A 60-year-old previously healthy woman is evaluated for progressively worsening fatigue, exertional dyspnea, and lower extremity swelling. The patient also bruises easily and was recently found to have significant proteinuria. She takes no medications but has a 10-pack-year smoking history and drinks 2 or 3 glasses of wine daily. Temperature is 37.1 C (98.8 F), blood pressure is 130/70 mm Hg, pulse is 80/min, and respirations are 14/min. Examination shows jugular venous distension. The lungs are clear to auscultation. Echocardiography shows small pericardial effusion and concentric thickening of the ventricular walls with diastolic dysfunction. Ventricular chamber dimensions are normal. Which of the following is the most likely cause of this patient's symptoms?

Question

A 60-year-old previously healthy woman is evaluated for progressively worsening fatigue, exertional dyspnea, and lower extremity swelling.  The patient also bruises easily and was recently found to have significant proteinuria.  She takes no medications but has a 10-pack-year smoking history and drinks 2 or 3 glasses of wine daily.  Temperature is 37.1 C (98.8 F), blood pressure is 130/70 mm Hg, pulse is 80/min, and respirations are 14/min.  Examination shows jugular venous distension.  The lungs are clear to auscultation.  Echocardiography shows small pericardial effusion and concentric thickening of the ventricular walls with diastolic dysfunction.  Ventricular chamber dimensions are normal.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d32e_33e2_bc81_b599376c865c_MD0003_00 This patient's fatigue, exertional dyspnea, and lower extremity swelling in the absence of pulmonary edema are consistent with right-sided heart failure, the predominant manifestation of restrictive cardiomyopathy (evidenced by thickened ventricular walls and diastolic dysfunction on echocardiography). Systemic infiltrative disease is a common cause of restrictive cardiomyopathy; this patient's concomitant easy bruising and large proteinuria suggest underlying amyloidosis. Amyloidosis involves the deposition of insoluble protein fibrils in various organs and tissues throughout the body. In addition to the heart, kidneys, and skin, the liver (manifesting as hepatomegaly) and nervous system (manifesting as peripheral and autonomic neuropathy) are commonly affected. Primary amyloid (amyloid light chain [AL]) results from overproduction of protein fibrils by a clonal line of plasma cells, but amyloid proteins may also accumulate related to age (amyloid transthyretin [ATTR]) or secondary to chronic disease (eg, rheumatoid arthritis) (amyloid A [AA]). Cardiac involvement of amyloid (common with AL and ATTR) typically leads to restrictive cardiomyopathy early in the course and can progress to dilated cardiomyopathy over time. Conduction abnormalities (eg, atrioventricular block) may also occur. The diagnosis is confirmed by endomyocardial biopsy or biopsy of other tissue (eg, abdominal fat pad) in the appropriate clinical setting. (Choice A) Alcohol-related heart disease typically manifests as dilated cardiomyopathy with impaired left ventricular systolic function. Restrictive cardiomyopathy is not known to occur due to alcohol abuse. (Choice C) Like restrictive cardiomyopathy, constrictive pericarditis presents with symptoms of predominantly right-sided heart failure. However, there is typically a history of pericarditis; easy bruisability, proteinuria, and ventricular wall thickening on echocardiogram are not expected. (Choices D and E) Hemochromatosis and sarcoidosis are other infiltrative diseases that can initially cause restrictive and, later, dilated cardiomyopathy. Hemochromatosis involves iron deposition in various tissues and, in addition to cardiomyopathy, can cause cirrhosis, diabetes mellitus (pancreatic iron deposition), arthropathy, and hypogonadism (pituitary iron deposition). Sarcoidosis involves granulomatous infiltration of various tissues and most commonly involves the lungs and lymph nodes; the heart is less commonly affected. Easy bruisability and proteinuria would be unusual in both diseases. Educational objective: Amyloidosis is a disease involving deposition of insoluble protein fibrils in various organs and tissues throughout the body. Cardiac involvement is common, typically manifesting as restrictive cardiomyopathy that may later progress to dilated cardiomyopathy. Other commonly affected organs include the liver, kidneys, skin, and nervous system. The diagnosis is confirmed by tissue biopsy (eg, abdominal fat pad). References: Current state of cardiac amyloidosis. (http://www.ncbi.nlm.nih.gov/pubmed/23324855)

A 60-Year-Old Previously Healthy Woman Is Evaluated for Progressively Worsening