Cardiac Involvement in Four Patients with Immunoglobulin Light-Chain Systemic Amyloidosis

In immunoglobulin light-chain (L) amyloidosis the cause of death is most commonly due to cardiac involvement. Cardiac amyloidosis is frequently diagnosed by postmortem examination. There are many reports of diagnoses of cardiac amyloidosis established by autopsy of cardiac tissue. We report four patients whom we could diagnose as having cardiac amyloidosis by echocardiogram and electrocardiogram. They were referred to our hospital because of congestive heart failure. All patients had thickened ventricular walls, increased myocardial echogenicity, and normal ventricular chamber size on echocardiogram. Our 4 cases showed low voltage and pseudoinfarction pattern on electrocardiogram. Biopsies from the myocardium, rectal mucosa and/or abdominal wall revealed extracellular deposition of amyloid in all cases. Two cases were associated with myeloma and the other two cases were primary amyloidosis. Cardiac involvement from amyloid light-chain (AL) amyloidosis is rapidly fatal. Unfortunately, the diagnosis of AL amyloidosis is often delayed. AL amyloidosis should be considered as a cause of congestive heart failure and requires further investigation.