Gunasekaran Suvai, Lee Daniel C, Knight Bradley P, Fan Lexiaozi, Collins Jeremy D, Chow Kelvin, Carr James C, Passman Rod, Kim Daniel
Department of Biomedical Engineering, Northwestern University, Evanston, Ill (S.G., L.F., D.K.); Department of Radiology (S.G., L.F., J.D.C., J.C.C., D.K.) and Division of Cardiology, Internal Medicine (D.C.L., B.P.K., R.P.), Northwestern University Feinberg School of Medicine, 737 N Michigan Ave, Suite 1600, Chicago, IL 60611; Department of Radiology, Mayo Clinic, Rochester, Minn (J.D.C.); and Cardiovascular MR R&D, Siemens Healthcare, Chicago, Ill (K.C.).
Radiol Cardiothorac Imaging. 2020 Apr 23;2(2):e190096. doi: 10.1148/ryct.2020190096.
To determine whether left ventricular (LV) extracellular volume (ECV) expansion is associated with atrial fibrillation (AF) or AF-mediated LV systolic dysfunction (LVSD) while minimizing the influence of biologic and imaging methodologic confounders.
This study examined the prevalence of LV ECV expansion in 137 patients with AF (mean age, 62 years ± 11 [standard deviation]; 92 male patients and 45 female patients; 83 paroxysmal and 54 persistent) who underwent preablation cardiovascular MRI. Biologic confounders were minimized by measuring the ECV fraction and excluding patients with severe LV hypertrophy, defined as wall thickness greater than 1.5 cm. Imaging confounders were minimized by using an arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping pulse sequence. Other cardiac functional parameters, including LV ejection fraction (LVEF) and left atrial end-diastolic volume indexed to body surface area, were assessed using cine cardiovascular MRI. A substudy was conducted in 32 patients with no AF (mean age, 54 years ± 16) in sinus rhythm to establish control values and convert these values between the AIR sequence and literature-based modified Look-Locker inversion recovery (MOLLI) values.
The mean ECV was not significantly different ( > .05) between patients with AF with a normal LVEF (24.5% ± 2.8; = 107), patients with AF with LVSD (24.5% ± 2.5; = 30), and patients with no AF (24.4% ± 3.8; = 32), but there was a significant interaction between ECV and CHADS-VASc score ( = .045). Compared with the literature data obtained from healthy control patients scanned using MOLLI, 99.3% of patients with AF had ECV below the fibrosis cutoff point (32.8% when converted from MOLLI T1 mapping to AIR T1 mapping), including a subset of patients with AF ( = 28) with low CHADS-VASc score (0/1 for men/women).
Study results suggest that an LV ECV expansion is not associated with AF or AF-mediated LVSD. . © RSNA, 2020See also the commentary by Stillman in this issue.
确定左心室（LV）细胞外容积（ECV）扩大是否与心房颤动（AF）或AF介导的左心室收缩功能障碍（LVSD）相关，同时尽量减少生物学和成像方法学混杂因素的影响。
本研究检查了137例接受消融术前心血管磁共振成像的AF患者（平均年龄62岁±11[标准差]；男性92例，女性45例；阵发性83例，持续性54例）中LV ECV扩大的患病率。通过测量ECV分数并排除严重左心室肥厚（定义为壁厚大于1.5 cm）的患者，将生物学混杂因素降至最低。通过使用心律失常不敏感快速（AIR）心脏T1映射脉冲序列，将成像混杂因素降至最低。使用电影心血管磁共振成像评估其他心脏功能参数，包括左心室射血分数（LVEF）和以体表面积为指数的左心房舒张末期容积。对32例窦性心律无AF的患者（平均年龄54岁±16）进行了一项子研究，以建立对照值并在AIR序列和基于文献的改良Look-Locker反转恢复（MOLLI）值之间转换这些值。
LVEF正常的AF患者（24.5%±2.8；n = 107）、LVSD的AF患者（24.5%±2.5；n = 30）和无AF的患者（24.4%±3.8；n = 32）之间的平均ECV无显著差异（P>0.05），但ECV与CHADS-VASc评分之间存在显著交互作用（P = 0.045）。与使用MOLLI扫描的健康对照患者获得的文献数据相比，99.3%的AF患者的ECV低于纤维化临界值（从MOLLI T1映射转换为AIR T1映射时为32.8%），包括一部分CHADS-VASc评分低的AF患者（n = 28）（男性/女性为0/1）。
研究结果表明，LV ECV扩大与AF或AF介导的LVSD无关。©RSNA，2020另见本期Stillman的评论。
