed 4-waves re-entry more effectively comparing to PVI only. Clinical results are consistent with ablation formatting data obtained by means of 4-waves re-entry simulation in a two-dimensional mathematical modeling of the left atrium.