A 66-year-old African American software engineer with hypertension (diagnosed 2 years ago on his annual exam) is referred to your clinic with newly diagnosed heart failure with preserved ejection fraction (HFpEF). His echocardiogram shows biatrial enlargement, concentric left ventricular hypertrophy (LVH) with a wall thickness of 1.6 cm, and evidence of diastolic dysfunction. His blood pressure has been well controlled on a low dose of one antihypertensive medication, and he has had regular medical checkups for his entire life.
What is the most likely etiology of this patient's LVH?
The correct answer is: C. Cardiac amyloidosis.
The correct answer is Choice C: Cardiac amyloidosis. It is important to note that echocardiographic evidence of increased left ventricular wall thickness is not always LVH. Conditions that cause myocyte hypertrophy such as hypertrophic cardiomyopathy, aortic stenosis, and uncontrolled hypertension can cause LVH. By contrast, infiltrative cardiomyopathies such as cardiac amyloidosis and inherited storage diseases, such as Fabry Disease, can result in infiltration within the myocardium that results in increased left ventricular wall thickness. Standard 2D echocardiography alone can only provide measurements of left ventricular wall thickness, and additional information is required to determine if the increased left ventricular wall thickening is truly LVH versus an infiltrative disorder.
Choices A and B are incorrect. Hemochromatosis and cardiac sarcoidosis do not usually cause severe LVH. Hemochromatosis in later stages can result in a dilated cardiomyopathy. Cardiac sarcoidosis can also result in a dilated cardiomyopathy, with some regional wall motion abnormalities related to prior areas of inflammation and fibrosis. Cardiac MRI can be a useful diagnostic modality for both of these conditions. Choice D is also incorrect. Mild LVH can be seen in endurance athletes, and usually reverses after cessation of endurance training; however, the degree of hypertrophy seen in this case (a wall thickness of 1.6 cm) is pathologic, and outside what would be expected from endurance training alone. LVH can be seen in hypertension; however, this degree of LVH would be very unusual in a patient with well controlled hypertension. Thus, Choice E is incorrect.
Kittleson MM, Maurer MS, Ambardekar AV, et al. Cardiac Amyloidosis: Evolving Diagnosis and Management: A Scientific Statement From the American Heart Association. Circulation 2020;142:e7-e22.
Witteles RM, Bokhari S, Damy T, et al. Screening for Transthyretin Amyloid Cardiomyopathy in Everyday Practice. JACC Heart Fail 2019;7:709-16.