Over the next year, he develops lower extremity edema, decreased exercise tolerance, and elevated liver enzymes. He has some chest pain, but an angiogram is negative for coronary artery disease. EKG shows low voltage in the limb leads. A repeat echo shows diastolic dysfunction, a small LV cavity, biatrial enlargement, and RV dilatation. The myocardium is easily seen and described as "granular and sparkling."
A year later, he develops exertional syncope. Two months later, he has sudden cardiac death. On autopsy, the heart is large and rubbery. The histopathology is shown below. The left slide is stained with H&E. The right slide is stained with alcian blue.
A slide of normal myocardium is shown below for comparison:
Challenge: What's your diagnosis?
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