Clinical Physiology of Circulation

Chief Editor

Leo A. Bockeria, MD, PhD, DSc, Professor, Academician of Russian Academy of Sciences, President of Bakoulev National Medical Research Center for Cardiovascular Surgery


Цереброваскулярная реактивность у юношей с артериальной гипертензией

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Link: Clinical Physiology of Blood Circulaiton. 2013; (): -

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Abstract


Objective.
The ascertainment of peculiarities of cerebrovascular CO2 reactivity in adolescent males with arterial hypertension.
Material and methods. 14 young males with arterial hypertension and 12 healthy young males took part in the research. To estimate cerebrovascular reactivity we analyzed cerebral blood flow velocity in medial cerebral arteries on both sides (transcranial and Doppler monitoring) at rest, at hypercapnia (rebreathing), and hypocapnia (hyperventilation). In the course of monitoring partial pressure of CO2 at the end of expiration was estimated with the help of a capnograph, as well as mean hemodynamic arterial blood pressure was estimated by means of a continuous noninvasive measurement fr om beat to beat.
Results. Мean hemodynamic arterial blood pressure in adolescent males with arterial hypertension was higher than in healthy objects (109.7 (105.3; 112.8) mm Hg and 85.6 (80.7; 90.0) mm Hg correspondingly, p<0.001), wh ereas cerebral blood flow velocity did not differ. Cerebrovascular reactivity for hypocapnia in adolescent males with arterial hypertension was reduced as compared to that in healthy objects (-2.7 (-2.5; -3.1) %/mm Hg, and -3.1 (-2.9; -3.5) %/mm Hg correspondingly, p<0.05). Cerebrovascular reactivity for hypercapnia in adolescent males with arterial hypertension did not differ from that in healthy objects. Mean hemodynamic arterial blood pressure at arterial hypertension correlated more with cerebrovascular reactivity for hypercapnia and hypocapnia as compared to that in healthy objects (R=0.53 and 0.76 at arterial hypertension, R=0.45 and 0.68 in healthy objects, p<0.05).
Conclusion. Cerebrovascular reactivity declines at early stages of arterial hypertension development, and mostly at the expense of reduction of cerebral vessels reaction to hypocapnia. The evaluation of cerebrovascular reactivity for hypocapnia can be more useful to detect initial cerebral hemodynamics disorders at arterial hypertension as compared with general hypercapnic test.

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