Efficacy and safety of sildenafil in the treatment of high altitude heart disease associated with severe pulmonary arterial hypertension in children：a preliminary evaluation
XIA Yan-Liang, YAN Wei-Xiao, CHEN Hong
CJCP . 2014, (7): 745 -748 .  DOI: 10.7499/j.issn.1008-8830.2014.07.018