4. Serious cardiovascular disease: Ⅱ-level myocardial ischemia or myocardial infarction, arrhythmia (including QT interval prolongation, for man ≥ 450 ms, for woman ≥ 470 ms); III ~ IV level cardiac function insufficiency, or echocardiography showed that left ventricular ejection fraction (LVEF < 50%);