A six-week course of sildenafil 200 mg three times daily significantly improved echocardiographic measures of ventricular performance in a study of 27 youths (mean age 14.9 years) with single-ventricle defects.

A mean 11.3 years after Fontan surgery to redirect blood circulation, sildenafil treatment significantly improved myocardial performance index and other cardiac measures compared with six weeks of placebo, according to a report in Pediatric Cardiology 2012;33:689-696.