Khalid Umair, Awar Omar, Verstovsek Gordana, Cheong Benjamin, Yellapragada Sarvari Venkata, Jneid Hani, Deswal Anita, Virani Salim S
Baylor College of Medicine, Houston, Texas.
St. Luke's Episcopal Hospital, Houston, Texas.
Methodist Debakey Cardiovasc J. 2015 Jan-Mar;11(1):53-8. doi: 10.14797/mdcj-11-1-53.
Amyloidosis is a rare, multisystem disease characterized by deposition of fibrils in extracellular tissue involving kidney, liver, heart, autonomic nervous system, and several other organs. This report discusses a 75-year-old male who presented with worsening dyspnea on exertion, orthopnea, and lower-extremity edema. On physical exam, he had elevated jugular venous pressure and lower-extremity edema. Electrocardiogram depicted low voltage in limb leads and a prolonged PR interval. Echocardiogram revealed left ventricular hypertrophy, severe biatrial dilatation, and restrictive filling physiology. Coronary angiography showed absence of significant epicardial coronary artery disease. On right heart catheterization, a "dip-and-plateau sign" was noted on right ventricular pressure tracings. A diagnosis of cardiac amyloidosis was considered, but a complete hematology work-up for systemic amyloidosis was negative. Cardiac magnetic resonance imaging was pursued, showing delayed gadolinium enhancement, and this ultimately led to the myocardial biopsy confirming the diagnosis of isolated cardiac amyloidosis. Further genetic analyses confirmed isolated cardiac amyloid caused by mutant transthyretin protein (Val-122-Ile). Isolated cardiac amyloidosis is an extremely rare entity, and diagnosis may be difficult despite the use of multimodality imaging. If the index of suspicion is high, then myocardial biopsy should be considered.
淀粉样变性是一种罕见的多系统疾病，其特征是原纤维在细胞外组织中沉积，累及肾脏、肝脏、心脏、自主神经系统和其他几个器官。本报告讨论了一名75岁男性，他出现劳力性呼吸困难加重、端坐呼吸和下肢水肿。体格检查时，他有颈静脉压升高和下肢水肿。心电图显示肢体导联低电压和PR间期延长。超声心动图显示左心室肥厚、严重双房扩大和限制性充盈生理。冠状动脉造影显示无明显的心外膜冠状动脉疾病。右心导管检查时，右心室压力描记图上出现“下倾-高原征”。考虑诊断为心脏淀粉样变性，但系统性淀粉样变性的完整血液学检查结果为阴性。进行了心脏磁共振成像，显示钆延迟强化，这最终导致心肌活检确诊为孤立性心脏淀粉样变性。进一步的基因分析证实孤立性心脏淀粉样变性由突变的转甲状腺素蛋白（Val-122-Ile）引起。孤立性心脏淀粉样变性是一种极其罕见的疾病，尽管使用了多模态成像，诊断仍可能困难。如果怀疑指数较高，则应考虑进行心肌活检。
