heart imaging in children with muscular dystrophy

Conditions: Muscular Dystrophy

Summary: background: - muscular dystrophy can affect the muscles used for heart function and breathing. treatment usually involves drugs that help improve heart function. however, better types of heart imaging studies are needed to improve treatment of heart problems related to muscular dystrophy. better heart imaging methods are especially needed for children with muscular dystrophy. researchers want to test different heart imaging methods in children with muscular dystrophy. they will look at cardiac magnetic resonance imaging (mri) and standard heart function tests. objectives: - to develop and test new methods for imaging the heart in children with muscular dystrophy. eligibility: - children and adolescents between 8 and 17 years of age who have muscular dystrophy. design: * participants will be screened with a physical exam and medical history. * participants will provide a blood sample at the start of the study. they will also have heart function tests before having the imaging study. * participants will have a cardiac mri scan that will last up to 60 minutes. some tests will require a mri contrast agent (a drug that helps the image appear more clearly on the scan).

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. using the framework of the cooperative international neuromuscular research group (cinrg) and the clinical and translational science award (ctsa) consortium, this pilot study will assess cardiac outcome measures in children obtained by gadolinium enhanced cardiac magnetic resonance imaging (mri) and echocardiographic methods that can be reliably implemented across a consortium of clinical sites devoted to the study of pharmaceutical treatments for muscular dystrophy. these cardiac mri scans will be shared with the pitt1109 research protocol in all subjects that are enrolled in both studies.

Eligibility criteria:
* inclusion criteria: * male or females with a diagnosis of duchenne, becker, or limb girdle muscular dystrophy. * 8 to 100 years of age. exclusion criteria: * day-time users of continuous positive airway pressure (cpap) * sip ventilator users * invasive ventilator dependent * pregnant minors (when uncertain, participants will undergo urine testing) or lactating minors * decompensated congestive heart failure (unable to lie flat during cmr) * impaired renal excretory function (calculated glomerular filtration rate less than 30ml/min) * contra-indications to magnetic resonance imaging: * cardiac pacemaker or implantable defibrillator * cerebral aneurysm clip * neural stimulator * metallic ocular foreign body * harrington-rod * 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

Keywords: mri muscular dystrophy cardiac myocardium intramyocardial fat