A 67-year-old woman comes to the physician because of edema and shortness of breath. She reports that the edema has been present for approximately 3-4 months and involves her lower extremities. The shortness of breath occurs with minimal exertion and occasionally at rest. She denies chest pain or pressure, cough, and fever. She has history of breast cancer diagnosed 12 years ago that was treated with mastectomy, chemotherapy, and chest wall radiation therapy. Her medications include aspirin, fish oil, and simvastatin. Her blood pressure is 115/70 mm Hg, pulse is 62/min, and BMI is 27 kg/m². The patient is in no acute distress. Her lungs are clear bilaterally. There is a normal S1 and S2 with a 2/6 apical murmur that radiates to the axilla. She has 3+ pitting edema below the knees bilaterally. Her electrocardiogram is shown below. A transthoracic echocardiogram shows a normal left ventricular cavity size, a left ventricular ejection fraction of 70%, biatrial dilatation, severe left ventricular hypertrophy, and moderate mitral regurgitation. Which of the following is the most likely additional finding in this patient?

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11ec193a_973a_98d3_853d_19cca0ccc664_MD0002_00 This patient's presentation is most consistent with an infiltrative cardiomyopathy. Infiltrative etiologies such as sarcoidosis and amyloidosis most commonly present with increased left ventricular mass on echocardiogram and low QRS voltage (< 5 mm in limb leads and < 10 mm in precordial leads) on ECG (abnormal mass/voltage ratio). Left ventricular wall thickening eventually leads to diastolic dysfunction, right ventricular dysfunction, and biatrial enlargement. The increased left ventricular mass and thickening may be misdiagnosed as left ventricular hypertrophy (LVH) on echocardiography. However, significant LVH from conditions such as hypertension, aortic stenosis, or hypertrophic cardiomyopathy usually causes increased QRS voltage on ECG with a "strain" pattern. Conditions that decrease QRS voltage, such as pericardial effusion, do not usually cause LVH. Patients typically present with lower extremity edema, shortness of breath, orthostatic hypotension, and conduction abnormalities. The most common renal manifestation of AL and AA amyloidosis is heavy proteinuria and associated glomerular deposits. The diagnosis of amyloidosis is confirmed when amyloid deposits are seen with Congo red stain on endomyocardial biopsy or tissue biopsy of other involved organs. Treatment is largely supportive with a median survival < 1 year in patients with cardiac amyloidosis. (Choice A) An ascending aortic aneurysm is not typically associated with amyloidosis or sarcoidosis. However, left ventricular aneurysms can be seen in sarcoidosis. (Choice B) Cardiac amyloid is associated with intracardiac thrombi that can lead to ischemic stroke, but is usually not associated with carotid artery occlusion. (Choice C) Amyloidosis can cause pulmonary nodules (amyloidomas), but they are usually not cavitary. Cavitary lesions are more commonly seen in tuberculosis. (Choice D) Hyperthyroidism is usually associated with high-output heart failure and atrial fibrillation. Hypothyroidism can sometimes cause large pericardial effusions that lead to low voltage on ECG. Educational objective: Infiltrative cardiomyopathies (most commonly amyloid and sarcoid) are suggested by a mass/voltage discrepancy on echocardiogram and electrocardiogram. Amyloid cardiomyopathy is usually seen in AL amyloidosis and is associated with other systemic manifestations such as heavy proteinuria. Diagnosis is confirmed by tissue biopsy and treatment is largely supportive. __________ References: Infiltrative cardiovascular diseases: cardiomyopathies that look alike. (http://www.ncbi.nlm.nih.gov/pubmed/20413025) Cardiac amyloidosis: a practical approach to diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/22017778)

A 67-Year-Old Woman Comes to the Physician Because of Edema