Extracellular volume fraction is more closely associated with altered regional left ventricular velocities than left ventricular ejection fraction in nonischemic cardiomyopathy.
Extracellular volume fraction is more closely associated with altered regional left ventricular velocities than left ventricular ejection fraction in nonischemic cardiomyopathy.
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DOI：
10.1161/circimaging.114.001998
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发表时间：
2015-01
期刊：
影响因子：
--
通讯作者：
Markl M
中科院分区：
文献类型：
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作者：
Collins J;Sommerville C;Magrath P;Spottiswoode B;Freed BH;Benzuly KH;Gordon R;Vidula H;Lee DC;Yancy C;Carr J;Markl M
非缺血性心肌病（NICM）是左心室功能障碍和心肌纤维化的常见原因。本研究的目的是无创评估NICM患者节段性左室细胞外体积分数（ECV）、左室速度、心肌疤痕和壁运动的变化。对31例NICM患者（50±18岁）进行心脏MRI，包括造影前和造影后心肌t1制图和左室（基底、中室、尖短轴）速度定量（组织相制图，TPM）。采用16节段AHA模型分析ECV的节段分布、心肌收缩和舒张峰值速度、晚期钆增强（LGE）判断的瘢痕、壁运动异常。伴有瘢痕或壁运动受损的左室段与ECV升高（r=0.26, p<0.001）和收缩径向速度峰值降低（r= - 0.43, p<0.001）显著相关。左室射血分数降低（n=12， ECV=0.28±0.06）和左室射血分数保持（n=19， ECV=0.30±0.09）的患者局部心肌速度和ECV相似。保留LVEF的患者在增加ECV与降低收缩期（r= - 0.19, r= - 0.30）和舒张期（r=0.34, r=0.26）径向和长轴峰值速度之间存在显著关系（p<0.001）。即使在排除LGE的心肌节段后，ECV与节段左室速度之间仍保持着显著的关系，这表明ECV升高有可能识别LGE不可见的区域性弥漫性纤维化，这与区域性左室功能受损有关。局部ECV升高与心肌速度降低的关联与LVEF无关，表明NICM中ECV改变与节段性心肌功能之间存在结构-功能关系。
Non-ischemic cardiomyopathy (NICM) is a common cause of left ventricular (LV) dysfunction and myocardial fibrosis. The purpose of this study was to non-invasively evaluate changes in segmental LV extracellular volume fraction (ECV), LV velocities, myocardial scar, and wall motion in NICM patients. Cardiac MRI including pre- and post-contrast myocardial T1-mapping and velocity quantification (tissue phase mapping, TPM) of the LV (basal, mid-ventricular, apical short axis) was applied in 31 patients with NICM (50±18years). Analysis based on the 16-segment AHA model was employed to evaluate the segmental distribution of ECV, peak systolic and diastolic myocardial velocities, scar determined by late gadolinium enhancement (LGE), and wall motion abnormalities. LV segments with scar or impaired wall motion were significantly associated with elevated ECV (r=0.26, p<0.001) and reduced peak systolic radial velocities (r=−0.43, p<0.001). Regional myocardial velocities and ECV were similar for patients with reduced (n=12, ECV=0.28±0.06) and preserved LV ejection fraction (LVEF) (n=19, ECV=0.30±0.09). Patients with preserved LVEF showed significant relationships between increasing ECV and reduced systolic (r=−0.19, r=−0.30) and diastolic (r=0.34, r=0.26) radial and long-axis peak velocities (p<0.001). Even after excluding myocardial segments with LGE, significant relationships between ECV and segmental LV velocities were maintained indicating the potential of elevated ECV to identify regional diffuse fibrosis not visible by LGE which was associated with impaired regional LV function Regionally elevated ECV negatively impacted myocardial velocities. The association of elevated regional ECV with reduced myocardial velocities independent of LVEF suggests a structure-function relationship between altered ECV and segmental myocardial function in NICM.