Washington, Nov 19 A drug used to treat erectile dysfunction has been found to improve heart function in children and young adults, say researchers.

Single-ventricle defects are a collection of cardiac malformations that impair the heart's ability to pump blood. Examples include tricuspid atresia, pulmonary atresia/intact ventricular septum and hypoplastic left heart syndrome.

The new study led by The Children's Hospital of Philadelphia revealed that patients with single-ventricle congenital heart disease reported improvement when treated with drug sildenafil.

The Fontan operation is a procedure that redirects systemic venous blood directly to the pulmonary arteries, bypassing the heart. It is the third surgery in a staged palliation for single-ventricle heart defects.

The researchers hypothesized that sildenafil may help cardiac performance by directly improving the squeeze of the heart muscle and by allowing for better filling of the heart.

During the study, researchers randomized 28 children and young adults who had undergone the Fontan operation to receive placebo or sildenafil three times a day for 6 weeks. After a 6-week break, subjects were switched to the opposite treatment course.

They found significant improvement in heart performance during treatment with sildenafil.

"The enhanced heart performance may improve exercise performance and quality of life in these children and young adults," said David J. Goldberg, M.D., pediatric cardiologist at The Children's Hospital of Philadelphia,

The study was presented at the American Heart Association Scientific Sessions in Orlando, Fla. (ANI)