Transcranial Doppler sonography and ambulatory blood pressure monitoring in patients with hypertension

To appraise the value of transcranial Doppler sonography (TCD) for assessme nt of hypertensive cerebrovascular damage, the relationship between ambulat ory blood pressure (BP) and indices of cerebral circulation determined by T CD was investigated. Subjects were 55 inpatients with or without hypertensi on, including 13 patients with histories of cerebrovascular attacks. Mean f low velocity (MFV) in the middle cerebral artery was measured by TCD, then the cerebrovascular resistance index (CVRI; mean BP/MFV) and the Fourier PI 1 (pulsatility index of the first Fourier harmonic of the flow-velocity wav eform) were determined as indices of cerebrovascular resistance. CO2 reacti vity of MFV was estimated as an index of cerebrovascular flow reserve. CVRI positively correlated with both daytime and nighttime BP as well as with a ge (p<0.01). Fourier PI1 positively correlated with nighttime BP and age (p <0.01). CO2 reactivity did not correlate with any of the ambulatory BP para meters, but negatively correlated with age (p<0.01). LV mass index signific antly correlated with ambulatory BP parameters, CVRI, and Fourier PI1, but did not correlate with CO2 reactivity. Multiple regression analyses showed that nighttime systolic BP was a significant correlate for CVRI and Fourier PI1, but not for CO2 reactivity, and that history of cerebrovascular attac k was significant for CVRI and CO2 reactivity. We conclude that cerebrovasc ular resistance determined by TCD accords with the results of ambulatory BP and LVMI, and thus could be successfully used to detect the early stage of hypertensive cerebrovascular change. Cerebrovascular flow reserve would be relatively preserved in hypertensive patients without cerebrovascular dise ases.