目的　研究不同水平 +Gz 暴露及高G训练对人体心脏功能的后效应。　方法　 2 4名歼击机飞行员接受基础 +Gz 耐力测查 (最高暴露于 +4 2 5～ 4 5Gz)、+7 0Gz 或 +8 0Gz 高G训练 ,观察 +Gz 暴露后 2h心电图、心脏彩超和次日心肌酶 (AST、LDH、CK)的变化。　结果　接受基础 +Gz 耐力测查和 +7 0Gz 高G训练后 2h的心电图无明显变化。心脏彩超检查示 :基础 +Gz 耐力测查后 2h ,升主动脉和肺动脉主干内径、左心房和右心房内径、右心室内径、左心室舒张末内径、左心室短轴缩短率均减小 (P <0 0 5或P <0 0 1 ) ;采取抗荷措施进行 +7 0Gz 高G训练后 2h ,这种变化无明显加重或有减轻趋势。左心室舒张末内径差值、收缩末内径差值和射血分数 +Gz 暴露后无明显变化。接受 +8 0Gz高G训练后次日 ,血液中心肌酶无明显升高。　结论　较高水平的 +Gz 暴露可在短时间内对心脏收缩和舒张功能造成轻度不利影响 ,但左心室泵血功能和心电图无明显变化。在高G训练中采取抗荷措施对心脏功能具有保护作用 Objective To investigate the post-effects of different levels of + Gz exposure and high G training on human heart function. Method 2 Four fighter pilots received basic Gz endurance test (up to +425 ~ 45Gz), +70 Gz or +80 GZ high G training, and observed 2h electrocardiogram, Changes of myocardial enzymes (AST, LDH, CK). Results There was no significant change in the electrocardiogram at 2h after basal + Gz endurance test and +7 0Gz high G training. Color Doppler echocardiography showed that at 2h after basal + Gz endurance test, the diameter of the ascending aorta and pulmonary artery, the diameter of the left atrium and the right atrium, the diameter of the right ventricle, the diameter of the left ventricle, and the shortening of the left ventricle were all decreased <0 0 5 or P <0 0 1). After 2 hours of +7 0Gz high G training with anti-stress measures, there was no obvious increase or a tendency to decrease. Left ventricular end-diastolic diameter difference, end-systolic diameter difference and ejection fraction + Gz no significant change after exposure. After receiving the training of +8 0Gz high G the next day, there was no obvious increase of myocardial enzymes in the blood. Conclusions Higher levels of + Gz exposure may have mild adverse effects on systolic and diastolic function in a short period of time, but there is no significant change in left ventricular pumping function and ECG. In high G training to take anti-Dutch measures of cardiac function has a protective effect