Rapid progression from hypertrophic cardiomyopathy to heart failure in a patient with Becker's muscular dystrophy

Abstract

We describe the case of a 17-year-old boy with Becker's muscular dystrophy (BMD) presenting with rapid progression from hypertrophic cardiomyopathy to heart failure within 2 years. Initial echocardiogram showed severe hypertrophy of left ventricle (LV) and right ventricle (RV) with normal chamber size, and preserved LV systolic function. Microscopic study of cardiac muscle obtained by endomyocardial biopsy of the interventricular septum showed severe hypertrophy of the muscle fibers and interstitial fibrosis. Follow-up echocardiogram 2 years after the first examination exhibited marked dilated LV and RV with severe LV global hypokinesia. Follow-up endomyocardial biopsy demonstrated increased interstitial cellular matrix. Immunohistochemical staining for dystrophin revealed significant loss of dystrophin along the sarcoplasmic membrane of the right biceps brachii muscle, compatible with BMD.

Cardiac involvement in Becker muscular dystrophy

“…Depending on the stage of the disease, echocardiography may show mild to severe myocardial thickening with normal size of the cardiac cavities and preserved systolic function (6,12,40). hCMP usually evolves into dCMP within varying periods of time, showing dilation of the cardiac cavities, global hypokinesia or other wall motion abnormalities, and normal or reduced systolic function (6,30).…”

“…hCMP usually evolves into dCMP within varying periods of time, showing dilation of the cardiac cavities, global hypokinesia or other wall motion abnormalities, and normal or reduced systolic function (6,30). Dilation becomes more prominent with age (7).…”

“…At an early stage of the disease, endomyocardial biopsy may show hypertrophy of the myocardiocytes and endocardial or interstitial fibrosis (6). In the later stages of the disease, endomyocardial fibrosis prevails (6).…”

“…In the later stages of the disease, endomyocardial fibrosis prevails (6). In addition, there may be cytoplasmic lipofuscinosis, focal lymphocytic infiltration, huge, pleomorphic, bizarre myonuclei of variable size, shape and staining, and focal necrosis (8,12,28,30,57).…”

“…Asymptomatic CI occurs in most cases, and up to one-third of patients develop dilative cardiomyopathy (dCMP) with concomitant heart failure (4,5). The degree of symptomatic CI in BMD varies greatly between no (or hardly any) cardiac abnormalities to severe arrhythmias, hypertrophic cardiomyopathy (hCMP), dCMP, heart failure or sudden cardiac death (3,6). The present review aims to give an overview of the recent developments and current knowledge about the clinical manifestations of CI, its pathophysiological background, diagnostic possibilities, the frequency of CI and the currently available therapeutic options for CI in BMD.…”