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Electrophysiological characteristics of epicardial to endocardial breakthrough in intractable cavotricuspid isthmus‐dependent atrial flutter
Author(s) -
Su Chen,
Xue Yumei,
Li Teng,
Liu Menghui,
Liu Yang,
Deng Hai,
Li Jie,
Jiang Jingzhou,
Ma Yuedong,
Feng Chong,
Liu Jun,
Tang Anli,
Dong Yugang,
He Jiangui,
Wang Lichun
Publication year - 2021
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.14164
Subject(s) - medicine , atrial flutter , atrial tachycardia , ablation , cardiology , coronary sinus , catheter ablation , tachycardia , electrophysiology study
Background Epicardial to endocardial breakthrough (EEB) exists widely in atrial arrhythmia and is a cause for intractable cavotricuspid isthmus (CTI)‐dependent atrial flutter (AFL). This study aimed to investigate the electrophysiological features of EEB in EEB‐related CTI dependent AFL. Methods Six patients with EEB‐related CTI‐dependent AFL were identified among 142 consecutive patients who underwent CTI‐dependent AFL catheter ablation with an ultra‐high‐density, high‐resolution mapping system in three institutions. Activation maps and ablation procedure were analyzed. Results A total of seven EEBs were found in six patients. Four EEBs (including three at the right atrial septum and one in paraseptal isthmus) were recorded in three patients during tachycardia. The other three EEBs were identified at the inferolateral right atrium (RA) during pacing from the coronary sinus. The conduction characteristics through the EEB‐mediated structures were evaluated in three patients. Two patients only showed unidirectional conduction. Activation maps indicated that CTI‐dependent AFL with EEB at the atrial septum was actually bi‐atrial macro‐reentrant atrial tachycardia (BiAT). Intensive ablation at the central isthmus could block CTI bidirectionally in four cases. However, ablation targeted at the inferolateral RA EEB was required in two cases. Meanwhile, local potentials at the EEB location gradually split into two components with a change in activation sequence. Conclusions EEB is an underlying cause for intractable CTI‐dependent AFL. EEB‐mediated structure might show unidirectional conduction. CTI‐dependent AFL with EEB at the atrial septum may represent BiAT. Intensive ablation targeting the central isthmus or EEB at the inferolateral RA could block the CTI bidirectionally.