ASSESSMENT OF CEREBROVASCULAR REACTIVITY WITH LOW-DOSES OF NITROGLYCERIN - TRANSCRANIAL DOPPLER AND CEREBRAL BLOOD-FLOW

Twenty-five men without signs of cerebrovascular diseases were examined by transcranial Doppler and cerebral blood flow (CBF) studies before and after sublingual administration of a low dose of nitroglycerin (0.25 mg). Several parameters of blood flow in the middle cerebral artery (MCA) were measured from both sides. CBF studies were performed by means of the Xe-133 inhalation method using a multidetector system. There were no significant changes of CBF after nitroglycerin. Statistically significant changes of blood flow in MCA were recorded only for linear peak systolic velocity and time-averaged mean velocity. We concluded that even a low dose of nitroglycerin may result in marked MCA dilation in healthy subjects, but it is not sufficient to change CBF.