Candeias Rui, Adragcão Pedro, Cavaco Diogo, Reis-Santos Katya, Vieira Pinheiro, Morgado Francisco, Bonhorst Daniel, Silva Aniceto
Serviço de Cardiologia, Hospital Santa Cruz, Carnaxide, Portugal.
Rev Port Cardiol. 2009 Oct;28(10):1031-40.
Maintenance of atrial fibrillation (AF) depends on the presence of multiple reentrant circuits in the atria. In AF ablation, after pulmonary vein (PV) isolation, substrate modification can be increased by performing linear lesions in the left atrium that reduce the fibrillatory surface. A cavotricuspid isthmus (CTI) block may be an easier and safer alternative to left atrial lines for this purpose. Non-inducibility after AF ablation is associated with a higher success rate. The aim of this study is to assess whether CTI ablation after PV isolation reduces inducibility of atrial arrhythmias, particularly AF.
In 29 consecutive patients (23 male, mean age 54.6+/-11.4 years, 11 (38%) with hypertension and four (14%) with structural heart disease, mean left atrial dimension 43+/-6 mm) undergoing PV isolation for paroxysmal or persistent AF, atrial arrhythmia inducibility was tested before and after CTI ablation. The procedure was performed using a CARTO-Merge mapping system, one or two Lasso catheters, an irrigated ablation catheter and radiofrequency energy. Atrial arrhythmia inducibility was tested with burst pacing down to 150 ms or atrial refractoriness from the proximal coronary sinus. Atrial arrhythmias were considered inducible if they persisted for more than 60 seconds. Of the 29 patients, 26 (90%) had an inducible arrhythmia before CTI ablation--AF in 16, typical atrial flutter (AFL) in seven and atypical AFL in three. Three (10%) were non-inducible. After CTI ablation, only 11 patients (38%) maintained arrhythmia inducibility (p<0.001)--AF in nine and atypical AFL in two. There was a significant reduction of AF inducibility (16 vs. 9/29, p=0.016) and of combined AF and atypical AFL inducibility (19 vs. 11/29, p=0.021). After one year of follow-up, 23 patients (79%) had no recurrence of arrhythmia. Success rates were 83% in patients without and 73% in patients with inducible arrhythmias at the end of the procedure (p=NS).
CTI ablation, in addition to PV isolation, significantly reduced the number of patients with inducible atrial arrhythmias and inducible AF.
房颤（AF）的维持取决于心房内多个折返环的存在。在房颤消融中，肺静脉（PV）隔离后，可通过在左心房进行线性消融以减少颤动面积来增强基质改良。为此，三尖瓣峡部（CTI）阻滞可能是一种比左心房线性消融更简便、更安全的替代方法。房颤消融后不能诱发心律失常与更高的成功率相关。本研究旨在评估PV隔离后CTI消融是否能降低房性心律失常尤其是房颤的诱发率。
连续纳入29例因阵发性或持续性房颤接受PV隔离的患者（男性23例，平均年龄54.6±11.4岁，11例（38%）有高血压，4例（14%）有结构性心脏病，平均左心房内径43±6mm），在CTI消融前后测试房性心律失常的诱发情况。使用CARTO-Merge标测系统、一或两根Lasso导管、一根灌注消融导管及射频能量进行该操作。通过将起搏周长降至150ms或从冠状窦近端测量心房不应期来测试房性心律失常的诱发情况。若心律失常持续超过60秒，则认为可诱发。29例患者中，26例（90%）在CTI消融前可诱发心律失常——16例为房颤，7例为典型房扑（AFL），3例为非典型AFL。3例（10%）不可诱发。CTI消融后，仅11例患者（38%）仍可诱发心律失常（p<0.001）——9例为房颤，2例为非典型AFL。房颤诱发率（16例vs.9/29例，p=0.016）以及房颤与非典型AFL联合诱发率（19例vs.11/29例，p=0.021）均显著降低。随访一年后，23例患者（79%）无心律失常复发。操作结束时，无诱发心律失常的患者成功率为83%，有诱发心律失常的患者成功率为73%（p=无显著差异）。
除PV隔离外，CTI消融显著减少了可诱发房性心律失常及可诱发房颤的患者数量。
