Preliminary work suggests that Magnetic Resonance Imaging (MRI) determined right to left ventricular volume ratio's of greater than 2:1 with associated tricuspid regurgitation, right ventricular regurgitant volumes of greater than 50%, and right ventricular ejection fractions less than 45% are common among patients with severe right ventricular failure and dysfunction. These patients are in need of pulmonary valve replacement and have routinely been referred for surgical intervention.