Abstract: Plasma endothelin (ET) with radioimmunoassay was messured respectively in AMI group (23 patients) angina pectoris group (26 patients) and coronary heart disease heart failure group(9 patients).ET in three groups was much higher than in control group.ET became normal one week after attack in AMI group.ET was highest in angina group at angina onset and returned to normal in one week as the symptoms relieved.ET was relevant to the degree of heart failure(HF).It was higher in Ⅳ grade HF than in Ⅲ grade HF and reduced with remission at a slower rate.ET was obvious higher in AMI group than in angina group.We consider that ET is correlated with myocardial ischemia , anoxia and cardiac function status.So ET can be used as the parameter of judging cardiac function status and assistant parameter of differiential diagnosis between AMI and angina.ET also can be used in dynamic observating on patients of post AMI and assesting the therapeutic effect and prognosis.

Key words: endothelin, angina, AMI, heart failure