Low-Voltage Zones as the Atrial Fibrillation Substrates: Relationship With Initiation, Perpetuation, and Termination

Zheng Liu; Yu Xia; Changyan Guo; Xiaofeng Li; Pihua Fang; Xiandong Yin; Xinchun Yang

doi:10.3389/fcvm.2021.705510

Low-Voltage Zones as the Atrial Fibrillation Substrates: Relationship With Initiation, Perpetuation, and Termination

Front Cardiovasc Med. 2021 Aug 2:8:705510. doi: 10.3389/fcvm.2021.705510. eCollection 2021.

Authors

Zheng Liu¹, Yu Xia², Changyan Guo³, Xiaofeng Li², Pihua Fang², Xiandong Yin¹, Xinchun Yang¹

Affiliations

¹ Heart Center, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
² State Key Laboratory of Cardiovascular Disease, Cardiac Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
³ Department of Cardiology, Xilin Gol League Central Hospital, Inner Mongolia, Xilinhot, China.

Abstract

Background: Low-voltage zones (LVZs) were usually targeted for ablation in atrial fibrillation (AF). However, its relationship with AF initiation, perpetuation, and termination remains to be studied. This study aimed to explore such relationships. Methods: A total of 126 consecutive AF patients were enrolled, including 71 patients for AF induction protocol and 55 patients for AF termination protocol. Inducible and sustainable AF were defined as induced AF lasting over 30 and 300 s, respectively. Terminable AF was defined as those that could be terminated into sinus rhythm within 1 h after ibutilide administration. Voltage mapping was performed in sinus rhythm for all patients. LVZ was quantified as the percentage of the LVZ area (LVZ%) to the left atrium surface area. Results: The rates of inducible, sustainable, and terminable AF were 29.6, 18.3, and 38.2%, respectively. Inducible AF patients had no significant difference in overall LVZ% compared with uninducible AF patients (10.2 ± 11.8 vs. 8.5 ± 12.6, p = 0.606), while sustainable and interminable AF patients had larger overall LVZ% than unsustainable (16.2 ± 11.5 vs. 0.5 ± 0.7, p < 0.001) and terminable AF patients (44.6 ± 26.4 vs. 26.3 ± 22.3, p < 0.05), respectively. The segmental LVZ distribution pattern was diverse in the different stages of AF. Segmental LVZ% difference was initially observed in the anterior wall for patients with inducible AF, and the septum was further affected in those with sustainable AF, and the roof, posterior wall, and floor were finally affected in those with interminable AF. Conclusions: The associations between LVZ with AF initiation, perpetuation, and termination were different depending on its size and distribution.

Keywords: atrial fibrillation; electroanatomic mapping; inducibility; low voltage; sustainability; termination.