例一男,46岁。发作性心前区闷疼一天,持续性心前区疼痛8小时入院。心率84次,血压120/80。大汗,面色苍白。心界不大,可闻及偶发早搏和第四心音,无杂音,心电图示广泛前壁和下壁心肌梗塞,偶发室性早搏。入院后立即输氧,杜冷丁100mg 肌注,硝酸甘油片和消心痛含化,静滴激化液,利多卡因50mg 静注,利多卡因1～2mg/分静滴,第二日室性早搏消失,3天后停用利多卡因,口服慢心律100mg,一日三次,第10天,突然抽搐,血压、脉搏不能测知,心电示波为室性心动过速,静注利多卡因100mg 无效 10分钟后,再静注利多卡因100mg,25%硫酸镁10ml,5分钟后转为窦性心律.第16日又出现频发室性早搏,静注25%硫酸镁10ml,20分钟后室性早搏消失,其后停用 A male, 46 years old. Preoccupied anterior miserable one day, persistent pain in pre-anterior 8 hours admission. Heart rate 84 times, blood pressure 120/80. Sweating, pale. Heart is small, can be heard and premature premature beats and the fourth heart sound, no noise, ECG wide anterior and inferior wall myocardial infarction, occasional ventricular premature beats. Oxygen delivery immediately after admission, pethidine 100mg intramuscularly, nitroglycerin tablets and anti-heart acidification, intravenous infusion of stimulant, lidocaine 50mg intravenous injection, lidocaine 1 ~ 2mg / min intravenous infusion, the second day of ventricular premature beats disappear , 3 days after the deactivation of lidocaine, oral slow heart rate 100mg, three times a day, the first 10 days of sudden convulsions, blood pressure, pulse can not be measured, ECG wave of ventricular tachycardia, intravenous lidocaine 100mg invalid 10 minutes later, intravenous injection of lidocaine 100mg, 25% magnesium sulfate 10ml, 5 minutes later converted to sinus rhythm. On the 16th and frequent premature ventricular contractions, intravenous injection of 25% magnesium sulfate 10ml, 20 minutes after the room Premature beats disappeared, then disabled