One of the most helpful aspects of intracardiac echocardiography (ICE) implementation in electrophysiological studies (EPS) is the real-time visualisation of catheters and cardiac structures. In this prospective study, we investigated ICE-guided zero-fluoroscopy catheter navigation during radiofrequency (RF) ablation of the cavotricuspid isthmus (CTI) in patients with typical atrial flutter (AFL). Thirty consecutive patients (mean age 72.9 ± 11.4 years, 23 male) with ongoing (n = 23) or recent CTI-dependent AFL underwent an EPS, solely utilizing ICE for catheter navigation. Zero-fluoroscopy EPS could be successfully accomplished in all patients. Mean EPS duration was 41.4 ± 19.9 min, and mean ablation procedure duration was 20.8 ± 17.1 min. RF ablation was applied for 6.0 ± 3.1 min (50W, irrigated RF ablation). Echocardiographic parameters, such as CTI length, prominence of the Eustachian ridge (ER), and depth of the CTI pouch on the ablation plane, were assessed to analyse their correlation with EPS- or ablation procedure duration. The CTI pouch was shallower in patients with an ablation procedure duration above the median (4.8 ± 1.1 mm vs. 6.4 ± 0.9 mm, p = 0.04), suggesting a more lateral ablation plane in these patients, where the CTI musculature is stronger. CTI length or ER prominence above the respective median did not correlate with longer EPS duration. Zero-fluoroscopy CTI ablation guided solely by intracardiac echocardiography in patients with CTI-dependent AFL is feasible and safe. ICE visualisation may help to localise the optimal ablation plane, detect and correct poor tissue contact of the catheter tip, and recognise early potential complications during the ablation procedure.

中文翻译：

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通过心内超声心动图进行导管导航，可以在典型心房扑动患者中实现零透视线性病灶形成和双向腔三尖瓣峡部阻滞

在电生理学研究 (EPS) 中实施心内超声心动图 (ICE) 最有用的方面之一是导管和心脏结构的实时可视化。在这项前瞻性研究中，我们研究了典型心房扑动 (AFL) 患者三尖瓣峡部 (CTI) 射频 (RF) 消融过程中 ICE 引导的零透视导管导航。连续 30 名患有持续性 (n = 23) 或近期 CTI 依赖性 AFL 的患者（平均年龄 72.9 ± 11.4 岁，23 名男性）接受了 EPS，仅使用 ICE 进行导管导航。所有患者均可成功完成零透视 EPS。平均 EPS 持续时间为 41.4 ± 19.9 分钟，平均消融手术持续时间为 20.8 ± 17.1 分钟。射频消融持续 6.0 ± 3.1 分钟（50W，灌注射频消融）。评估超声心动图参数，例如 CTI 长度、咽鼓嵴 (ER) 突出度以及消融平面上 CTI 囊袋的深度，以分析它们与 EPS 或消融手术持续时间的相关性。消融手术持续时间高于中位数的患者的 CTI 储袋较浅（4.8 ± 1.1 mm 与 6.4 ± 0.9 mm，p = 0.04），表明这些患者的消融平面更横向，其中 CTI 肌肉组织更强。CTI 长度或 ER 突出程度高于各自的中位数与较长的 EPS 持续时间无关。对于 CTI 依赖性 AFL 患者，仅由心内超声心动图引导的零透视 CTI 消融是可行且安全的。ICE 可视化可能有助于定位最佳消融平面，检测和纠正导管尖端的不良组织接触，并识别消融过程中的早期潜在并发症。