Takahashi Masao, Kujiraoka Hirofumi, Arai Tomoyuki, Hojo Rintaro, Fukamizu Seiji
Department of Cardiology, Tokyo Metropolitan Hiroo Hospital, 2-34-10 Ebisu Shibuya-ku, Tokyo 150-0013, Japan.
Eur Heart J Case Rep. 2023 Dec 18;8(1):ytad598. doi: 10.1093/ehjcr/ytad598. eCollection 2024 Jan.
The radiofrequency catheter ablation of peri-mitral atrial flutter is occasionally difficult, mostly due to epicardial or intramural conduction on the mitral isthmus (MI). However, cryoballoon ablation (CBA) of peri-mitral atrial flutter refractory to radiofrequency ablation has not been reported.
We report a case of a 66-year-old male patient who experienced a recurrence of atypical atrial flutter and underwent the sixth catheter ablation. The activation and entrainment maps showed that this atypical atrial flutter (AFL) was peri-mitral AFL via pathways other than endocardial conduction in the MI. Previous radiofrequency catheter ablation attempts on the MI line, including endocardial, coronary sinus, and epicardial ablations, failed to achieve a bidirectional block of the MI. In this case, we selected CBA for the MI area and successfully achieved a bidirectional block of the MI.
Although using CBA in the MI is off-label, it could be safely implemented using CARTOUNIVU™. We attributed the success of the bidirectional block of the MI in this case to the crimping of the northern hemisphere of the CBA to the mitral isthmus area, which resulted in the formation of a broad, uniform, and deep ablation lesion site.
二尖瓣周围房扑的射频导管消融术有时较为困难，主要原因是二尖瓣峡部（MI）存在心外膜或壁内传导。然而，对于射频消融难治的二尖瓣周围房扑的冷冻球囊消融（CBA）尚未见报道。
我们报告一例66岁男性患者，其非典型房扑复发并接受了第六次导管消融术。激动标测和拖带标测显示，这种非典型房扑（AFL）是通过二尖瓣峡部心内膜传导以外的途径形成的二尖瓣周围AFL。先前在二尖瓣峡部线进行的射频导管消融尝试，包括心内膜、冠状窦和心外膜消融，均未能实现二尖瓣峡部的双向阻滞。在本病例中，我们选择对二尖瓣峡部区域进行CBA，并成功实现了二尖瓣峡部的双向阻滞。
尽管在二尖瓣峡部使用CBA属于超适应证应用，但使用CARTOUNIVU™可安全实施。我们将本病例中二尖瓣峡部双向阻滞的成功归因于CBA北半球对二尖瓣峡部区域的压接，这导致形成了一个广泛、均匀且深的消融病变部位。
