心房颤动患者左心室心肌纤维化的MR定量分析研究

摘要

目的 采用MR纵向弛豫时间(T1 mapping)定量评估心房颤动(房颤)患者左心室心肌纤维化情况.方法 连续入组60例房颤患者(持续性房颤30例、阵发性房颤30例)和59名正常对照,均接受心脏MR检查,分别行心脏电影成像和延迟增强成像,并采用运动自动矫正反转恢复真实稳态自由进动序列进行T1 mapping成像.测量左心室心肌增强前T1值并计算细胞外容积(ECV),并与正常对照比较.结果 所有患者均完成心脏MR检查,未见心肌延迟强化.正常对照左心室增强前心肌T1值小于阵发性房颤患者及持续性房颤患者,且持续性房颤患者左心室增强前心肌T1值高于阵发性房颤患者(P均＜0.05).正常对照左心室心肌ECV与阵发性房颤患者差异无统计学意义(P＞0.05),而小于持续性房颤患者(P＜0.05),持续性房颤患者左心室心肌ECV大于阵发性房颤患者(P＜0.05).房颤患者心功能各项指标与左心室增强前心肌T1值、ECV均呈正相关(P均＜0.05).结论 房颤患者存在左心室心肌纤维化,且持续性房颤患者较阵发性房颤患者更严重.%Objective To evaluate the diffuse myocardial fibrosis of the left ventricle (LV) in patients with atrial fibrillation (AF) by cardiac MR (CMR) T1 mapping methods.Methods Totally 60 subjects (30 paroxysmal AF patients and 30 persistent AF patients) and 59 normal control underwent MR cardiac cine,late gadolinium enhancement,and LV T1 mapping.For T1 mapping,modified Look-Locker inversion recovery sequence was used.Compared with control,pre-contrast ventricular T1 times were quantified and extracellular volume (ECV) was calculated.Results All subjects completed the CMR exam,no myocardial delay enhanced lesion was found.Pre-contrast ventricular T1 time in healthy controls was lower than that in patients with persistent and paroxysmal AF,and the pre-comrast ventricular T1 time in persistent AF patients was higher than that of paroxysmal AF patients (all P＜0.05).The mean LV myocardial ECV had no statistical difference between healthy controls and paroxysmal AF patients (P＞ 0.05),while lower than persistent AF patients (P ＜ 0.05).The mean LV myocardial ECV in patients with persistent AF was larger than that in patients with paroxysmal AF (P＜0.05).LV functional indexes were positive correlated with pre-contrast ventricular T1 time and ECV in patients with AF (all P＜0.05).Conclusion There is LV myocardial fibrosis in patients with AF,and the degree in patients with persistent AF is more severe than that in patients with paroxysmal AF.