Electrophysiological characteristics and cause analysis of ridge related reentry after catheter ablation of atrial fibrillation / 中国介入心脏病学杂志

ABSTRACT

Objective To identify the electrophysiological charateristics and cause of ridge gap related reentry after MI ablation in atrial ifbrillation patients. Methods Activation and entrainment mapping was performed in 82 redo cases for OAT recurrence in whom MI was ablated during the index produre. Once ridge gap related reentry was conifrmed, detailed mapping was performed in MI and ridge region. In addition, in 36 cases undergoing MI ablation and fulfilling criterion for bidirectional block, differential pacing was repeated at the ridge to identify a ridge gap. Results Out of 82 redo cases for OAT recurrence in whom MI was ablated during the index produre, 7 (8.5%) was found to be ridge gap related reentry. TCL was (247.9±19.2) ms, and the left atrial endocardial activation time was (145.4±17.7) ms, accounting for (58.5±3.2)%of TCL. However, wide double potential was recorded along the previous ablated MI line where PPI was (34.3±6.6) ms longer than TCL, while PPI was signiifcantly shorter at the ridge[PPI-TCL (11.4±3.9) ms, P<0.001]. Tachycardia was terminated at the ridge in 6 cases and at the corresponding site in coronary sinus in 1 case. No recurrence was found during follow-up for (11.1±4.5) months. In addition, in 36 patients undergoing MI ablation in whom criterion of bi-directional block was fuliflled, conduction gap located at the ridge was found in 5 (13.9%) cases. Conclusions MI ridge gap related reentry is a distinctive OAT, in which the ridge was used as the critical isthmus, whereas the previous ablated MI line is not part of the reentry. MI pseudo-block due to the ridge gap may lead to this type of recurrent tachycardia.