急性心肌梗塞早期和持续的心电图ST段对应改变的意义及与心功能的关系

Early and persistent reciprocal depression of ST segment in acute myocardial infarction:Its significance and relationship with cardiac function

分析104例急性心肌梗塞患者胸痛发作24h内心电图ST段对应性变化及与心功能的关系。发现:44/66例单一部位、8/29例复合部位梗塞和1/9例梗塞原位扩展者心电图有对应ST段改变;有或无对应改变者之间心功能无显著差异,而单一和复合梗塞者之间心功能变化有显著差异;33/51例无对应ST段改变者可找出使ST向量无变化的原因;26例急性下壁梗塞其前壁ST段压低可延伸至V(5～6)导联且发病72h后仍不回复至基线;单纯下壁梗塞者V_(1～4)ST段下降总和与下壁加正后壁者V_(1～4)ST段下降总和之间有显著差异。作者认为:急性心肌梗塞时ST段对应改变系心电向量力变化所致。唯一影响心功能因素是梗塞面积。动态监测ST段对应改变的过程对估计病情和判断预后均极有意义。

104 acute myocardial infarction(AMI)patients′ECGs(within 24 hours after the onset of chest painwere studied to elucidate the machenism of reciprocalST segment depression during the acute phase ofmyocardial infarcfin(MI)and its relationship withcardiac function.The results were as follows:(1)44/66(66.67%)mono-focal MI,8/29(27.59%)multi-focal MI,and 1/9(11.1%)MI expansion hadreciprocal ST segment depression.(2)There was no sig-nificant cardiac function difference between reciprocalgroup and non-reciprocal group,but there wascardiac function difference between mono-focal MIand multi-focal MI.(3)Causes affecting ST vectorchanges could be found in the patients(33/51)withnon-reciprocal ST segment depression.(4)In 26 inferi-or MI patients,ST depression of the anterior leads wasextended to V_(5-6)and did not return to the baseline inthe convalescent phase.(5)The sum of ST segment de-pression in simple inferior MI was less than that of in-ferior and posterior MI.We conclude that:(1)Recipro-al ST segment depssion during AMI is a vector change.The reasons we can not find this change are the delayed ECG recording,low QRS voltage,small sizeof MI,neutralization of MI vectors,and so on.(2)Theonly factor which affects the cardiac function is infarctsize,not ST depression.(3)To some extent,monitoringthe evolution of ST depression is very useful for the as-sessment of MI severity and prognosis.