心肌缺血阈值及其变异度动态心电图检测研究

DCG Studies on Ischemic Threshold and Its Variabilityin Patients With Coronary Artery Disease

本文对５２例冠心病（ＣＡＤ）患者进行２４小时动态心电图检测。共检出４７４阵缺血发作，以慢频率缺血（７７．６％）居多。夜间心肌缺血阈值较低，且缺血持续时间及ＳＴ段压低程度明显长和重于昼间。受检者心肌缺血阈值的变异度（Ｖ）为２２．６±１。７％，与缺血总阵数呈密切正相关。单纯快、慢频率缺血者与混合型缺血者比较，后组总缺血阵数，总缺血时间、Ｖ均较前组为劣。本研究提示。日常生活中的缺血发作多为血管张力变化引起的心肌供氧减少所致；ＣＡＤ患者间冠脉张力存在较大的个体差异，冠脉张力的高低同心肌缺血程度有一定的联系。此外．推测混合型缺血患者的冠际病变较重；应予足够重视。

patients with coronary artery disease were investigated by 24-hour ambu-latory electrocardiography. The results indicated that the slow heart rate dependent ischemiaswere predominent (77. 6%) among the total 474 ischemic episodes during daily activities andthat nocturnal ischemias had lower threshold and longer mean ischemic time as well as deeper STdepression. The variability of ischemic threshold (V) varied from 2% to 59% ,which correlatedpositively with total number of ischemic episedes (r= 0. 5155). In addition , we found that 32patients with mixed type of ischemia were worse than 20 patients with pure type of ischemia onrespects of total number and toatal period of ischemic episodes and V value. This study suggestedan essential role of enhanced vasomotor tone in induction of myocardial ischemia during daily lifeand confirmed great difference between patients in coronary vasotone. The mixed type ofischemia may be much serious on the extent of coronary artery disease.