Cardiac Involvement in Fukuyama-type Congenital Muscular Dystrophy

Abstract

Fukuyama-type congenital muscular dystrophy is an autosomal recessive disorder characterized by generalized skeletal muscle weakness and hypotonia from early infancy and by mental retardation. Little is known about cardiac involvement in patients with Fukuyama-type congenital muscular dystrophy. This study evaluated whether cardiac involvement exists in patients with Fukuyama-type congenital muscular dystrophy. We evaluated left ventricular function using M-mode and Doppler echocardiography in 34 patients with Fukuyama-type congenital muscular dystrophy. The age ranged from 6 months to 30 years (median: 6 years). A total of 64 recordings were analyzed. Left ventricular dimensions and parameters of systolic function measured included left ventricular end-diastolic dimension, left ventricular fractional shortening, left ventricular wall thickness, and the mean velocity of circumferential fiber shortening and end-systolic wall stress relationship. Left ventricular end-diastolic dimension z score >2 was observed in 2 patients (6%). Left ventricular fractional shortening <0.28 and/or reduced mean velocity of circumferential fiber shortening in the mean velocity of circumferential fiber shortening-end-systolic wall stress relationship were observed in 16 patients (47%). A significant correlation between age and left ventricular fractional shortening was observed, and left ventricular fractional shortening decreased with age. Of 12 patients >15 years of age, 10 (83%) showed decreased left ventricular systolic function. Left ventricular fractional shortening was normal in most patients <10 years of age, and it was reduced in most patients >15 years of age. Five patients died of heart failure or respiratory problems, and a histologic examination confirmed the presence of myocardial fibrosis. No patients showed increased left ventricular wall thickness or a conduction abnormality on electrocardiograms. Cardiac involvement exists in patients with Fukuyama-type congenital muscular dystrophy and becomes evident in older children in the second decade. A cardiac evaluation, including echocardiograms and subsequent follow-up, is important, especially in patients >10 years of age.