Abstract：
BACKGROUND: Although radiofrequency ablation of the cavotricuspid isthmus (CTI), responsible for sustaining atrial flutter, is a highly effective procedure, in extended patients\' observations following this procedure, more than every tenth becomes unsuccessful. Therefore, this study aimed to provide helpful information about the anatomy of the CTI in transthoracic echocardiography, which can aid in better planning of the CTI radiofrequency ablation in patients with typical atrial flutter.
METHODS: 56 patients with typical atrial flutter after radiofrequency ablation were evaluated at the end of the 24-month observation period. With substernal modified transthoracic echocardiographic (mTTE) evaluation, we identified four main anatomical obstacles impeding radiofrequency ablation. These obstacles were tricuspid annular plane systolic excursion, cavotricuspid isthmus length, cavotricuspid isthmus morphology, and the presence of a prominent Eustachian ridge/Eustachian valve. All intraprocedural radiofrequency ablation data were collected for analysis and correlated with anatomical data.
RESULTS: In the 24-month observation period, freedom from atrial flutter was 67.86%. The mean length of the isthmus was 30.34 ± 6.67 mm. The isthmus morphology in 56 patients was categorized as flat (n = 27; 48.2%), concave (n = 10; 17.85%), and pouch (n = 19, 33.9%). A prominent Eustachian ridge was observed in 23 patients (41.1%). Lack of anatomical obstacles in mTTE evaluation resulted in 100% efficacy, while the presence of at least two obstacles significantly increased the risk of unsuccessful ablation with more than two (OR 12.31 p = 0.01). Generally, 8 mm electrodes were the most effective for non-difficult CTI, while 3.5 mm electrodes used with a 3D system had highest performance for complex CTI. Notably, aging was the only factor that worsened the long-term outcome (OR 1.07 p = 0.044).
CONCLUSIONS: Preoperative usage of mTTE evaluation helps predict difficulty in cavotricuspid isthmus radiofrequency ablation, thus allowing better planning of the radiofrequency ablation strategy using the most accurate radiofrequency ablation electrode.
METHODS: 56 patients with typical atrial flutter after radiofrequency ablation were evaluated at the end of the 24-month observation period. With substernal modified transthoracic echocardiographic (mTTE) evaluation, we identified four main anatomical obstacles impeding radiofrequency ablation. These obstacles were tricuspid annular plane systolic excursion, cavotricuspid isthmus length, cavotricuspid isthmus morphology, and the presence of a prominent Eustachian ridge/Eustachian valve. All intraprocedural radiofrequency ablation data were collected for analysis and correlated with anatomical data.
RESULTS: In the 24-month observation period, freedom from atrial flutter was 67.86%. The mean length of the isthmus was 30.34 ± 6.67 mm. The isthmus morphology in 56 patients was categorized as flat (n = 27; 48.2%), concave (n = 10; 17.85%), and pouch (n = 19, 33.9%). A prominent Eustachian ridge was observed in 23 patients (41.1%). Lack of anatomical obstacles in mTTE evaluation resulted in 100% efficacy, while the presence of at least two obstacles significantly increased the risk of unsuccessful ablation with more than two (OR 12.31 p = 0.01). Generally, 8 mm electrodes were the most effective for non-difficult CTI, while 3.5 mm electrodes used with a 3D system had highest performance for complex CTI. Notably, aging was the only factor that worsened the long-term outcome (OR 1.07 p = 0.044).
CONCLUSIONS: Preoperative usage of mTTE evaluation helps predict difficulty in cavotricuspid isthmus radiofrequency ablation, thus allowing better planning of the radiofrequency ablation strategy using the most accurate radiofrequency ablation electrode.
摘要：
背景：尽管三尖瓣环峡部（CTI）的射频消融，负责维持房扑,是一个非常有效的程序，在此程序之后的扩展患者观察中，超过十分之一变得不成功。因此,这项研究旨在提供有关经胸超声心动图中CTI解剖的有用信息，这可以帮助更好地规划典型房扑患者的CTI射频消融。
方法：在24个月的观察期结束时，对56例射频消融术后出现典型扑动的患者进行评估。胸骨后改良经胸超声心动图（mTTE）评估，我们确定了4个阻碍射频消融的主要解剖学障碍.这些障碍是三尖瓣环平面收缩期偏移，三尖瓣峡部长度，三尖瓣峡部形态，和突出的咽鼓管脊/咽鼓管瓣膜的存在。收集所有术中射频消融数据进行分析，并与解剖数据相关。
结果：在24个月的观察期内，无房扑发生率为67.86%。峡部的平均长度为30.34±6.67mm。56例患者的峡部形态被归类为扁平（n=27；48.2％），凹（n=10；17.85%），和邮袋（n=19，33.9%）。在23例患者中观察到明显的咽鼓岭（41.1％）。mTTE评估中缺乏解剖学障碍导致100％疗效，而至少两个障碍物的存在显着增加了两个以上的消融失败的风险（OR12.31p=0.01）。一般来说,8毫米电极是最有效的非困难的CTI，而与3D系统一起使用的3.5mm电极对于复杂的CTI具有最高的性能。值得注意的是,衰老是导致长期结局恶化的唯一因素(OR1.07p=0.044).
结论：术前使用mTTE评估有助于预测三尖瓣峡部射频消融的难度，从而允许使用最精确的射频消融电极更好地规划射频消融策略。
方法：在24个月的观察期结束时，对56例射频消融术后出现典型扑动的患者进行评估。胸骨后改良经胸超声心动图（mTTE）评估，我们确定了4个阻碍射频消融的主要解剖学障碍.这些障碍是三尖瓣环平面收缩期偏移，三尖瓣峡部长度，三尖瓣峡部形态，和突出的咽鼓管脊/咽鼓管瓣膜的存在。收集所有术中射频消融数据进行分析，并与解剖数据相关。
结果：在24个月的观察期内，无房扑发生率为67.86%。峡部的平均长度为30.34±6.67mm。56例患者的峡部形态被归类为扁平（n=27；48.2％），凹（n=10；17.85%），和邮袋（n=19，33.9%）。在23例患者中观察到明显的咽鼓岭（41.1％）。mTTE评估中缺乏解剖学障碍导致100％疗效，而至少两个障碍物的存在显着增加了两个以上的消融失败的风险（OR12.31p=0.01）。一般来说,8毫米电极是最有效的非困难的CTI，而与3D系统一起使用的3.5mm电极对于复杂的CTI具有最高的性能。值得注意的是,衰老是导致长期结局恶化的唯一因素(OR1.07p=0.044).
结论：术前使用mTTE评估有助于预测三尖瓣峡部射频消融的难度，从而允许使用最精确的射频消融电极更好地规划射频消融策略。
