Response to a single dose of sildenafil in single-ventricle patients: an echocardiographic evaluation.

New evidence of increased phosphodiesterase-5 (PDE-5) in hypertrophied human myocardium suggests that sildenafil, a selective PDE-5 inhibitor, may improve muscle contraction and therefore improve ventricular function. The purpose of this study was to compare ventricular function as assessed by echocardiography in 10 surgically palliated single-ventricle patients at baseline and again after a single dose of sildenafil. The velocity time integral of the ventricular outflow tract was increased 2 h after sildenafil administration (p = 0.01), thus suggesting an improvement in cardiac output.