Document Detail

Effects of age and coronary artery disease on cerebrovascular reactivity to carbon dioxide in humans.
MedLine Citation:
PMID:  20715736     Owner:  NLM     Status:  MEDLINE    
Alterations in cerebrovascular reactivity to CO2, an index of cerebrovascular function, have been associated with increased risk of stroke. We hypothesised that cerebrovascular reactivity is impaired with increasing age and in patients with symptomatic coronary artery disease (CAD). Cerebrovascular and cardiovascular reactivity to CO2 was assessed at rest and during hypercapnia (5% CO2) and hypocapnia (hyperventilation) in subjects with symptomatic CAD (n=13) and age-matched old (n=9) and young (n=20) controls without CAD. Independent of CAD, reductions in middle cerebral artery blood velocity (transcranial Doppler) and cerebral oxygenation (near-infrared spectroscopy) were correlated with increasing age (r = -0.68, r = -0.51, respectively, P < 0.01). In CAD patients, at rest and during hypercapnia, cerebral oxygenation was lower (P < 0.05 vs. young). Although middle cerebral artery blood velocity reactivity was unaltered in the hypercapnic range, middle cerebral artery blood velocity reactivity to hypocapnia was elevated in the CAD and age-matched controls (P < 0.01 vs. young), and was associated with age (r = 0.62, P < 0.01). Transient drops in arterial PCO2 occur in a range of physiological and pathophysiological situations, therefore, the elevated middle cerebral artery blood velocity reactivity to hypocapnia combined with reductions in middle cerebral artery blood velocity may be important mechanisms underlying neurological risk with aging. In CAD patients, additional reductions in cerebral oxygenation may place them at additional risk of cerebral ischaemia.
S D Galvin; L A Celi; K N Thomas; T R Clendon; I F Galvin; R W Bunton; P N Ainslie
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Anaesthesia and intensive care     Volume:  38     ISSN:  0310-057X     ISO Abbreviation:  Anaesth Intensive Care     Publication Date:  2010 Jul 
Date Detail:
Created Date:  2010-08-18     Completed Date:  2010-09-14     Revised Date:  2011-04-25    
Medline Journal Info:
Nlm Unique ID:  0342017     Medline TA:  Anaesth Intensive Care     Country:  Australia    
Other Details:
Languages:  eng     Pagination:  710-7     Citation Subset:  IM    
Department of Cardiothoracic Surgery, Section of Surgery, University of Otago and Dunedin Hospital, New Zealand.
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MeSH Terms
Age Factors
Blood Flow Velocity
Carbon Dioxide / blood,  pharmacology*
Case-Control Studies
Cerebrovascular Circulation*
Coronary Artery Disease / physiopathology*
Hypercapnia / physiopathology*
Hypocapnia / physiopathology
Middle Aged
Middle Cerebral Artery / metabolism
Risk Factors
Spectroscopy, Near-Infrared
Ultrasonography, Doppler, Transcranial
Young Adult
Reg. No./Substance:
124-38-9/Carbon Dioxide

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