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Effect of Hypotension on Internal and External Carotid Blood Flow

1965; American Association of Neurological Surgeons; Volume: 23; Issue: 2 Linguagem: Inglês

10.3171/jns.1965.23.2.0191

1933-0693

John Stirling Meyer, Jyoji Handa, Peter M. Huber, Kouzo YOSHIDA,

Heart Rate Variability and Autonomic Control

T uE b lood flow in t h e i n t e r n a l c a r o t i d a r t e r y a n d t h a t in t he e x t e r n a l c a r o t i d a r t e r y differs in t h e response to changes in sy s t emic b lood p ressure , CO2 i n h a l a t i o n or t h e a d m i n i s t r a t i o n of p a p a v e r i n e a n d o t h e r drugs . I n a p r ev ious s t u d y , 4 i t was a p p a r e n t t h a t t h e flow in t h e i n t e r n a l c a r o t i d a r t e r y r e m a i n e d s t ab le d u r i n g m o d e r a t e changes in b lood pressure , b u t t h a t t h e flow in t h e ext e rna l c a r o t i d a r t e r y was m u c h m o r e dep e n d e n t on b lood p res su re ; i ndeed , s l ight changes in b lood p ressu re c o n s i d e r a b l y inf luenced e x t e r n a l c a r o t i d flow. Di f fe rences of th i s sor t m i g h t inf luence t h e response of these vessels d u r i n g h y p o v o l e m i c h y p o t e n sion, p a r t i c u l a r l y when t h e y f u n c t i o n as a ce rebra l co l l a t e ra l c i r cu l a t i on fo l lowing t h e occlusion of t he o p p o s i t e c a ro t i d a r t e r y . T h e p r e s e n t s t u d y was des igned to m e a sure ce r eb ra l ( i n t e rna l ca ro t id ) a n d ex t r a ce rebra l ( ex te rna l c a ro t i d ) b lood flow before a n d a f t e r c a r o t i d occ lus ion d u r i n g i n d u c e d h y p o v o l e m i c h y p o t e n s i o n . Th i s b e i n g de te r mined , t h e p a r t p l a y e d b y t h e s y m p a t h e t i c i n n e r v a t i o n in t h e dif ferences of response of t he two s y s t e m s was examined .