Akutsu Y, Hara T, Watanabe T, Yamanaka H, Okazaki O, Kashida M, Michihata T, Hasegawa M, Harumi K, Katagiri T
Third Department of Internal Medicine, Showa University School of Medicine, Tokyo, Japan.
Jpn Circ J. 1994 May;58(5):303-14. doi: 10.1253/jcj.58.303.
We measured regional myocardial blood flow (RMBF) by positron emission tomography (PET) with 13N-ammonia at rest and during low-grade exercise using a bicycle ergometer fixed at 25 watts for 6.5 min. The ischemic area with severe coronary artery stenosis was evaluated in terms of quantitative RMBF. The study was performed in 46 subjects consisting of 19 patients with old myocardial infarction, 20 with effort angina pectoris, and 7 normal individuals. RMBF was calculated using the radioactivity in myocardial tissue measured by PET and the radioactivity in arterial blood. The PET data were compared with coronary arteriographic findings and ECG findings. When the analysis was restricted to the anterior wall of the myocardium, it was found that exercise caused RMBF to increase by 44.9% (n = 28) in normal area, to increase by 23.3% (n = 37) in severely stenotic area (stenosis > or = 90%), and to decrease by 17.4% (n = 20) in infarcted area. When we considered only the infarcted area of the entire heart, exercise caused RMBF to decrease by 26.6% (n = 30) in the area of angiographically positive collaterals, and to increase by 0.8% (n = 31) in the area of negative collaterals. Thus, we were able to quantitate the degree of ischemia in myocardium that was associated with severe coronary artery stenosis. By application of low-grade exercise, RMBF in normal myocardium increased, while RMBF in myocardium perfused by collaterals decreased.
我们使用13N-氨，通过正电子发射断层扫描（PET）在静息状态和低强度运动期间测量局部心肌血流量（RMBF），低强度运动使用固定为25瓦的自行车测力计进行6.5分钟。根据定量RMBF评估严重冠状动脉狭窄的缺血区域。该研究在46名受试者中进行，包括19名陈旧性心肌梗死患者、20名劳力性心绞痛患者和7名正常个体。使用PET测量的心肌组织中的放射性和动脉血中的放射性来计算RMBF。将PET数据与冠状动脉造影结果和心电图结果进行比较。当分析仅限于心肌前壁时，发现在正常区域运动使RMBF增加44.9%（n = 28），在严重狭窄区域（狭窄≥90%）增加23.3%（n = 37），在梗死区域减少17.4%（n = 20）。当我们仅考虑整个心脏的梗死区域时，运动使血管造影显示有侧支循环的区域的RMBF减少26.6%（n = 30），使无侧支循环区域的RMBF增加0.8%（n = 31）。因此，我们能够定量与严重冠状动脉狭窄相关的心肌缺血程度。通过应用低强度运动，正常心肌中的RMBF增加，而由侧支循环灌注的心肌中的RMBF减少。
