Is blood flow in the middle cerebral artery determined by systemic arterial stiffness?
OBJECTIVE
The relationship between systemic arterial stiffness and parameters of cerebral circulation is poorly understood. We aimed to assess the relation between pulsatility (PI) and resistance (RI) indexes of the middle cerebral artery (MCA) and aortic pulse wave velocity (PWV) and brachial pulse pressure (PP).


METHODS
Bilateral transcranial Doppler ultrasound (TCD) examination of the MCAs was performed using the GE Vivid 3 Ultrasound, equipped with a 2.5-MHz probe and PI and RI were calculated. Aortic PWV was obtained with the Complior device (Colson France). Conventional blood pressures were measured at the time of TCD. Data regarding risk-profile constituents, habits and medication use were recorded. Subjects with occlusion or significant stenosis of carotid arteries or MCA, previous or acute stroke, temporary ischaemic attack, bilaterally absent transtemporal sonographic windows, dysrhythmia, haematocrit value <30% or >48% were excluded.


RESULTS
Of the 165 included subjects (mean age, 56.70+/-11.80 years, range 22-86 years), 50.3% were men, 20.9% smokers, 20.7% diabetic and 63.4% hypertensive. PWV correlated to both PI (r=0.45, p<0.001) and RI (r=0.36, p<0.001) of MCA. A similar relation was found for PP and PI (r=0.32, p<0.001) or RI (r=0.30, p<0.001). Age, diabetes and hypertension, but not chronic tobacco smoking, interfered with MCA flow parameters. In multivariate adjusted regression analysis, PP was related to both PI and RI of MCA (p<0.001). In similar models, increased PWV was related to PI (p=0.007), but not RI (p=0.08) of MCA.


CONCLUSIONS
Increased PI and RI of MCA are closely related to measures of increased aortic stiffness.
Kwater
Aleksander
A
Department of Internal Medicine and Gerontology, Jagiellonian University, Kraków, Poland. ajkwater@interia.pl
Gasowski
Jerzy
J
Gryglewska
Barbara
B
Wizner
Barbara
B
Grodzicki
Tomasz
T
D000328:Adult; D000368:Aged; D001011:Aorta / Q000000981:diagnostic imaging / Q000503:physiopathology; D001158:Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D005602:France; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D011674:Pulse; D014463:Ultrasonography; D014655:Vascular Resistance
D002245:Carbon Dioxide