Department of Cardiology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
Department of Cardiology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
J Cardiol. 2023 Feb;81(2):236-243. doi: 10.1016/j.jjcc.2022.09.012. Epub 2022 Sep 28.
Electron microscopy enables a finely detailed analysis of ultra-structural features, and hence, it generally has an added diagnostic value to light microscopy alone. However, no studies have verified the additional diagnostic value of electron microscopic examination in patients with suspected non-ischemic cardiomyopathy.
A total of 294 consecutive patients with non-ischemic cardiomyopathy who underwent endomyocardial biopsy were prospectively enrolled. Patients were divided into three groups according to left ventricular morphology assessed using echocardiography. Myocardial specimens were collected from the right ventricular septum and examined by light microscopy. Electron microscopy was performed subsequently to evaluate the additional diagnostic value.
Altogether, 294 patients were analyzed, including 160 (55 %), 96 (33 %), and 35 (12 %) patients who were diagnosed with primary, secondary, and unclassified cardiomyopathy, respectively. In patients with dilated cardiomyopathy-like morphology, the detection rate of disease-specific histological findings was relatively low compared to that in patients with other cardiac morphologies. The additional diagnostic value of electron microscopy was observed in eight patients, including five with Fabry disease, one with cardiac amyloidosis, one with mitochondrial cardiomyopathy, and one with triglyceride deposit cardiomyovasculopathy. Among the 18 cardiac amyloidosis cases, electron microscopy detected amyloid fibrils in all patients, whereas light microscopy could not detect amyloid deposition in 1 patient. Among one of five patients with Fabry disease, light microscopy did not show obvious vacuolated cardiomyocytes, but zebra bodies were detected by electron microscopy, leading to the diagnosis of cardiac Fabry disease. The diagnostic value of electron microscopic examination in patients with cardiac sarcoidosis was not observed.
The additional diagnostic value of electron microscopy was observed in patients with secondary cardiomyopathy, in whom light microscopy did not show disease-specific histological findings. Electron microscopy should be performed in cases where secondary cardiomyopathy is strongly suspected with no disease-specific findings by light microscopy.
电子显微镜能够对超微结构特征进行精细分析，因此，它通常对单独的光镜检查具有附加的诊断价值。然而，目前还没有研究证实电子显微镜检查在疑似非缺血性心肌病患者中的附加诊断价值。
共前瞻性纳入 294 例接受心肌内膜活检的非缺血性心肌病患者。根据超声心动图评估的左心室形态将患者分为三组。采集右室间隔心肌标本，行光镜检查。随后进行电子显微镜检查，以评估附加诊断价值。
共分析了 294 例患者，其中 160 例（55%）、96 例（33%）和 35 例（12%）患者分别诊断为原发性、继发性和未分类心肌病。在扩张型心肌病样形态的患者中，与其他心脏形态的患者相比，疾病特异性组织学发现的检出率相对较低。电子显微镜检查在 8 例患者中具有附加诊断价值，包括 5 例法布里病、1 例心脏淀粉样变性、1 例线粒体心肌病和 1 例甘油三酯沉积性心肌病。在 18 例心脏淀粉样变性病例中，电子显微镜均检测到淀粉样纤维，而光镜检查未能在 1 例患者中检测到淀粉样沉积。在 5 例法布里病患者中，1 例光镜下未见明显空泡化的心肌细胞，但电子显微镜下检测到斑马体，从而诊断为心脏法布里病。电子显微镜检查在心脏结节病患者中的诊断价值尚未观察到。
在光镜检查未显示特定疾病组织学发现的继发性心肌病患者中，观察到电子显微镜检查的附加诊断价值。在光镜检查无特定疾病发现但强烈怀疑为继发性心肌病的情况下，应进行电子显微镜检查。
