QT离散度在急性心肌梗塞早期的演变和影响因素

目的：探讨急性心肌梗塞（ＡＭＩ）患者体表心电图ＱＴ离散度的演变规律及影响因素。方法：使用５０ｍｍ／ｓ纸速１２导同步心电图机对３７例患者发病１周内４次（入院即刻、发病２、４、７ｄ）ＱＴ离散度及相关指标进行动态观察，并与５０例正常对照进行对比分析。结果：ＡＭＩ早期ＱＴ离散度等指标较正常对照明显增大，且存在动态演变：入院２ｄ达最大值，４ｄ减小，７ｄ更小但仍高于正常。梗塞相关冠脉再通可明显减小ＱＴ离散度等指标：这种作用在下壁ＡＭＩ患者表现为抑制ＱＴ离散度等指标在发病２ｄ的增加；在前壁ＡＭＩ则表现为加快ＱＴ离散度等指标在４ｄ后的恢复。ＡＭＩ部位本身对ＱＴ离散度等指标的演变也有影响。与下后壁ＡＭＩ相比，前壁ＡＭＩ者的ＱＴ离散度增大较明显，恢复较慢。结论：ＡＭＩ急性期ＱＴ离散度等指标存在动态演变，梗塞相关冠脉再通可以改善ＱＴ离散度。

DYNAMIC CHANGE OF QT DISPERSION IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION

Objective:To evaluate the dynamic change of QT dispersion at the early stage of acute myocardial infarction(AMI) and its response to thrombolytic therapy.Methods:Synchrony 12 lead electrocardiogram was recorded with 50 mm/s paper speed in 37 patients with AMI at admittion,in the second day,in the forth day and in the seventh day after the occurrence of AMI and in 50 healthy controls.QT dispersion(QTd),heart rate corrected QT dispersion(QTcd) and QT adjusted dispersion(QTad) were used for analysis.Results:Patients with AMI had significant larger QTd,QTcd and QTad than the controls.All the QTd parameters had the same pattern of dynamic change rising to maximum in the second day after AMI,and falling after the forth day.Patients with successful reperfusion had significant smaller QTd,QTcd and QTad than those without reperfusion.In patients with anterior AMI,successful reperfusion promoted the falling of QTd after the forth day of AMI,whereas in those with inferior AMI,successful reperfusion seemed to prevent the rising of QTd in the second day.Patients with inferior AMI or with left circumflex or right coronary artery occlusion had smaller QTd in the forth and the seventh day after AMI than those with anterior AMI or left anterior descending coronary artery occlusion.Conclusion:QTd with other two parameters have dynamic change in the early stage of AMI.Successful reperfusion is associated with little change of QTd in AMI patients.