MSCT对房颤患者二尖瓣峡部形态的评价

Morphology of Mitral Isthmus:Evaluation by MSCT in Patients with Atrial Fibrillation

目的:探讨MSCT对房颤患者二尖瓣峡部(mitral isthmus,MI)解剖形态的评价的可行性。方法:收集拟行射频消融术的43例房颤患者的心脏MSCT图像,包括持续性房颤15例,阵发性房颤28例,观察MI形态,比较两组的差异。结果:MI形态分为平坦型和隆起型,持续性房颤组MI形态呈平坦型的概率较阵发性房颤组高,差异有统计学意义(P<0.05)。两组患者MI长度无统计学差异。持续性房颤组和阵发性房颤组在MI旁见左旋支的概率分别为87%和82%。房颤患者MI线与左旋支最短距离为0.58±0.25mm。结论:与阵发性房颤患者相比,持续性房颤患者MI长度无显著差异,但曲度减轻,趋于平坦。MI旁常有左旋支走形。MSCT可对房颤患者MI的形态进行精确评估,对射频消融治疗具有指导价值。

Objective To investigate the feasibility of MSCT in exploring the anatomical morphology of mitral isthmus(MI)in patients with atrial fibrillation(AF).Methods The CT findings of 43 patients with AF,Including 28 patients with paroxysmal AF and 15 patients with persistent AF,were analyzed retrospectively.MI morphology was observed and the differences between the two groups were compared.Results The MI form includes flat type and elevated type.The probability of the flat type was higher in the paroxysmal AF group than that in the paroxysmal AF group(P﹤0.05).The depth index of MI was smaller in persistent AF group than that in paroxysmal AF group,while the length index of MI had no statistical difference between the two groups.The probability of seeing the left circumflex coronary artery or its main branch beside the MI was 87%and 82%in the persistent and paroxysmal AF groups respectively.the length of MI had no statistical difference between the two groups.The probability of seeing the left circumflex coronary artery beside MI was 87%and 82%in the persistent and paroxysmal AF groups respectively.the shortest distance between MI line and left circumflex coronary artery was 0.58±0.25mm in patients with AF.Conclusions The length of MI had no statistical difference between the patients with paroxysmal AF and persistent AF.Compared with patients with paroxysmal AF,the curvature of MI was reduced and tended to be flat in patients with persistent AF.There's a higher probability of finding left circumflex coronary artery beside MI.MSCT can provide precise anatomic information about the morphology of MI in patients with AF,and has guiding value for radiofrequency ablation.