Division of Cardiology, Fondazione Cardiocentro Ticino, Lugano, Switzerland.
JACC Cardiovasc Imaging. 2011 Jul;4(7):716-26. doi: 10.1016/j.jcmg.2011.03.018.
The aim of this study was to evaluate the feasibility and acute efficacy of real-time 3-dimensional transesophageal echocardiography (RT3DTEE)-guided ablation of the cavotricuspid isthmus (CVTI).
The use of RT3DTEE to guide a transcatheter radiofrequency ablation procedure has never been systematically investigated.
Seventy consecutive patients with CVTI-dependent atrial flutter underwent CVTI ablation. Procedural monitoring using RT3DTEE was assigned to patients who requested general anesthesia for the procedure (n = 21 [30%]). In the other 49 patients (the control group), the procedures were monitored using the standard fluoroscopic approach. Procedural time was considered as skin-to-skin electrophysiological procedure duration, not including anesthesia preparation; adequate radiofrequency ablation applications (with fixed temperature and power settings) were considered as lesions lasting ≥ 60 s.
RT3DTEE allowed visualization of the CVTI and identified related structures in most patients (20 of 21); anatomic features such as long CVTI (n = 11), prominent Eustachian ridge (n = 9), prominent Eustachian valve (n = 6), septal recess (n = 8), and pectinate muscles (n = 10) were frequent. Also, RT3DTEE allowed continuous visualization of ablation catheter movement and contact. Compared with the control group, RT3DTEE was equally effective in achieving CVTI bidirectional block (100% in both groups), and no complications occurred. RT3DTEE shortened procedural time (median 73.0 min, interquartile range [IQR] 60.0 to 90.0 min, vs. median 115.0 min, IQR 85.0 to 133.0 min, p < 0.001), reduced radiation exposure (median fluoroscopy time 4.2 min, IQR 3.1 to 8.4 min, vs. median 19.3 min, IQR 12.9 to 36.4 min, p < 0.001; median fluoroscopy dose 575.4 cGy · cm(2), IQR 428.5 to 1,299.4 cGy · cm(2), vs. median 3,520.7 cGy · cm(2), IQR 1,700.0 to 6,709.0 cGy · cm(2), p < 0.001), and reduced the number of radiofrequency applications to achieve bidirectional block (median 7, IQR 6 to 10, vs. median 12, IQR 10 to 22, p = 0.007). A strong learning curve was detected by comparing procedural data between the first and last patients treated using RT3DTEE.
RT3DTEE-guided ablation of CVTI was feasible, allowing real-time detailed morphological CVTI characterization as well as continuous visualization of the ablation catheter during radiofrequency ablation. This approach entailed marked reductions in procedural time, radiation exposure, and the number of radiofrequency applications.
本研究旨在评估实时三维经食管超声心动图（RT3DTEE）引导下消融三尖瓣峡部（CVTI）的可行性和即刻疗效。
使用 RT3DTEE 引导经导管射频消融术尚未得到系统研究。
70 例 CVTI 依赖性房扑患者接受 CVTI 消融术。21 例（30%）患者要求全身麻醉，对其进行 RT3DTEE 监测。其余 49 例患者（对照组）采用标准透视法进行监测。手术时间定义为皮肤到皮肤的电生理手术时间，不包括麻醉准备；消融导管的应用时间（固定温度和功率设置）≥60s 认为是有效的消融。
RT3DTEE 可在大多数患者（20/21）中显示 CVTI 并识别相关结构；解剖特征如 CVTI 较长（n=11）、Eustachian 嵴突出（n=9）、Eustachian 瓣突出（n=6）、间隔隐窝（n=8）和梳状肌（n=10）较常见。此外，RT3DTEE 还可以连续观察消融导管的移动和接触。与对照组相比，RT3DTEE 同样有效实现 CVTI 双向阻滞（两组均为 100%），且无并发症发生。RT3DTEE 缩短了手术时间（中位数 73.0 分钟，四分位距[IQR]60.0 至 90.0 分钟，vs. 中位数 115.0 分钟，IQR 85.0 至 133.0 分钟，p<0.001），减少了辐射暴露（中位数透视时间 4.2 分钟，IQR 3.1 至 8.4 分钟，vs. 中位数 19.3 分钟，IQR 12.9 至 36.4 分钟，p<0.001；中位数透视剂量 575.4 cGy·cm2，IQR 428.5 至 1,299.4 cGy·cm2，vs. 中位数 3,520.7 cGy·cm2，IQR 1,700.0 至 6,709.0 cGy·cm2，p<0.001），并减少了实现双向阻滞所需的射频消融次数（中位数 7，IQR 6 至 10，vs. 中位数 12，IQR 10 至 22，p=0.007）。通过比较使用 RT3DTEE 治疗的前 10 例和最后 10 例患者的手术数据，发现存在明显的学习曲线。
RT3DTEE 引导的 CVTI 消融术是可行的，可实时进行详细的 CVTI 形态学特征描述，并在射频消融过程中连续观察消融导管。这种方法显著减少了手术时间、辐射暴露和射频消融次数。
