Stroke, Vol 16, 998-102, Copyright © 1985 by American Heart Association
PS Lacy and AM Earle
Sudden death may follow subarachnoid hemorrhage which indicates involvement
of neural mechanisms connected with the cardiovascular system. Since
various regions of the brain mediate blood pressure and heart rate changes,
these parameters and heart rhythm could be affected due to a subarachnoid
hemorrhage near the circle of Willis which surrounds the hypothalamus, the
highest center for autonomic control. To investigate this in the control
group, intracranial pressure, blood pressure, and electrocardiogram were
measured before and after a simulated subarachnoid hemorrhage; blood
pressure and electrocardiogram were measured following midcollicular
lesions in the decerebrate group both before and after a subarachnoid
hemorrhage. The results demonstrate that an increase in systemic arterial
blood pressure and premature ventricular contractions (with respect to
unlesioned group, p less than 0.04) are mediated by forebrain areas and
require the integrity of neuroanatomical connections with structures that
are caudal to the midbrain. Since bradycardia and other
electrocardiographic abnormalities could still be produced after
midcollicular lesioning it is suggested that they can be mediated via the
brainstem only without involvement of more rostral areas and may occur due
to increased intracranial pressure.
ARTICLES
Central neural control of blood pressure and cardiac arrhythmias during subarachnoid hemorrhage in rats
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