Lewars Jennaire, Wazir Hersh, Gordon Brandon, Faluyi Uyi, Girgis Yousry
Internal Medicine, Saint James School of Medicine, Chicago, USA.
Medicine, All Saints University College of Medicine, Toronto, CAN.
Cureus. 2021 Apr 21;13(4):e14608. doi: 10.7759/cureus.14608.
Amyloidoses are a family of inherited or acquired disorders characterized by the deposition of insoluble extracellular protein fibrils in various organs and tissues, thereby impairing their function. Amyloidoses are typically misfolded proteins, and on rare occasions, can deposit in the myocardium resulting in an infiltrative/restrictive cardiomyopathy. Restrictive cardiomyopathy is an underdiagnosed cause of congestive heart failure (CHF) with preserved ejection fraction, atrial and ventricular arrhythmias along with conduction defects. In elderly patients, as with this study, cardiac amyloidosis most often results from abnormalities in the liver protein transthyretin (TTR), a thyroxine and retinol-retinol binding complex transporter in blood. Mutated serum TTR results in familial systemic amyloidosis, whereas wild-type TTR results in senile cardiac amyloidosis predominantly seen in elderly males. Scintigraphy, a common non-invasive method used to facilitate early diagnosis of cardiac amyloidosis was the method used in this study. However, the gold standard for definitive diagnosis of cardiac amyloidosis is endomyocardial biopsy (EMB). Besides organ transplant, which is rarely done, therapy for cardiac amyloidosis is mainly aimed at symptomatic and supportive care. Plenty of evidence has shown that the left ventricular ejection fraction (LVEF) in patients with restrictive cardiomyopathy is usually preserved. However, in this study, we review the unique case of an 82-year-old male who was diagnosed with isolated cardiac amyloidosis with severe systolic dysfunction (decreasedLVEF), the methods used to establish the diagnosis, as well as the therapeutic interventions.
淀粉样变性是一类遗传性或获得性疾病，其特征是不溶性细胞外蛋白原纤维沉积在各种器官和组织中，从而损害其功能。淀粉样变性通常是错误折叠的蛋白质，在极少数情况下，可沉积在心肌中，导致浸润性/限制性心肌病。限制性心肌病是射血分数保留的充血性心力衰竭（CHF）、房性和室性心律失常以及传导缺陷的一个未被充分诊断的原因。在老年患者中，如本研究中的患者，心脏淀粉样变性最常由肝脏蛋白转甲状腺素蛋白（TTR）异常引起，TTR是血液中的一种甲状腺素和视黄醇-视黄醇结合复合物转运蛋白。血清TTR突变导致家族性系统性淀粉样变性，而野生型TTR导致主要见于老年男性的老年性心脏淀粉样变性。闪烁扫描是一种用于促进心脏淀粉样变性早期诊断的常见非侵入性方法，本研究中使用的就是这种方法。然而，心脏淀粉样变性确诊的金标准是心内膜心肌活检（EMB）。除了很少进行的器官移植外，心脏淀粉样变性的治疗主要针对症状性和支持性护理。大量证据表明，限制性心肌病患者的左心室射血分数（LVEF）通常保留。然而，在本研究中，我们回顾了一例82岁男性被诊断为孤立性心脏淀粉样变性伴严重收缩功能障碍（LVEF降低）的独特病例、用于确诊的心内膜心肌活检（EMB）方法，以及治疗干预措施。
