Catheter Ablation -> SVT/AVNRT/WPW/AT: -> Mapping & Imaging D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-190 - Characteristics, Mechanism And Ablation Outcome Of Atrial Tachycardias After Cardiac Surgery And Concomitant Maze Procedure (ID 958)


Background: There have been few reports on the characteristics, mechanisms, and ablation outcomes of atrial tachycardias (ATs) after cardiac surgery and concomitant Maze procedures.
Objective: The purpose of this study was to investigate the mechanism and long-term outcome of ablation of ATs after Maze procedures.
Methods: We analyzed 41 consecutive patients (70.0±7.2 years old, 20 men) with ATs after cardiac surgery and a concomitant Maze procedure between 2007 and 2019.
Results: All patients had residual electrical conduction (gaps) on the Maze lines (Figure, 71 gaps, 2.0±1.3 gaps per patient). Fifty-five ATs were induced and 50 of 71 gaps (70.4%) were associated with the ATs; 23 of 50 gaps were associated with peri-mitral atrial flutters (M-AFL) and 11 of 50 gaps were associated with cavo-tricuspid isthmus dependent AFL. Regarding the pulmonary vein isolation (PVI) line, 19 of 41 patients (47.5%) had gaps on the PVI line, but only 2 gaps were associated with ATs (10.5%). Overall, the AT mechanism was related to the Maze procedure in 32 of 41 patients (78.0%). Fifty-two of 55 ATs (94.5%) were successfully ablated. There were no major complications. Twenty-seven patients (67.5%) were free from ATs during a median follow-up period of 25.5 months (IQR 6.5-44.5). Three patients (7.3%) underwent re-session of catheter ablation and were successfully ablated.
Conclusion: The ATs after cardiac surgery and a concomitant Maze procedure were mainly reentrant mechanisms, and were largely related to gaps on the Maze procedure line between the mitral valve and PVI line. Catheter ablation of these ATs seemed to be effective and safe during the long-term follow-up.