Long-Term Electrocardiographic Follow-Up of a Patient with Light-Chain Cardiac Amyloidosis

Abstract

Amyloid light-chain (AL) cardiac amyloidosis can cause restrictive cardiomyopathy, which has a poor prognosis. Although electrocardiography (ECG) is useful for its diagnosis and management, there are few reports on the long-term follow-up of electrocardiographic changes in affected patients. The present patient was a 62-year-old woman who visited our hospital for assessment of palpitations and lower leg edema. A chest radiograph showed cardiac enlargement, and ECG revealed sinus rhythm, first-degree atrioventricular block, low QRS voltage in the limb leads and a pseudo-myocardial infarction pattern in the precordial leads. Echocardiography revealed left ventricular hypertrophy with systolic and diastolic dysfunction. Immunoelectrophoresis demonstrated M-protein (IgGλ), and bone marrow biopsy suggested IgGλ-type plasmacytoma. Myocardial biopsy findings were compatible with cardiac amyloidosis. On the basis of these findings, we diagnosed AL cardiac amyloidosis. Melphalan-prednisolone (MP) therapy was started in conjunction with treatment for non-sustained ventricular tachycardia and congestive heart failure. Two years and 4 months later, the sinus rhythm converted to atrial tachycardia. At a follow-up examination at 4 years and 8 months, right branch block appeared. After that, intraventricular conduction worsened, and the low voltage in the limb leads was not observed. Seven years after diagnosis, she was hospitalized for treatment of pneumonia and heart failure with tachycardia. On the seventh day of hospitalization, heart rhythm changed to atrial stand-still with escaped ventricular rhythm and she died of cardiac arrest. These ECG changes are valuable information regarding the pathophysiological changes that occur in AL cardiac amyloidosis.