Use of ambrisentan for preventing or alleviating cardiac function injury caused by hypoxia

A use of ambrisentan or pharmaceutically acceptable salts thereof for preparing medicines for preventing or alleviating cardiac function injury or secondary diseases thereof caused by hypoxia, said secondary diseases being selected from right ventricular hypertrophy, pulmonary hypertension, vascular proliferation, pulmonary artery blood vessel thickening, pulmonary oedema and respiratory failure.