Long-term Electrocardiographic Follow-up in Patients with Light-chain Cardiac Amyloidosis.

Abstract

Amyloid light-chain (AL) cardiac amyloidosis is known to result in 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. The patient in the present case was a 62-year-old woman who visited our hospital due to palpitation 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 pseudomyocardial 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 implied IgGλ-type plasmacytoma. Myocardial biopsy findings were compatible with cardiac amyloidosis. Based on these findings, we diagnosed the patient with AL cardiac amyloidosis. Melphalan-prednisolone (MP) therapy was performed in conjunction with treatment for non-sustained ventricular tachycardia and congestive heart failure. Two years and four months later, the sinus rhythm converted to atrial tachycardia. At a follow-up examination at four years and eight months, right branch block appeared. Then degree of intraventricular conduction was worsened, and the low voltage of the limb leads was not observed. Seven years after the diagnosis, she was eventually hospitalized for the treatment of pneumonia and heart failure with tachycardia. On the seventh day of hospitalization, heart rhythm was changed to atrial stand-still with escaped ventricular rhythm and died of cardiac arrest. These ECG changes may provide valuable information regarding the pathophysiological changes that occur in AL cardiac amyloidosis.