P420Improved real time recordings using the third generation cryoballoon technology - detection of dual fascicle electrograms. (18th June 2020) - Velagic, V
Abstract: Introduction: The third-generation cryoballoon has been designed with a 40% shortened tip length compared with the former second-generation CB device. Ideally, a shorter tip could result with an improved visualization of real-time (RT) recordings in the pulmonary vein (PV) due to a more proximal positioning of the inner lumen mapping catheter. Beside the high incidence of RT recordings, for the first time, we observed dual fascicle electrograms with different isolation time for each fascicle, when using the new device. Purpose: We sought to analyze the rate of visualization of RT recordings and dual fascicle electrograms in our first series of patients with the third generation cryoballoon device. Methods: All consecutive patients having undergone CB ablation using the third generation technology were analyzed. Procedures were performed under conscious sedation. A single transeptal puncture was preformed guided by intracardial ultrasound and a 28 mm cryoballoon was used. A single 180 seconds freeze strategy was employed. Results: A total of 80 consecutive patients (77.5% male, 60.3 ± 10.8 years) were evaluated. Real-time recordings were detected in 275 of 320 PVs (85.9%). Specifically, RT recordings could be visualized in 68 left superior PVs (85%), 69 left inferior PVs (86.2%), 73 right superior PVs (91.2%), and 65 right inferior PVs (81.2%). Furthermore, in 14 of 320 PVs (4.3%) two different fascicles electrograms were detected. A distinctive isolation time for each fascicle could be observed both in sinus rhythm and in atrial fibrillation (Picture). Most commonly, dual fascicles were observed in left superior PV (7.5%) and right inferior PV (6.3%). In the rest of the veins this phenomenon was not so frequent. In 2.5% of right superior PV and in only 1.2% of left inferior PV dual fascicles could be observed. Conclusion: The rate of visualization of RT recordings is significantly high during third generation CB ablation. Real-time recordings can be visualized in 85.9% of veins with this novel cryoballoon. Furthermore, for the first time, isolation of two different fascicles during a single cryoballoon lesion could be observed. Other that more proximal mapping catheter position, there is second possible explanation for the visualization of dual fascicles with this novel balloon. Shorter tip could result with poorer cryoballoon stability and weaker contact with the atrium wall, hence non-uniform freezing and isolation of different fascicles in different times.