Spence J D
Can J Neurol Sci. 1977 May;4(2):93-7.
The treatment of high blood pressure prevents death from congestive heart failure, hypertensive nephropathy, and encephalopathy, and strokes from cerebral arteriolar disease (lacunes, hemorrhage from microaneurysms). However, atherosclerosis, manifested as coronary artery disease is just as frequent a cause of death in well-controlled hypertensives as in poorly-controlled patients. Increasing evidence suggests that increased blood velocity, by causing turbulence and high shear rates at the endothelial surface of arteries, may be important in the pathogenesis of atherosclerosis. Turbulence has been observed in cerebral berry aneurysms. In order to measure the effects of antihypertensive agents on blood velocity, a new method of analysing Doppler ultrasound velocity recordings has been developed. Studies in Rhesus monkeys show the following: In doses which reduce diastolic pressure by 13-28%, propranolol decreased mean blood velocity (MV) by 17%, clonidine decreased MV by 14%, while methyldopa increased MV 12%, and hydralazine increased MV by 52%. (p less than .00001). It is hypothesized that enlargement of berry aneurysms, the progression of cerebral atherosclerosis, and embolism from carotid lesions might all be decreased by the selection of antihypertensive agents which decrease blood velocity.
高血压的治疗可预防因充血性心力衰竭、高血压性肾病、脑病以及脑小动脉疾病（腔隙性梗死、微动脉瘤出血）导致的中风而死亡。然而，表现为冠状动脉疾病的动脉粥样硬化在血压控制良好的高血压患者和控制不佳的患者中一样，都是常见的死亡原因。越来越多的证据表明，动脉内皮表面因血流速度增加而产生的湍流和高剪切力可能在动脉粥样硬化的发病机制中起重要作用。在脑浆果状动脉瘤中已观察到湍流。为了测量抗高血压药物对血流速度的影响，已开发出一种分析多普勒超声速度记录的新方法。对恒河猴的研究表明：在使舒张压降低13% - 28%的剂量下，普萘洛尔使平均血流速度（MV）降低17%，可乐定使MV降低14%，而甲基多巴使MV增加12%，肼屈嗪使MV增加52%。（p小于0.00001）。据推测，选择降低血流速度的抗高血压药物可能会减少浆果状动脉瘤的扩大、脑动脉粥样硬化的进展以及颈动脉病变引起的栓塞。
