From the Department of Cardiology (M.H., J.A.C.L., I.M.K., K.F., D.S., H.A., J.R., J.E.M., H.C., S.N.), Department of Radiology (S.L.Z.), The Johns Hopkins University School of Medicine, Baltimore, MD; and Department of Biostatistics (V.Z.), Department of Epidemiology (S.N.), The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
Circ Cardiovasc Imaging. 2015 Feb;8(2):e002769. doi: 10.1161/CIRCIMAGING.114.002769.
Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF.
LA structure and function was measured in 90 patients with AF (age 61±10 years; 76% men) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain, LA systolic strain rate, and early and late diastolic strain rates were measured using cine-cardiac magnetic resonance images acquired during sinus rhythm. The degree of LGE was quantified. Compared with patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (56±17 versus 49±13 mL/m(2); P=0.036), and increased LGE (27.1±11.7% versus 36.8±14.8%; P<0.001). Aside from LA active emptying fraction, all LA parameters (passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate) were lower in patients with persistent AF (P<0.05 for all). Healthy volunteers had less LGE and higher LA functional parameters compared with patients with AF (P<0.05 for all). In multivariable analysis, increased LGE was associated with lower LA passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate (P<0.05 for all).
Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking cardiac magnetic resonance may add important information about the physiological importance of LA fibrosis.
心房颤动（AF）与左心房（LA）结构和功能变化有关。心脏磁共振延迟钆增强（LGE）和特征追踪分别能够无创定量测量 LA 纤维化和心肌运动。我们旨在研究 AF 患者左心房功能与 LA 增强之间的关系。
对 90 例因消融而就诊的 AF 患者（年龄 61±10 岁；76%为男性）和 14 例健康志愿者进行了 LA 结构和功能的测量。在窦性心律下采集电影心脏磁共振图像，测量峰值全局纵向 LA 应变、LA 收缩期应变率以及早期和晚期舒张期应变率。量化 LGE 程度。与阵发性 AF 患者（队列的 60%）相比，持续性 AF 患者的最大 LA 容积指数更大（56±17 与 49±13 mL/m²；P=0.036），LGE 也更高（27.1±11.7%与 36.8±14.8%；P<0.001）。除 LA 主动排空分数外，所有 LA 参数（被动排空分数、峰值全局纵向 LA 应变、收缩期应变率、早期舒张期应变率和晚期舒张期应变率）在持续性 AF 患者中均较低（所有 P<0.05）。与 AF 患者相比，健康志愿者的 LGE 较少，LA 功能参数较高（所有 P<0.05）。多变量分析显示，增加的 LGE 与较低的 LA 被动排空分数、峰值全局纵向 LA 应变、收缩期应变率、早期舒张期应变率和晚期舒张期应变率相关（所有 P<0.05）。
LA 增强与 LA 储备、输送和助推泵功能降低有关。使用特征追踪心脏磁共振对 LA 功能进行时相测量可能会提供有关 LA 纤维化生理重要性的重要信息。
