7Chai PJ,Williamson JA,Lodge AJ,et al.Effects of ischemia on pulmonary dysfunction after cardiopulmonary bypass[J].Ann Thorac Surg,1999,67(3):731-735.
8Michelakis E,Tymchak W,Lien D,et al.Oral sildenafil is an effective and specific pulmonary vasodilator in patients with pulmonary arterial hypertension:comparison with inhaled nitric oxide[J].Circulation,2002,105(20):2398-2403.
9Wilkens H,Guth A,Konig J,et al.Effects of inhaled iloprost plus oral sildenafil in patients with primary pulmonary hypertension[J].Circulation,2001,104 (11):1218-1222.
