Atrial flutter (AFL) represents a prevalent variant of supraventricular tachycardia, distinguished by a macro-reentrant pathway encompassing the cavotricuspid isthmus (CTI). Radiofrequency (RF) catheter ablation stands as the favored therapeutic modality for managing recurring CTI-dependent AFL. Intracardiac echocardiography (ICE) has been proposed as a method to reduce radiation exposure during CTI ablation. This study aims to comprehensively compare procedural parameters between ICE-guided CTI ablation and fluoroscopy-only procedures. A total of 370 consecutive patients were enrolled in our single-center retrospective study. In 151 patients, procedures were performed using fluoroscopy guidance only, while 219 patients underwent ICE-guided CTI ablation. ICE guidance significantly reduced fluoroscopy time (73 (36; 175) s vs. 900 (566; 1179) s; p < 0.001), fluoroscopy dose (2.45 (0.6; 5.1) mGy vs. 40.5 (25.7; 62.9) mGy; p < 0.001), and total procedure time (70 (52; 90) min vs. 87.5 (60; 102.5) min; p < 0.001). Total ablation time (657 (412; 981) s vs. 910 (616; 1367) s; p < 0.001) and the time from the first to last ablation (20 (11; 36) min vs. 40 (25; 55) min; p < 0.01) were also significantly shorter in the ICE-guided group. Acute success rate was 100% in both groups, and no major complications occurred in either group. ICE-guided CTI ablation in patients with AFL resulted in shorter procedure times, reduced fluoroscopy exposure, and decreased ablation times, compared to the standard fluoroscopy-only approach.

Radiofrequency (RF) catheter ablation is an effective treatment option for targeting the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT). Previous data suggested that using intracardiac echocardiography (ICE) guidance could improve procedural outcomes when compared to using fluoroscopy alone. In this prospective study, we aimed to compare the effectiveness of an electroanatomical mapping system (EAMS)-guided approach with an ICE-guided approach for SP ablation. Eighty patients undergoing SP ablation for AVNRT were randomly assigned to either the ICE-guided or EAMS-guided group. If the procedural endpoint was not achieved after 8 RF applications; patients were allowed to crossover to the ICE-guided group. The ICE-guided approach reduced the total procedure time (61.0 (56.0; 66.8) min vs. 71.5 (61.0; 80.8) min, p < 0.01). However, the total fluoroscopy time was shorter (0 (0–0) s vs. 83.5 (58.5–133.25) s, p < 0.001) and the radiation dose was lower (0 (0–0) mGy vs. 3.3 (2.0–4.7) mGy, p < 0.001) with EAMS-guidance. The ICE-guided group had a lower number of RF applications (4 (3–5) vs. 5 (3.0–7.8), p = 0.03) and total ablation time (98.5 (66.8–186) s vs. 136.5 (100.5–215.8) s, p = 0.02). Nine out of 40 patients (22.5%) in the EAMS-guided group crossed over to the ICE-guided group, and they were successfully treated with similar RF applications in terms of number, time, and energy compared to the ICE-guided group. There were no recurrences during the follow-up period. In conclusion, the utilization of ICE guidance during SP ablation has demonstrated notable reductions in procedural time and RF delivery when compared to procedures guided by EAMS. In challenging cases, an early switch to ICE-guided ablation may be the optimal choice for achieving successful treatment.

Background: Catheter ablation is a standard intervention for typical atrial flutters, specifically targeting the cavotricuspidal isthmus (CTI). Intracardiac echocardiography (ICE) plays a pivotal role in providing real-time visualization of anatomical structures during the electrophysiology procedure, thereby enhancing safety and potentially reducing reliance on fluoroscopy, leading to improved procedural outcomes. We aimed to conduct a comparative analysis of procedural and follow-up outcomes between ICE-guided and fluoroscopy-only guided catheter ablations for CTI in patients undergoing treatment for typical atrial flutter. Methods: A retrospective analysis was conducted at our university center, encompassing 376 consecutive patients in a single-center study. Of these, 158 underwent procedures guided solely by fluoroscopy, while 218 received ICE-guided CTI ablation. Results: ICE-guidance demonstrated a statistically significant reduction in fluoroscopy time (72 [36; 170] s vs. 888 [578; 1184] s; p<0.01), total procedure time (70 [52; 90] min vs. 90 [60; 105] min; p<0.01), total ablation time (692 [435; 998] s vs. 920 [629; 1373] s; p<0.01), and the duration from the first to last ablation (20.5 [12; 37] min vs. 41.0 [26.8; 59.3] min; p<0.01). Both groups achieved a 100% acute success rate without major complications. The ICE-guided group exhibited a significantly superior long-term success rate (ICE-guided group: 95.74%, fluoroscopy-only group: 89.26%; p=0.048) compared to the fluoroscopy-only group at an average follow-up length of 34 months. Conclusion: The utilization of ICE-guidance for CTI ablation significantly reduces fluoroscopy exposure, procedure time, and ablation time, ultimately contributing to enhanced long-term success rates when compared to the conventional fluoroscopy-only approach.