心脏核磁共振在心肌淀粉样变中的诊断价值

Value of cardiac magnetic resonance imaging for the diagnosis of cardiac amyloidosis

目的 研究心内膜心肌活检（EMB）确诊心肌淀粉样变性（CA）患者的临床和心脏核磁共振（CMR）特点，明确CMR在CA中的诊断价值。方法回顾性分析2006年9月至2010年12月期间EMB确诊CA并行CMR检查患者的临床表现、心电图、心脏超声及CMR结果。结果共18例患者通过EMB确诊为CA，其中5例进行了CMR检查。5例患者均有心力衰竭的临床表现以及心电图改变，心脏超声示左心室向心性肥厚，心肌回声增强、颗粒样回声，左心房扩大，限制性舒张功能不全。CMR主要表现为左心室壁增厚，室间隔增厚明显，双房均增大，心室收缩功能正常或减低，舒张功能均不同程度受限，部分伴有心包及胸腔积液，延迟钆显像（LGE）呈不同程度的延迟强化，位于左心室心内膜下或心肌弥漫性延迟强化，部分患者强化可为线样、颗粒样或斑片状。随病程延长，心肌LGE程度及范围有更严重的趋势，与心电图改变一致。结论CMR有助于CA诊断及病情判断，为CA重要的无创检查方法之一。临床怀疑CA患者可早期进行CMR检查，特别是在没有开展EMB检查的医院。

Objective To observe the clinical features and cardiac magnetic resonance imaging （CMR） characteristics of patients with endomyocardial biopsy（EMB）-proven cardiac amyloidosis （CA）. Methods EMB proven CA patients underwent CMR examination from September 2006 to December 2010 were included. The findings of clinical manifestation, electrocardiogram, echocardiography and CMR were analyzed. Results Among the 18 patients with EMB verified CA, 5 patients underwent CMR. All 5 patients had heart failure symptoms and electrocardiogram was abnormal. Echzcardiogram showed concentric left ventricular hypertrophy, granular appearance of the myocardium, left atrial enlargement and moderate to severe left ventricular diastolic dysfunction. CMR revealed increased thickness of the left ventricular wall （especially at the inter-ventricular septum）, enlarged bilateral auricle, restricted left ventricular filling with normal or mild to moderate reduced systolic function. Pleura1 and pericardial effusions were observed in 2 patients. Abnormal late gadolinium enhancement （LGE） was detected in all 5 patients. CMR revealed different patterns of LGE. Left ventricular global subendocardial delayed gadolinium enhancement or transmural delayed gadolinium enhancement were found, and patients also showed line-, granular- or patchy- like enhancement. The degree and range of LGE paralleled the disease course and were consistent with electrocardiogram changes. Conclusions As a noninvasive diagnostic tool, CMR is valuable in the diagnosis of CA. For patients with clinical suspicion of CA, CMR could be a helpful diagnostic tool, especially in the hospitals where EMB is not available.