Amyloidosis and the heart: a comprehensive review.

Infiltration of the heart from insoluble protein deposits in amyloidosis often results in restrictive cardiomyopathy that manifests late in its course with heart failure and conduction abnormalities. While the rare primary amyloidosis-related heart disease has been well characterized, senile amyloidosis occurring in the seventh decade of life most frequently affects the heart. Early diagnosis of cardiac amyloidosis may improve outcomes but requires heightened suspicion and a systematic clinical approach to evaluation. Demonstration of tissue infiltration of biopsy specimens using special stains, followed by immunohistochemical studies and genetic testing, is essential in defining the specific protein involved. The therapeutic strategy depends on the characterization of the type of amyloid protein and extent of disease and may include chemotherapy, stem cell transplantation, and liver transplantation. Heart transplantation is controversial and is generally performed only at isolated centers.