 - Pulmonary vascular resistance PVR 1.5 wood units, and 2. Age 18 to 75 years 3. Right ventricular failure defined by right atrial pressure 7 mmHg along with either dilated right ventricle, or absence of inferior vena cava collapse or BNP 100 pgml 4. Patients of childbearing age must be practicing effective birth control. 5. Normal left ventricular function as assessed by echocardiogram, multiple gated acquisition MUGA cardiac scan, or invasive left ventriculography. 