We have located links that may give you full text access.
JOURNAL ARTICLE
RESEARCH SUPPORT, NON-U.S. GOV'T
RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
REVIEW
Regulation of coronary vasomotor tone under normal conditions and during acute myocardial hypoperfusion.
Pharmacology & Therapeutics 2000 April
Ischemia generally has been assumed to cause maximal vasodilation of the coronary resistance vessels. However, recent observations have demonstrated that during ischemia, the coronary microvessels can retain some degree of vasodilator reserve and remain responsive to vasoconstrictor stimuli. Traditional understanding of coronary blood flow regulation envisioned an array of resistance vessels that respond homogeneously to local myocardial metabolic needs. Although coronary arterioles (<100 microm) do respond to myocardial metabolic activity, recent studies have demonstrated that up to 40% of total coronary resistance resides in small arteries 100-400 microm in diameter. Vasoconstriction of these small arteries is capable of decreasing blood flow, but they are minimally responsive to the metabolic effects of the resultant flow reduction. The lack of metabolic vasoregulation of the resistance arteries explains, at least in part, the observation that myocardial ischemia does not predictably cause maximal resistance vessel dilation. In addition, vasoconstrictor influences can compete with metabolic vasodilator activity in coronary arterioles. These findings suggest that pharmacologic vasodilators acting at the microvascular level might be therapeutically useful in patients with ischemic heart disease. Unfortunately, when myocardial ischemia results from a flow-limiting coronary stenosis, nonselective pharmacologic vasodilation of the resistance vessels can worsen subendocardial ischemia by decreasing intravascular pressure to produce coronary steal and by worsening of stenosis severity. Selective dilation of small arteries in ischemic regions might have potential for enhancing blood flow. A critical property of an effective agent is that it not interfere with metabolic vasoregulation at the arteriole level, so that dilation of small arteries in adequately perfused regions would be countered by compensatory vasoconstriction of the arterioles to prevent coronary steal.
Full text links
Related Resources
Trending Papers
Heart failure with preserved ejection fraction: diagnosis, risk assessment, and treatment.Clinical Research in Cardiology : Official Journal of the German Cardiac Society 2024 April 12
Proximal versus distal diuretics in congestive heart failure.Nephrology, Dialysis, Transplantation 2024 Februrary 30
Efficacy and safety of pharmacotherapy in chronic insomnia: A review of clinical guidelines and case reports.Mental Health Clinician 2023 October
World Health Organization and International Consensus Classification of eosinophilic disorders: 2024 update on diagnosis, risk stratification, and management.American Journal of Hematology 2024 March 30
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app