Abstract: AIM To investigate the short-term efficacy and safety of fasudil( a Rho kinase inhibitor)monotherapy in patients with severe pulmonary arterial hypertension( PAH) secondary to congenital heart disease( CHD). METHODS Enrolled in the study were 21 patients with severe PAH secondary to CHD from January 2011 to August 2012 in our Department. All patients were given basic drug treatment for PAH and then continuously given fasudil 60 mg i. v. twice a day for 14 days. After fasudil treatment,changes were observed in the 6-min walking distance according to all relevant hemodynamic parameters( including pulmonary arterial pressure,left to right and right to left shunt volume,pulmonary vascular resistance,systemic and pulmonary blood flow,systemic pressure,systemic vascular resistance,and cardiac output and femoral arterial blood oxygen saturation),anatomy parameters( including each chamber size and left ventricular ejection fraction) and plasma brain natriuretic peptide and liver and kidney functions after medication. RESULTS After continuous administration of fasudil for 14 days,the 6-min walking distance increased dramatically from( 445 ± 490) m to( 471 ± 40) m,with significant statistical difference. WHO cardiac functions improved significantly( P < 0. 05). Compared with baseline,plasma NT-pro BNP significantly decreased from( 788 ± 622. 61) pg / ml to( 464 ± 392. 80) pg / ml( P =0. 043),with significant statistical difference. Compared with baseline, mean right atrial pressure decreased from( 6. 12 ± 2. 26) mm Hg to( 5. 2 ± 1. 84) mm Hg( P < 0. 05) and right to left shunt volume significantly reduced from( 22. 9 ± 16. 21) % to( 18. 3 ± 15. 98) %( P < 0. 05). No significant difference was observed in mean pulmonary artery pressure,pulmonary vascular resistance,systemic and pulmonary blood flow ratio,systemic and pulmonary vascular resistance ratio,femoral arterial oxygen saturation and cardiac indexes,but all improved to some extent. No statistical differences were found in systemic arterial pressure and systemic vascular resistance and no obvious changes were seen in liver and kidney functions. CONCLUSION Short-term treatment of fasudil is safe and well tolerated and can effectively improve exercise capacity and hemodynamic parameters in patients with severe pulmonary arterial hypertension secondary to CHD.