Garcia Julio, Sheitt Hana, Bristow Michael S, Lydell Carmen, Howarth Andrew G, Heydari Bobak, Prato Frank S, Drangova Maria, Thornhill Rebecca E, Nery Pablo, Wilton Stephen B, Skanes Allan, White James A
Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada.
Department of Radiology, University of Calgary, Calgary, AB, Canada.
J Magn Reson Imaging. 2020 Mar;51(3):871-884. doi: 10.1002/jmri.26876. Epub 2019 Jul 23.
Characterization of left atrial (LA) hemodynamics in paroxysmal atrial fibrillation (PAF) may provide valuable insights for thromboembolic risk.
To evaluate LA vortex formation and velocity distributions by 4D flow MRI and identify associations with age, LA/LV (left ventricle) function, and established risk scores.
Prospective clinical.
Patients with PAF (n = 45, 46 ± 14 years) and healthy controls (n = 15, 54 ± 9 years) were enrolled.
3T standardized cardiac MRI protocol inclusive of 4D flow MRI.
Flow analysis planes were prescribed at each pulmonary vein. Velocity distribution analysis and vortex size quantification by the Lambda2 (λ ) method were performed in the LA.
Pearson or Spearman's correlation coefficients, r, were calculated to identify relationships between 4D flow-derived LA parameters and age, LA/LV function, and CHA DS -VASc stroke risk score. Univariate and multivariate determinants of stroke risk were assessed using linear regressions. To compare parameters within multiple groups, one-way analysis of variance or Kruskal-Wallis was used.
LA vortice sizes were observed in all subjects using λ showing inverse correlations with peak pulmonary vein inflow velocities (P < 0.05), and positive correlations with LA volume (P < 0.05). Vortex size was elevated in PAF at all phases of the cardiac cycle, being most prominent at end early diastole (3.98 ± 1.84 cm vs. 6.93 ± 3.11 cm , P = 0.001). Velocity distribution analysis showed a greater incidence of flow stasis among patients with PAF (P < 0.05). In univariate regression, vortex size was associated with the CHA DS -VASc risk score at peak systole (0.457 ± 0.038, P ≤ 0.001). However, in multivariate regression age was the dominant determinant of stroke risk (0.348 ± 0.012, P = 0.006).
This study demonstrated that LA vortex size is increased among low-risk patients with PAF and is associated with the CHA DS -VASc risk score. Age remained the dominant determinant of stroke risk.
2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:871-884.
阵发性心房颤动（PAF）患者左心房（LA）血流动力学特征可为血栓栓塞风险提供有价值的见解。
通过四维血流磁共振成像（4D流MRI）评估左心房涡流形成和速度分布，并确定其与年龄、左心房/左心室（LV）功能及既定风险评分的相关性。
前瞻性临床研究。
纳入PAF患者（n = 45，46±14岁）和健康对照者（n = 15，54±9岁）。
MRI序列：3T标准化心脏MRI方案，包括4D流MRI。
在每条肺静脉处设定血流分析平面。采用Lambda2（λ）方法对左心房进行速度分布分析和涡流大小量化。
计算Pearson或Spearman相关系数r，以确定4D流衍生的左心房参数与年龄、左心房/左心室功能及CHA₂DS₂-VASc卒中风险评分之间的关系。采用线性回归评估卒中风险的单因素和多因素决定因素。为比较多组内的参数，采用单因素方差分析或Kruskal-Wallis检验。
使用λ方法在所有受试者中均观察到左心房涡流大小，其与肺静脉峰值流入速度呈负相关（P < 0.05），与左心房容积呈正相关（P < 0.05）。在心动周期的各个阶段，PAF患者的涡流大小均升高，在舒张早期末最为显著（3.98±1.84 cm对6.93±3.11 cm，P = 0.001）。速度分布分析显示，PAF患者血流淤滞的发生率更高（P < 0.05）。在单因素回归中，涡流大小与收缩期峰值时的CHA₂DS₂-VASc风险评分相关（0.457±0.038，P≤0.001）。然而，在多因素回归中，年龄是卒中风险的主要决定因素（0.348±0.012，P = 0.006）。
本研究表明，低风险PAF患者的左心房涡流大小增加，且与CHA₂DS₂-VASc风险评分相关。年龄仍然是卒中风险的主要决定因素。
2级 技术效能：3级 《磁共振成像杂志》2020年；51:871-884。
