Correlation Between Cardiac Output and Cerebral Blood Flow, Brain Atrophy in Normal Aging

一般认为，在正常受试者中，心输出量的变化而没有血压的变化与脑血流的调节无关。然而，我们经常遇到老年患者出现短暂的心律失常或心动过缓，但血压没有下降，精神状况也有所恶化。这一事实表明，心输出量的减少显着参与脑血流量的调节，而不依赖于血压的变化。心输出量与脑血流量、脑功能的相关性研究较少。本研究探讨了正常老年人心输出量与脑功能、形态学改变的相关性。(1)正常老年人局部脑血流量（rCBF）和脑萎缩的关系：25名正常老年人（平均75.4岁）。方法：采用133氚吸入法测定rCBF。采用无创重呼吸法测定心输出量。以QC/BSA为指标， ...更多信息 心输出量采用0.15T磁共振成像仪进行磁共振成像，并在MRI片上计算脑萎缩指数（BAI）。结果：1）平均rCBF与心输出量无相关性（r=0.28）。2)脑血管阻力（CVR）与心输出量呈显著正相关（r=-0.42，p <$0.05）。3)BAI与心输出量无关。(2)正常成人rCBF与心理功能的关系受试者：48名正常成人（平均60岁）。方法：采用日本韦氏老年记忆量表（韦氏记忆量表）的简化版和改良版，以Okabe的智力测验为工具，对被试的言语智力进行评定。采用Ko' Block测验评价操作智力。采用相同的方法测量心输出量和rCBF。结果：（1）心输出量与年龄呈显著正相关（r=-0.319，p <0.05）。2)心输出量与平均rCBF（r=-0.319，p<0.05）和CVR（r=-0.32，p<0.05）显著相关。3)言语智力与心输出量也有显著相关性（r=0.316，p<0.05）。3）MRI室周高信号（PVH）与事件相关电位P300的关系。方法：PVH的MRI分级为0 ~ IV级。采用两种不同的纯音刺激，在Cz上测量奇数球刺激的P300潜伏期。结果：1）年龄与PVH、P300潜伏期之间存在显著相关性。2)心输出量与PVH分级和P300潜伏期无相关性。3)血压与心输出量之间无相关性。结论：正常老年人和成人心输出量与CVR显著相关。提示心输出量是调节CVR的重要因素。此外，在正常成人中，平均rCBF和言语智力与心输出量相关。提示心输出量是调节脑血流量的重要因素之一，并在一定程度上参与了老年人心理功能的衰退。少

It is generally believed that changes in cardiac output without blood pressure changes is indifferent to regulation of cerebral blood flow in normal subjects. However, we often experienced that aged patient who had transient arrythmia or bradycardia showed mental deterioration without decrease in blood pressure. This fact suggests that decrease in cardiac output significantly participates on regulation of cerebral blood flow independent with the changes in blood pressure. There are few reports studied the correlation between cardiac output and cerebral blood flow, brain function. We investigated the correlation between cardiac output and brain function, morphorogical changes in normal aging.(1) Relation to regional Cerebral Blood Flow (rCBF) and brain atrophy in normal aged Subjects : Twenty-five normal elderly people (mean 75.4 years). Methods : The rCBF was measured using 133Xe inhalation method. Cardiac output was measured by non-invasive re-breathing method. We used QC/BSA as index … More of an cardiac output. Magnetic resonance imaging was performed by 0.15T MRI and brain atrophy index (BAI) was calculated on MRI film. Results : 1) The mean rCBF did not correlate to cardiac output (r=0.28). 2) Cerebro-Vascular Resistance (CVR) significantly correlated to cardiac output (r=-0.42,p<0.05). 3) The BAI did not correlate to cardiac output.(2) Relation to rCBF and mental function in normal adults Subjects : Forty-eight normal adults (mean 60 years). Methods : Verbal intelligence was evaluated by Okabe's mental test (shortened and modified version of Wechsler Memory Scale for Japanese aged). Performance intelligence was evaluated by Ko' Block Test. Cardiac output and rCBF were measured by the same methods. Results : 1) The cardiac output significantly correlated to age (r=-0.319, p<0.05). 2) Cardiac output significantly correlated to mean rCBF (r=-0.319, p<0.05) and CVR (r=-0.32, p<0.05). 3) Verbal intelligence also significantly correlated with cardiac output (r=0.316, p<0.05).3) Relation to Peri-Ventricular High intensity (PVH) on MRI and event related potential P300 Subjects : Ninety-two normal adults (mean 56.5 years). Methods : PVH was evaluated by grading from 0 to IV on MRI. P300 latency was measured on Cz by odd ball stimuli using two different pure sounds. Results : 1) There were significant correlations between age and PVH, between age and P300 latency. 2) Cardiac output did not correlate to grade of PVH and P300 latency. 3) There was no correlation between blood pressure and cardiac output. Conclusion : Cardiac output significantly correlated with CVR in normal aged subjects and adults. This result indicates that cardiac output is important factor to regulate CVR. Moreover, mean rCBF and verebal intelligence correlated with cardiac output in normal adults. These results suggests that cardiac output is one of the important factor to regulate CBF and it participates in some extent to deteriorate of mental function in aging. Less