Lin W, Xiong L, Han J, Leung T, Leung H, Chen X, Wong K S L
Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong SAR, China.
Eur J Neurol. 2014 Feb;21(2):326-31. doi: 10.1111/ene.12314. Epub 2013 Dec 7.
External counterpulsation (ECP) is a novel method to increase cerebral blood flow, which may benefit acute ischaemic stroke patients. Our aim was to identify whether the hemodynamic effect of ECP is associated with cerebral vasoreactivity to breath-holding.
Thirty-seven recent ischaemic stroke patients with large artery steno-occlusive disease were recruited together with 20 healthy controls. All underwent ECP treatment and a breath-holding test combined with transcranial Doppler monitoring on bilateral middle cerebral arteries was performed. The data of the stroke patients were designated as ipsilateral or contralateral based on the side of the infarct, whilst the average of both sides was used in controls. The cerebral augmentation index (CAI) was used to evaluate the augmentation effects of ECP. Cerebral vasoreactivity was assessed by using the breath-holding index (BHI).
Middle cerebral artery mean flow velocities significantly increased in the stroke group after ECP but not in controls. BHIs were much smaller in the stroke group than in the controls. The CAI did not correlate with the BHI in either the ipsilateral or contralateral side of the stroke group or in controls. For stroke patients, BHI was significantly lower on the ipsilateral side than the contralateral side, but the CAI showed no difference between the two cerebral hemisphere sides. The CAI of stroke patients was significantly related to mean blood pressure change on the ipsilateral side.
The dynamic augmentation effects of ECP as measured by the CAI were different from the well established vasoreactivity to breath-holding. The CAI is suggested as a measure of how well the brain accommodates blood flow augmentation during ECP.
体外反搏（ECP）是一种增加脑血流量的新方法，可能对急性缺血性脑卒中患者有益。我们的目的是确定ECP的血流动力学效应是否与屏气时的脑血管反应性相关。
招募了37例近期患有大动脉狭窄闭塞性疾病的缺血性脑卒中患者以及20名健康对照者。所有人均接受了ECP治疗，并进行了屏气试验，同时通过经颅多普勒对双侧大脑中动脉进行监测。根据梗死侧将脑卒中患者的数据指定为同侧或对侧，而对照者使用两侧的平均值。使用脑增强指数（CAI）评估ECP的增强效果。通过屏气指数（BHI）评估脑血管反应性。
ECP治疗后，脑卒中组大脑中动脉平均血流速度显著增加，而对照组未增加。脑卒中组的BHI远低于对照组。在脑卒中组的同侧或对侧以及对照组中，CAI与BHI均无相关性。对于脑卒中患者，同侧的BHI显著低于对侧，但CAI在两个脑半球侧之间无差异。脑卒中患者的CAI与同侧平均血压变化显著相关。
通过CAI测量的ECP动态增强效果与已确立的屏气血管反应性不同。建议将CAI作为评估大脑在ECP期间对血流增加适应程度的指标。
