Early left ventricular regional contractile impairment in chronic mitral regurgitation occurs in a consistent, heterogeneous pattern.
Early left ventricular regional contractile impairment in chronic mitral regurgitation occurs in a consistent, heterogeneous pattern.
复制标题
慢性二尖瓣反流的早期左心室区域收缩障碍以一致的、异质的模式发生。
DOI：
10.1016/j.jtcvs.2014.05.088
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Pasque,MichaelK
中科院分区：
文献类型：
--
作者：
Maniar,HershS;Brady,BeckahD;Lee,Urvi;Cupps,BrianP;Kar,Julia;Wallace,KathleenM;Pasque,MichaelK
目的：无症状慢性二尖瓣返流（MR）患者的临床指南使用射血分数（EF）来触发外科转诊。我们假设，EF是不够敏感，以检测最早的收缩性损伤慢性MR和损伤与慢性MR是不是全球性的，但异质性，发生区域和可预测的，全球左心室（LV）功能障碍发病前，通过超声心动图的LVEF正常的慢性MR和15例进行心脏磁共振成像与组织标记。多个应变参数与正常人应变数据库的点特异性比较（在15，300个LV网格点）允许患者特异性区域收缩功能的标准化。数据被映射到患者特定的三维几何形状和平均跨越6 LV regions.ResultsGlobal LV纵向和圆周心肌应变正常的所有15例MR与正常对照组相比（P> .05）。尽管保留了整体功能，但与其他LV区域相比，前间隔和后间隔的收缩功能明显较差（分别为P= 0.003和P = 0.035）。收缩过度的地区（侧壁）出现补偿（P= .002）减少间隔收缩功能，掩蔽损伤检测的全球indexs.ConclusionsThe最早的收缩损伤MR患者中看到的是异质性和一致的分布沿着LV隔膜。代偿反应包括其他区域的过度收缩。这些数据表明，与其依赖于无法检测早期损伤的全局LV收缩指标，患者可能更好地通过使用高分辨率的区域收缩功能指标对“前哨”LV区域（LV间隔）进行直接监测。
ObjectivesThe clinical guidelines for asymptomatic patients with chronic mitral regurgitation (MR) use the ejection fraction (EF) to trigger surgical referral. We hypothesized that the EF is not sensitive enough to detect the earliest contractile injury in chronic MR and that the injury associated with chronic MR is not global but heterogeneous, occurring regionally and predictably, before the onset of global left ventricular (LV) dysfunction.MethodsFifteen patients with chronic MR and normal LVEF by echocardiography underwent cardiac magnetic resonance imaging with tissue tagging. Point-specific comparisons (at 15,300 LV grid points) of multiple strain parameters to a normal human strain database allowed normalization of patient-specific regional contractile function. Data were mapped over patient-specific 3-dimensional geometry and averaged across 6 LV regions.ResultsGlobal LV longitudinal and circumferential myocardial strains were normal for all 15 patients with MR compared with normal controls (P> .05). Despite preserved global function, the anteroseptum and posteroseptum demonstrated significantly worse contractile function compared with other LV regions (P= .003 andP= .035, respectively). Hypercontractile regions (lateral walls) appeared to compensate (P= .002) for the reduced septal contractile function, masking injury detection by global indexes.ConclusionsThe earliest contractile injury seen in patients with MR is heterogeneous and consistently distributed along the LV septum. Compensatory responses include hypercontractility of other regions. These data suggest that rather than relying on global LV contractile metrics, which cannot detect early injury, patients might be better served by undergoing directed surveillance of “sentinel” LV regions (LV septum) with high-resolution metrics of regional contractile function.