Specific heart muscle disease usually produces a dilated form of cardiomyopathy with impaired systolic function. Restrictive physiology is seen with amyloid, sarcoid, neoplasm, radiation, scleroderma, hemochromatosis, and eosinophilic endomyocardial disease, in which eosino-philia is usually present. Rarely, myocardial tuberculosis is present with restrictive features. Amyloid heart disease and EMF are usually considered examples of RCM, but when cardiac involvement is associated with multiple organ disease, they qualify as specific heart muscle disease (see Table 1).
Endomyocardial biopsy is often required but may not be helpful in patchy disease such as sarcoid. The presence of systemic disease of other organs, especially the liver, lymph nodes, and skin, which can be easily submitted to biopsy, assist in defining the underlying cause.
Amyloidosis causes deposition of specific proteins as insoluble fibrils in the extracellular space of several organs including the heart. The disease affects individuals in the fifth and sixth decade of life. The heart muscle is weakened and mainly right heart failure ensues in more than 40% of patients.