 Patients with scleroderma are known to have endothelial dysfunction and limited data suggested an association between the degree of endothelial function in scleroderma and the presence of PAH. However, these data is preliminary and has not been used to predict response to PAH-specific therapy or the development of PAH. We will test patients with cirrhosis because they tend to have PAH in the context of a hyperdynamic instead of a hypodynamic state as observed in scleroderma and PAH. 