Cardiac Amyloidosis

Excerpt

Amyloidosis is a systemic infiltrative disease characterized by the extracellular deposition of insoluble proteins. The most prevalent variant is amyloid light chain (AL) amyloidosis, affecting more than ten people per million per year. The protein fibers in the amyloid light chain consist of monoclonal light chains. The other form, amyloid transthyretin (ATTR) amyloidosis, is characterized by the deposition of a normal or mutated form of transthyretin proteins. Cardiac involvement has been reported in both variants of amyloidosis.

Cardiac amyloidosis is the most common type of restrictive cardiomyopathy, the other two being cardiac sarcoidosis and cardiac hemochromatosis. The infiltrative cardiomyopathies characteristically have a depressed diastolic function in the presence of a non-dilated left ventricle (LV). Irrespective of the etiology, cardiac amyloidosis is the leading cause of mortality in patients with systemic amyloidosis.

Cardiac amyloidosis may manifest primarily or be discovered incidentally in patients with other signs and symptoms of systemic amyloidosis. Delay in diagnosis is common and may lead to a delay in the initiation of the treatment. Cardiac involvement in systemic amyloidosis carries prognostic value and is the most critical determinant of survival in this disease.