Uren N G, Camici P G, Melin J A, Bol A, de Bruyne B, Radvan J, Olivotto I, Rosen S D, Impallomeni M, Wijns W
MRC Cyclotron Unit, Hammersmith Hospital, London, United Kingdom.
J Nucl Med. 1995 Nov;36(11):2032-6.
Myocardial perfusion reserve (hyperemic divided by basal myocardial blood flow) describes vasodilator responsiveness of coronary-resistive vessels. The effect of aging and gender on myocardial perfusion reserve remains controversial.
We studied 56 normal volunteers (21 women, 35 men; aged 50 +/- 20 yr, range 21-86 yr) with 15O-water PET to measure myocardial blood flow during basal and hyperemic states with intravenous dipyridamole (0.56 mg/kg, n = 46) or adenosine (140 micrograms/kg/min, n = 10). For comparative analysis, patients were grouped according to age: < 30 yr (n = 11), 30-49 yr (n = 18), 50-69 yr (n = 15) and > or = 70 yr (n = 12).
Overall, basal flow was 1.00 +/- 0.26 ml/min/g and hyperemic flow was 3.31 +/- 1.38 ml/min/g, resulting in a myocardial perfusion reserve of 3.38 +/- 1.35. There was an increase in basal flow with age (r = 0.45, p < 0.025), although hyperemic flow was only lower in patients > or = 70 yr, causing a significant reduction in myocardial perfusion reserve: 3.54 +/- 0.96 in < 30 yr, 4.23 +/- 1.35 in 30-49 yr, 3.51 +/- 1.21 in 50-69 yr and 1.94 +/- 0.46 in > or = 70 yr (p < 0.05 versus all groups < 70 yr).
Myocardial blood flow during basal and hyperemia conditions are roughly comparable up to 60 yr of age. Above this age, there is significant increase in basal flow associated with an increase in systolic blood pressure. Above 70 yr, there is a significant reduction in hyperemic flow, and thus myocardial perfusion reserve independent of hemodynamic response to vasodilator stress.
心肌灌注储备（充血期心肌血流量除以基础期心肌血流量）描述了冠状动脉阻力血管的血管扩张反应性。衰老和性别对心肌灌注储备的影响仍存在争议。
我们对56名正常志愿者（21名女性，35名男性；年龄50±20岁，范围21 - 86岁）进行了研究，采用15O - 水PET测量基础期和充血期的心肌血流量，静脉注射双嘧达莫（0.56 mg/kg，n = 46）或腺苷（140μg/kg/min，n = 10）。为进行比较分析，患者按年龄分组：<30岁（n = 11），30 - 49岁（n = 18），50 - 69岁（n = 15）和≥70岁（n = 12）。
总体而言，基础期血流量为1.00±0.26 ml/min/g，充血期血流量为3.31±1.38 ml/min/g，心肌灌注储备为3.38±1.35。基础期血流量随年龄增加（r = 0.45，p < 0.025），尽管仅≥70岁患者的充血期血流量较低，导致心肌灌注储备显著降低：<30岁组为3.54±0.96，30 - 49岁组为4.23±1.35，50 - 69岁组为3.51±1.21，≥70岁组为1.94±0.46（与所有<70岁组相比，p < 0.05）。
60岁之前，基础期和充血期的心肌血流量大致相当。超过这个年龄，基础期血流量显著增加，同时收缩压升高。70岁以上，充血期血流量显著降低，因此心肌灌注储备与血管扩张剂应激的血流动力学反应无关。
