Cardiac Assessment in Duchenne and Becker Muscular Dystrophies

Abstract

Mutations in the dystrophin gene cause Duchenne and Becker muscular dystrophies. In addition to muscle disease, there nearly always is an associated cardiomyopathy in Duchenne or Becker muscular dystrophy. In these muscular dystrophies, the severity of cardiomyopathy and congestive heart failure may not parallel the severity of skeletal muscle disease. Loss of normal dystrophin function in the heart produces four-chamber dilation and reduction in left ventricular function that develop after the onset of muscle weakness. Arrhythmias affecting both atrial and ventricular rhythms occur and may be life threatening. The degree to which hypoventilation and pulmonary dysfunction are present also directly affect cardiac function in muscular dystrophy. Care guidelines recently were issued to outline surveillance and treatment strategies for the younger patient with Duchenne muscular dystrophy. Herein, we review those guidelines, and additionally, provide recommendations for monitoring and treating cardiac disease in the populations of advanced Duchenne and Becker muscular dystrophies.

Management of Cardiac Involvement Associated With Neuromuscular Diseases: A Scientific Statement From the American Heart Association

“…13 Although this risk increases with age, with up to 70% developing symptomatic HF by age 40,19 disease progression is much less predictable than for DMD. 20 Because of the underlying pathogenesis (myocyte disruption attributable to abnormal dystrophin protein), conduction system involvement is not a feature of DMD and BMD as it is with many other NMDs. Although the risk of tachyarrhythmia in DMD and BMD generally increases with the severity of ventricular dysfunction, tachyarrhythmias, including supraventricular tachycardia, can also occur with normal ejection fraction (EF).…”

“…e218 resynchronization therapy may be an option, particularly in DMD or BMD. 20,328 To date, there are only a few case reports of benefit with cardiac resynchronization therapy in DMD, 329,330 BMD, 331 and DM1. …”

Focal but reversible diastolic sheet dysfunction reflects regional calcium mishandling in dystrophicmdxmouse hearts

“…Dystrophin is a key component of the transmembrane dystrophin-associated glycoprotein complex that bridges intracellular actin and the extracellular matrix to facilitate mechanical coupling and signal transduction and to stabilize the sarcolemma membrane (25,56,66). Our previous work using magnetic resonance (MR) tagging uncovered occult abnormal wall strains occurring regionally at the base of heart in DMD patients (3).…”

Na+–H+exchanger and proton channel in heart failure associated with Becker and Duchenne muscular dystrophies

“…As mentioned earlier, due to the importance and high incidence of DCM in muscular diseases, early assessment and treatment of HF in DMD and BMD were recommended (Romfh and McNally 2010). It has therefore recently been highly recommended to monitor cardiac disease early in childhood in DMD patients and treat them as soon as possible (Romfh and McNally 2010).…”

“…It has therefore recently been highly recommended to monitor cardiac disease early in childhood in DMD patients and treat them as soon as possible (Romfh and McNally 2010). Finally, without any doubt, the life expectancy of DMD and BMD patients is largely dependent on the severity of DCM (Blain and Straub 2011).…”