Electrophysiological characteristics of epicardial breakthrough during catheter ablation of perimitral atrial flutter

Chheng Chhay; Chu-Yu Hsu; Shih-Lin Chang; Yenn-Jiang Lin; Li-Wei Lo; Yu-Feng Hu; Fa-Po Chung; Ting-Yung Chang; Chin-Yu Lin; Yuan Hung; Chih-Min Liu; Ling Kuo; Shin-Huei Liu; Lia Ahli; Ming-Jen Kuo; Wen-Han Cheng; Pei-Heng Kao; Wei-Tso Chen; Thien Chuong-Nguyen Khac; Wei-Shiang Lin; Shih-Ann Chen

doi:10.3389/fcvm.2022.1030916

Electrophysiological characteristics of epicardial breakthrough during catheter ablation of perimitral atrial flutter

Front Cardiovasc Med. 2022 Nov 17:9:1030916. doi: 10.3389/fcvm.2022.1030916. eCollection 2022.

Authors

Chheng Chhay^{1

2}, Chu-Yu Hsu^{1

3

4}, Shih-Lin Chang^{1

5

6}, Yenn-Jiang Lin^{1

5

6}, Li-Wei Lo^{1

5

6}, Yu-Feng Hu^{1

5

6}, Fa-Po Chung^{1

5

6}, Ting-Yung Chang^{1

5

6}, Chin-Yu Lin^{1

5

6}, Yuan Hung⁴, Chih-Min Liu^{1

5

6}, Ling Kuo^{1

5

6}, Shin-Huei Liu^{1

5

6}, Lia Ahli¹, Ming-Jen Kuo^{1

5

6}, Wen-Han Cheng^{1

5

6}, Pei-Heng Kao¹, Wei-Tso Chen¹, Thien Chuong-Nguyen Khac¹, Wei-Shiang Lin⁴, Shih-Ann Chen^{1

5

6

7}

Affiliations

¹ Heart Rhythm Center and Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
² Cardiovascular Department, Faculty of Medicine, University of Health Sciences, Phnom Penh, Cambodia.
³ Division of Cardiology, Department of Internal Medicine, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan.
⁴ Division of Cardiology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
⁵ Faculty of Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁶ Cardiovascular Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁷ Taichung Veterans General Hospital, Taichung, Taiwan.

Abstract

Introduction: Unsuccessful endocardial ablation for perimitral atrial flutter (AFL) could be attributed by the epicardial bridging.

Objective: This study aimed to investigate the electrophysiological characteristics of epicardial breakthrough during catheter ablation of perimitral AFL.

Materials and methods: This retrospective study recruited 40 patients who received successful catheter ablation of perimitral AFL from January 2016 to June 2021. The patients were divided into two groups: group 1 (n = 18) successful endocardial ablation, and group 2 (n = 22) successful epicardial ablation following unsuccessful endocardial ablation owing to incomplete mitral block or unachievable termination AFL. The local electrogram (EGM) interval of coronary sinus (CS) duration perimitral AFL was measured before catheter ablation.

Results: There was no significant difference in the baseline characteristics between the two groups. In group 2, 60% of successful epicardial ablation was performed in intra-CS ablation and 40% in VOM ethanol infusion. Group 2 patients had a longer EGM interval of distal CS than that in group 1 (CS1-2: 64.2 17.5 vs. 42.4 0.09 ms, P = 0.008, CS3-4: 57.13 19.4 vs. 43.8 7.5 ms; P = 0.001). The conduction velocity at successful site was slower in group 2 compared to group 1 (0.18 0.05 vs. 0.75 0.19 m/s, P = 0.040). In the multivariate analysis, distal EGM interval (CS1-2) was identified as independent predictor of the need of epicardial ablation with the optimal cutoff of 49 ms.

Conclusion: Longer EGM interval in distal CS during perimitral AFL was observed in perimitral AFL patients with epicardial breakthrough following endocardial-failed ablation, which may be associated with the need of epicardial ablation.

Keywords: EGM interval of distal CS; atrial fibrillation; catheter ablation; epicardial breakthrough; perimitral atrial flutter.