Malatino L S, Bellofiore S, Costa M P, Lo Manto G, Finocchiaro F, Di Maria G U
Istituto di Clinica Medica, University of Catania, Italy.
Stroke. 1992 Dec;23(12):1728-32. doi: 10.1161/01.str.23.12.1728.
The aim of our study was to evaluate by transcranial Doppler ultrasonography the dynamics of blood flow velocity changes in the middle cerebral artery during and after hypocapnia-induced vasoconstriction in untreated essential hypertensive patients.
Sixteen hypertensive patients (10 men and six women, 29-62 years of age) and 10 healthy control subjects (six men and four women, 30-62 years of age) were studied. Patients with mild-to-moderate essential hypertension (mean +/- SE blood pressure, 171/106 +/- 3/2 mm Hg) belonged to stage I or II of the World Health Organization classification. Mean blood flow velocity in the middle cerebral artery, arterial blood pressure, and end-tidal CO2 partial pressure were recorded at baseline, during 2-minute hyperventilation, and every 30 seconds up to 5 minutes after hyperventilation.
End-tidal CO2 partial pressure values overlapped in the two groups throughout the study. Baseline values of mean blood flow velocity in hypertensive patients were similar to those in normotensive subjects (mean +/- SE values, 64.7 +/- 3.9 cm/sec versus 58.6 +/- 3.7 cm/sec). A similar fall in mean blood flow velocity was observed in hypertensive patients and normotensive subjects (43.2 +/- 2.8% versus 46.7 +/- 3.6%). Mean blood flow velocity reverted to baseline more quickly in hypertensive patients: 1.5 minutes after hyperventilation, mean blood flow velocity was 60.7 +/- 3.1% and 84.9 +/- 1.8% of control in normotensive subjects and hypertensive patients, respectively. No changes in arterial blood pressure were observed in either group throughout the study.
This study demonstrates that the recovery of blood flow velocity in the middle cerebral artery after hyperventilation is faster in hypertensive patients than in normal subjects, thus providing further evidence that chronic hypertension is associated with changes in the dynamics of cerebral blood vessel reactivity.
我们研究的目的是通过经颅多普勒超声评估未经治疗的原发性高血压患者低碳酸血症诱导的血管收缩期间及之后大脑中动脉血流速度变化的动态情况。
对16例高血压患者（10例男性，6例女性，年龄29 - 62岁）和10例健康对照者（6例男性，4例女性，年龄30 - 62岁）进行研究。轻度至中度原发性高血压患者（平均±标准误血压为171/106±3/2 mmHg）属于世界卫生组织分类的I期或II期。在基线、2分钟过度通气期间以及过度通气后直至5分钟每30秒记录大脑中动脉的平均血流速度、动脉血压和呼气末二氧化碳分压。
在整个研究过程中，两组的呼气末二氧化碳分压值有重叠。高血压患者大脑中动脉平均血流速度的基线值与血压正常者相似（平均±标准误值，分别为64.7±3.9 cm/秒和58.6±3.7 cm/秒）。高血压患者和血压正常者的平均血流速度出现了相似的下降（分别为43.2±2.8%和46.7±3.6%）。高血压患者的平均血流速度恢复到基线的速度更快：过度通气后1.5分钟，血压正常者和高血压患者的平均血流速度分别为对照值的60.7±3.1%和84.9±1.8%。在整个研究过程中，两组的动脉血压均未观察到变化。
本研究表明，高血压患者过度通气后大脑中动脉血流速度的恢复比正常受试者更快，从而进一步证明慢性高血压与脑血管反应性动力学变化有关。
