Lu D
First Affiliated Hospital, Zhejiang Medical University, Hangzhou.
Zhonghua Xin Xue Guan Bing Za Zhi. 1992 Dec;20(6):357-8, 389.
The myocardial ischemic threshold (heart rate at the onset of ischemia) was assessed in 92 patients with coronary heart disease. The highest myocardial ischemic threshold (HMIT) ranged from 83 to 163 (122 +/- 18) beats/min usually happened during activities at the daytime. The lowest myocardial ischemic threshold (LMIT) ranged from 45 to 115 (82 +/- 17) beats/min usually happened when awaken early morning or asleep at night. The differences were statistically significant (P < 0.01). The mean variability of myocardial ischemic threshold (VMIT) was 30.22% (range from 8.2 to 51.2%). The variability was correlated positively with the number of ischemic episodes, negatively with LMIT, and larger in senior-aged group than in middle-aged group (P < 0.001). The authors suggest that LMIT and VMIT may be related to the severity of coronary lesions, coronary tonus, and the patients' prognosis, etc.
对92例冠心病患者进行了心肌缺血阈值（缺血发作时的心率）评估。最高心肌缺血阈值（HMIT）为83至163（122±18）次/分钟，通常发生在白天活动期间。最低心肌缺血阈值（LMIT）为45至115（82±17）次/分钟，通常发生在清晨醒来或夜间睡眠时。差异具有统计学意义（P<0.01）。心肌缺血阈值的平均变异性（VMIT）为30.22%（范围为8.2%至51.2%）。该变异性与缺血发作次数呈正相关，与LMIT呈负相关，且老年组大于中年组（P<0.001）。作者认为，LMIT和VMIT可能与冠状动脉病变的严重程度、冠状动脉张力以及患者的预后等有关。
