The incidence and evolution of cardiomyopathy in Duchenne muscular dystrophy

Cardiac assessment in childhood carriers of Duchenne and Becker muscular dystrophies

“…On ECG, the typical features include an anterior QRS pattern, which is thought to reflect myocardial fibrosis that begins in the posterobasal portions of the left ventricle, then the posterior papillary muscle, the interventricular septum and rarely the right ventricle [8,12]. Lengthening of the QT segment and conduction abnormalities such as tachyarrhythmia and bundle branch block are associated with the hypertrophic or dilated cardiomyopathy seen in XLD [5,6,13]. Clinically detectable cardiomyopathy does not usually become apparent until after 10 years of age and is reported to affect approximately 50% of boys by 18 years of age [13].…”

“…Lengthening of the QT segment and conduction abnormalities such as tachyarrhythmia and bundle branch block are associated with the hypertrophic or dilated cardiomyopathy seen in XLD [5,6,13]. Clinically detectable cardiomyopathy does not usually become apparent until after 10 years of age and is reported to affect approximately 50% of boys by 18 years of age [13]. There appears to be a progression through a stage of cardiac hypertrophy to dilated cardiomyopathy [13].…”

“…Clinically detectable cardiomyopathy does not usually become apparent until after 10 years of age and is reported to affect approximately 50% of boys by 18 years of age [13]. There appears to be a progression through a stage of cardiac hypertrophy to dilated cardiomyopathy [13]. In BMD cardiac involvement follows a similar pattern, often with later onset, although patients may present at an early age with significant cardiomyopathy despite minimal skeletal muscle manifestations [9].…”

Evolution of cardiac abnormalities in Becker muscular dystrophy over a 13-year period

“…We suppose that LBBB, and therefore the risk of developing lethal rhythmical disorders, only occurs in the end-stage cases of cardiac involvement where the dystrophic process has destroyed the whole heart. Nigro et al have used the QT/PQs ratio on ECG to detect early cardiac involvement [29][30][31][32][33]. We were not able to confirm this observation since this feature was only present in three of 12 patients with normal findings at echocardiography.…”

Upper arm and cardiac magnetic resonance imaging in Duchenne muscular dystrophy

“…Individuals with DMD develop cardiomyopathy by age 18 years 7. Whereas corticosteroids and supportive measures have improved overall prognosis and lifespan, cardiomyopathy continues to be relentlessly progressive and has become a major cause of death 8.…”