Pilot Study of Cardiac MR in Patients With Muscular Dystrophy

Pilot Study of Cardiac Magnetic Resonance in Patients With Muscular Dystrophy

Muscular Dystrophy can affect the skeletal muscles and also the heart and breathing muscles, causing significant morbidity and mortality. As patients are now living longer, treatment of muscular dystrophies involves drugs that help improve heart function. However, better types of heart imaging studies are needed to understand how these treatments work. Researchers want to improve heart imaging to identify earlier indicators of heart dysfunction in muscular dystrophy patients and how these are changed by medical treatment. The new imaging indicators will also help identify candidates for entry into future clinical trials.

Cardiomyopathy causes significant morbidity and mortality in multiple forms of muscular dystrophy affecting children, including Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD) and subtypes of autosomal recessive limb-girdle muscular dystrophy (LGMD2). Pharmaceutical treatments for the cardiomyopathy of muscular dystrophy, including angiotensin-converting enzyme (ACE) inhibition and beta-adrenergic receptor blockade, afford significant benefit and demonstrate cardiac remodeling in clinical studies. Further studies are needed to identify and characterize more sensitive indicators of cardiac dysfunction in muscular dystrophy subjects to better stratify subjects for entry into clinical protocols.

Inclusion Criteria:

• Diagnosis of Duchenne, Becker, or Limb Girdle Muscular Dystrophy

Exclusion Criteria:

• Day-time users of continuous positive airway pressure (CPAP)
• Sip ventilator users
• Invasive ventilator dependent
• Pregnant minors or adults (when uncertain, participants will undergo urine testing) or lactating minors and adults
• Females who are nursing and who do not plan to discard breast milk for 24 hours
• Decompensated congestive heart failure (unable to lie flat during CMR)
• Impaired renal excretory function (calculated Glomerular Filtration Rate less than 30 milliliters/min)
• Contra-indications to Magnetic Resonance Imaging:
• Cardiac pacemaker or implantable defibrillator
• Cerebral aneurysm clip
• Neural stimulator
• Metallic ocular foreign body
• Any implanted device (i.e. insulin pump, drug infusion device)
• Claustrophobia
• Metal shrapnel or bullet
• Investigator assessment of inability to comply with protocol
• Unable/unwilling to lie still throughout the research procedure or who require sedation
• Persons with cognitive impairment