Novel "red‐bull sign" during cavotricuspid isthmus ablation: Indication of an ablation catheter stuck in the subeustachian pouch. Issue 6 (7th November 2022)

• Record Type: Journal Article
• Authors: Hirata, Moyuru; Nagashima, Koichi; Watanabe, Ryuta; Wakamatsu, Yuji; Otsuka, Naoto; Hayashida, Satoshi; Hirata, Shu; Sawada, Masanaru; Kurokawa, Sayaka; Okumura, Yasuo
• Is Part Of: Journal of arrhythmia. Volume 38:Issue 6(2022)
• Page Start: 1028
• Page End: 1034
• Publication Date: 2022-11-07
• Subjects: atrial flutter -- cavotricuspid isthmus -- second‐generation irrigated catheter -- subeustachian pouch -- temperature‐controlled ablation; Arrhythmia -- Periodicals; Cardiac pacing -- Periodicals; Arrhythmias, Cardiac; Arrhythmia; Cardiac pacing; Periodicals; Electronic journals; Periodicals; 616.128
• DOI: 10.1002/joa3.12793
• Languages: English
• ISSNs: 1880-4276

Abstract

Abstract: Background: A subeustachian pouch (SEP) often hinders the completion of a cavotricuspid isthmus (CTI) ablation of typical atrial flutter (AFL) and sometimes causes steam‐pops during a power‐controlled ablation. We hypothesized that real‐time bull's‐eye monitoring of the catheter surface temperature might be useful to locate the SEP where the temperature can rise rapidly, and a temperature‐controlled ablation might avoid steam pops. This study aimed to demonstrate this hypothesis. Methods: A temperature‐controlled CTI ablation with a QDOT MICRO™ catheter ( n = 10) and a conventional power‐controlled CTI ablation ( n = 10) were performed with an output power of 35 W. During the RF application, the bull's eye monitor for monitoring the catheter surface temperatures was assessed. A "red‐bull sign" was defined as an entire red‐colored bull's‐eye monitor, indicating that the catheter‐tip temperature of all 6 thermocouples rose rapidly over 47°C. Results: In a total of 115 lesions (12 ± 3 per patient), a "red‐bull sign" was observed in 39 (33.9%) lesions where the RF output was reduced to 26 ± 8 W. All 39 "red‐bull sign" lesions corresponded to the location of the SEP as delineated by ICE before the ablation. The red‐bull sign accurately indicated the presence of a SEP with a sensitivity of 84.7% and specificity of 100%. Bidirectional block of the CTI was completed in all patients in either catheter group without any steam‐pops. Conclusion: Real‐time surface temperature monitoring and a red‐bull sign might be useful to detect the SEP. A temperature‐controlled CTI ablation with the QDOT MICRO catheter might be safe for avoiding steam pops. Abstract : Real‐time catheter‐surface temperature monitoring with 6 thermocouples situated at the ablating electrode tip of the QDOT MICROTM catheter is useful for locating subeustachian pouches, which often hinder the completion of a cavotricuspid isthmus ablation of typical atrial flutter. A "red‐bull sign", defined as the bull's‐eye monitor colored entirely in red, indicating that the temperature on all 6 thermocouples rose rapidly over 47°C, accurately indicated the presence of a subeustachian pouch with a sensitivity of 84.7% and specificity of 100%.