Altered electroanatomic patterns of right ventricle in myotonic dystrophy type 1 patients

Abstract

Background: Prolongation of the atrial fibrillation cycle length (AFCL) and termination of AF during ablation have been reported. We investigate the significance of regions of maximal dominant frequency (DF) identified by spectral analysis, determining the effect of ablation at these sites located within the pulmonary veins (PV) on the fibrillatory process. Methods: Thirty-two patients undergoing AF ablation during ongoing arrhythmia were studied. Electroanatomic mapping was performed, acquiring 126 13 points/pt throughout both atria and coronary sinus (CS). At each point, 5s electrograms were obtained to determine the highest amplitude frequency on spectral analysis and construct 3D DF maps. Ablation was performed with the operator blinded to the DF maps. The effect of ablation at PVs with or without high-frequency DF sites (maximal frequencies surrounded by a decreasing frequency gradient 20%) was evaluated by determining the change in AFCL within the CS before and after isolation of each PV, and the termination of AF. Results: PV ablation was associated with an increase in AFCL (174 27 to 184 35ms; p 0.0001). While ablation at a PV harboring a DF site resulted in AFCL prolongation (180 30 to 198 40ms; p 0.0001), ablation at a PV without a DF site did not change the AFCL (169 22 to 170 22ms; p 0.4). Ablation at PVs harboring a DF site resulted in an increase in AFCL ( 5ms) within the CS in 89% with the mean increase in AFCL of 18 21ms (range 0-118ms) compared to 0.9 3.9ms (range -10 to 7ms; p 0.0001) after ablation at PVs without a DF site. The increase in AFCL with PV ablation demonstrated a strong concordance with ablation at a DF site (kappa-coefficient of 0.77). PV ablation resulted in AF termination in 14 pts; 11 at a DF site. In the remaining 3, 2 had frequent cessation of arrhythmia during mapping. Conclusion: High frequency PV activity identified by spectral analysis has an important role in maintaining AF. Ablation at these sites resulted in slowing of the fibrillatory process and termination of paroxysmal AF.