Researchers Hope Study Will Increase Lifespan of Children with Duchenne Muscular Dystrophy

Monday, November 14, 2011

A new study may help prolong the lives of children with Duchenne Muscular Dystrophy.

Cincinnati Children’s Hospital Medical Center researchers have found that a common, non-invasive imaging method called speckle tracking can detect changes in the heart in young children with Duchenne Muscular Dystrophy, or DMD. Further studies are needed to determine whether earlier treatment will slow the onset of heart failure, which is the leading cause of death in these patients.

“The disease process is clearly evident long before we can tell based on standard echocardiographic measures used to detect changes in heart function,” says Thomas Ryan, MD, PhD, a cardiologist at Cincinnati Children’s and lead author of the study. “Speckle tracking, which is a common echocardiographic imaging technique, gives us a way to see changes in function in children too young to receive an MRI without sedation.”

Dr. Ryan will present his study Monday November 14 at the annual meeting of the American Heart Association in Orlando.

Children under 5 years old often do not do well in getting a cardiac MRI, mostly because they have to lie still for a long time and also because the machine is noisy.

Using speckle tracking, physicians can detect circumferential strain, a measure of how the heart contract beyond squeezing as it pumps blood to the body. Dr. Ryan and his colleagues found that young children with DMD have lower strain than patients without DMD and thus lower function.

Not only did speckle tracking identify abnormal function of the heart as whole, but it also identified segments of the heart that are abnormal, including segments known to have abnormalities such as fibrosis, or scarring.

Dr. Ryan examined echocardiograms of 63 children, 8 years old and younger, with DMD. These echocardiograms were taken between 2009 and 2010. Using standard echocardiogram methods, Dr. Ryan could not detect global functional abnormalities using shortening fraction, a traditional measure of how well the heart squeezes. With speckle tracking software, however, he was able to detect and measure abnormalities in the heart as a whole and in specific segments of the heart in DMD boys as young as 5 with DMD.

“Cardiomyopathy, a disease of the heart muscle, is inevitable in patients with DMD,” says Dr. Ryan. “Most kids with DMD live longer than ever before, and stay ambulatory longer, because of better treatment of skeletal muscle and respiratory disease. As such, the leading cause of death is from cardiomyopathy. We’re hoping to add to their lifespan.”

About Cincinnati Children’s

Cincinnati Children’s Hospital Medical Center ranks third in the nation among all Honor Roll hospitals in U.S. News and World Report’s 2011 Best Children’s Hospitals ranking. It is ranked #1 for gastroenterology and in the top 10 for all pediatric specialties – a distinction shared by only two other pediatric hospitals in the United States. Cincinnati Children’s is one of the top two recipients of pediatric research grants from the National Institutes of Health. It is internationally recognized for improving child health and transforming delivery of care through fully integrated, globally recognized research, education and innovation. Additional information can be found at www.cincinnatichildrens.org