Clinical Electrophysiology -> Atrial Fibrillation & Atrial Flutter: -> Physiology D-MP09 - Atrial Fibrillation: From Pathophysiology to Epidemiology to Treatment Options (ID 36) Moderated ePoster

D-MP09-02 - Bachman Bundle Breakthroughs Shift Following Radiofrequency Pulmonary Vein Isolation For Paroxysmal Atrial Fibrillation (paf) (ID 844)

 A. Torrelli-Diljohn: Nothing relevant to disclose.


Background: Inter atrial activation (IAC) is carried mainly via Bachman Bundle (BB). BB can be damaged during WACA. We describe the changes in Left Atrial (LA) breakthrough (bk) post WACA.
Objective: To assess the effects of WACA on IAC.
Methods: 31 unmedicated patients (pts) (age 65 ± 10 years, 30 males) with Paroxysmal Atrial Fibrillation underwent radiofrequency WACA. 3D-LA mapping was performed before and after ablation. Areas of bk were documented at BB, Fossa Ovalis (FO) and Coronary Sinus (CS). These regions were localized using Intravascular Echocardiography. Bks were identified using 5 ms interval isochronal windows. A secondary bk was deemed present if it occurred within 10 ms from first. Distance between the ablation line and initial bk was measured on the map.
Results: Pre-procedure LA bk was BB in 22 pts, FO in 9 pts. Post-ablation 16 BB bk shifted: 11 pts to FO and 5 pts developed dual bk (BB and CS). 2 pts shifted from FO to BB. The post-ablation bk was present pre-ablation with a delay of 13-18 ms following primary bk. The distance between the ablation line and initial LA bk was closer in the group with major post-ablation shifts (4.3 ± 5.4 mm) when compare with unchanged bk (12.1 ± 5.9 mm ;p<0.01).
Conclusion: BB damage delays IAC connections in a large percentage of patients post PVI, and shifts initial bk to a secondary site. The secondary sites were already present pre-ablation in keeping with physiological multi IA connections. Bk shifts may change LA propagation predisposing to future arrhythmias.