Viagra helps children with heart defects PHILADELPHIA, May 9 (UPI) -- Viagra, or sildenafil may give a boost to underdeveloped hearts in children and young adults with congenital heart defects, U.S. researchers say. Study leader Dr. David J. Goldberg, a pediatric cardiologist at The Children's Hospital of Philadelphia, and colleagues randomly assigned 27 children and young adults to receive either sildenafil or a placebo for six weeks. After a six-week break in treatment, the subjects were switched to the opposite treatment course. The study team used echocardiograms to measure myocardial performance index, an indicator of the heart's overall ability to pump blood, Goldberg said. Because sildenafil has also shown promise as a treatment for adults with heart failure, the Children's Hospital researchers are exploring whether it may benefit younger patients with certain types of congenital heart disease. The study, published online in the journal Pediatric Cardiology, found sildenafil significantly improved echocardiographic measures of heart function in children and young adult survivors of single ventricle heart disease palliation. The patients in the double-blind, short-term study had a mean age of 14.9 years and had undergone a Fontan operation in early childhood. The Fontan surgery redirects blood circulation in patients born with a severely underdeveloped ventricle, one of the heart's two pumping chambers.