Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
J Cardiovasc Electrophysiol. 2020 May;31(5):1075-1082. doi: 10.1111/jce.14420. Epub 2020 Mar 9.
Atrial linear lesions are generally created with radiofrequency energy. We sought to evaluate the feasibility of cryothermal atrial linear ablation.
Twenty-one atrial fibrillation (AF) patients underwent linear ablation on the left atrial (LA) roof, mitral isthmus (MI), and cavotricuspid isthmus (CTI) with 8-mm-tip cryocatheters following pulmonary vein isolation. The data were compared with those of 31 patients undergoing linear ablation with irrigated-tip radiofrequency catheters. Conduction block was successfully created in 18 of 20 (90%), 9 of 21 (43%), and 20 of 20 (100%) on the LA roof, MI, and CTI by endocardial cryoablation alone with 19.0 (12.0-24.0), 30.0 (23.0-34.0), and 14.0 (14.0-16.0) minute cryo applications, respectively. The presence of either an interposed circumflex artery or pouch at the MI was significantly associated with failed MI block (P = .04). Conduction block was created in 25 of 31 (83.9%), 27 of 31 (87.1%), and 30 of 31 (96.8%) on the roof, MI, and CTI, respectively, by radiofrequency ablation. During the 17.5 (13.0-31.7) months of follow-up, freedom from AF/atrial tachycardia (AT) was significantly higher in the cryo group (P = .05); especially, recurrent AT was more frequent in the RF group (8/31 vs 1/21; P = .03). Conduction block across the roof, MI, and CTI was durable in 6 of 12 (50.0%), 4 of 12 (33.3%), and 9 of 12 (75.0%) patients during second procedures. All nine patients (except one) with recurrent ATs had at least one roof or MI conduction resumption.
Cryoablation is effective for creating a roof and CTI linear block, however, creating MI block by endocardial ablation alone was often challenging. Conduction resumption of LA linear block is common and recurrent arrhythmias, especially iatrogenic ATs, are more frequently observed after radiofrequency linear ablation.
线性消融通常采用射频能量。我们旨在评估冷冻消融在左心房（LA）房顶、二尖瓣峡部（MI）和三尖瓣峡部（CTI）线性消融中的可行性。
21 例房颤（AF）患者在肺静脉隔离后，使用 8 毫米冷冻消融导管进行 LA 房顶、MI 和 CTI 的线性消融。研究数据与 31 例行消融导管消融的患者进行比较。20 例患者（90%）LA 房顶、9 例患者（43%）MI 和 20 例患者（100%）CTI 仅通过心内膜冷冻消融即可成功建立传导阻滞，冷冻消融应用时间分别为 19.0（12.0-24.0）、30.0（23.0-34.0）和 14.0（14.0-16.0）分钟。MI 中存在回旋支动脉或隐窝与 MI 阻滞失败显著相关（P=0.04）。31 例患者中，25 例（83.9%）、27 例（87.1%）和 30 例（96.8%）的房顶、MI 和 CTI 分别通过射频消融建立了传导阻滞。在 17.5（13.0-31.7）个月的随访中，冷冻组的 AF/房性心动过速（AT）无复发率明显更高（P=0.05）；尤其是 RF 组复发 AT 更为频繁（8/31 比 1/21；P=0.03）。在第二次手术中，6 例（50.0%）、4 例（33.3%）和 9 例（75.0%）患者的房顶、MI 和 CTI 线性阻滞持续存在。9 例（除 1 例外）复发性 AT 患者至少有一处 LA 线性阻滞恢复。
冷冻消融可有效建立房顶和 CTI 线性阻滞，但单纯心内膜消融建立 MI 阻滞往往具有挑战性。LA 线性阻滞的传导恢复较为常见，射频线性消融后更常出现复发性心律失常，尤其是医源性 AT。
