Document Detail


Effects of isoflurane on regional coronary blood flow and myocardial tissue pressure in chronically instrumented dogs.
MedLine Citation:
PMID:  7943839     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: The effects of isoflurane on distribution of transmural blood flow and transmural intramyocardial tissue pressure (IMP) were studied in chronically instrumented dogs, to address following aims: (1) to evaluate the direct effects of isoflurane on transmural blood flow distribution in the absence of compounding effects of baseline anesthetics, acute surgery, and indirect effects caused by changes in systemic blood pressures and heart rate--factors that were not well controlled in the past studies; (2) to examine the relation between transmural myocardial perfusion pressure and concurrent changes in transmural blood flow distribution during isoflurane anesthesia; and (3) to evaluate the effects of isoflurane on transmural myocardial oxygen supply-demand relation. METHODS: Dogs were allowed to recover at least 1 week after surgery for instrumentation. Blood flow of the left anterior descending coronary artery and subendocardial and subepicardial blood flows, regional IMPs, regional segmental dimension, heart rate, aortic pressure and left ventricular pressure were measured while dogs were awake and during 1.3% isoflurane anesthesia, with and without correction of heart rate and aortic pressure. Concurrently regional myocardial perfusion pressure, regional myocardial stroke work, and systolic pressure time index were calculated, based on direct measurements of IMP in subendocardium and subepicardium. RESULTS: Without correction of aortic pressure, neither left anterior descending coronary artery flow nor transmural blood flow distribution was altered with isoflurane. When aortic pressure and heart rate were corrected to the awake values, left anterior descending coronary artery flow increased (37 +/- 2%) and the increase was preferentially distributed to subendocardium, resulting in a shift in transmural blood flow. The subendocardial/subepicardial blood flow ratio increased from 1.2 +/- 0.3 to 1.4 +/- 0.4 (p, 0.05). The transmural blood flow changes were closely related to changes in regional myocardial perfusion pressure ratio between subendocardium and subepicardium (r = 0.76, P < 0.001). Concurrent with marked increases in blood flow (55 +/- 4% increase), regional myocardial stroke work and systolic pressure time index of subendocardium were decreased more than 50% with isoflurane, resulting in a favorable subendocardial oxygen supply-demand balance. CONCLUSIONS: Isoflurane is a coronary vasodilator and redistributes blood flow in favor of subendocardium and depresses subendocardial work when heart rate and aortic pressure are controlled. These changes in regional myocardial blood flow, regional myocardial stroke work, and systolic pressure time index appear to be a result of changes in regional IMP.
Authors:
Y D Kim; K Heim; Y N Wang; D Lees; A K Myers
Related Documents :
7869249 - Cardiac contraction and intramyocardial venous pressure generation in the anaesthetized...
160469 - Effects of 2-nicotinamidoethyl nitrate on the cardiovascular system.
6183019 - Renin-angiotensin system inhibition in acute myocardial infarction in dogs. effects on ...
2710789 - The pattern of delivery and distribution of coronary venous retroinfusate in canine hea...
804809 - Prinzmetal's variant angina: hemodynamic and angiographic observations during pain.
9085349 - Role of nitric oxide (no) in the regulation of coronary circulation.
15022819 - Adhesion of the subacromial bursa may cause subacromial impingement in patients with ro...
10097829 - Variation in tau, the time constant for isovolumic relaxation, along the left ventricul...
7326169 - Effects of nitrous oxide and oxygen on tracheal tube cuff gas volumes.
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Anesthesiology     Volume:  81     ISSN:  0003-3022     ISO Abbreviation:  Anesthesiology     Publication Date:  1994 Oct 
Date Detail:
Created Date:  1994-11-08     Completed Date:  1994-11-08     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  875-87     Citation Subset:  AIM; IM    
Affiliation:
Department of Anesthesiology, Georgetown University Medical Center, Washington, D.C. 20007.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / drug effects,  physiology
Blood Vessels / drug effects,  physiology*
Coronary Circulation / drug effects,  physiology*
Dogs
Female
Heart / drug effects,  physiology*
Heart Rate / drug effects,  physiology
Hemodynamics / drug effects,  physiology
Isoflurane / pharmacology*
Male
Regional Blood Flow / drug effects,  physiology
Stroke Volume
Ventricular Function, Left / drug effects,  physiology
Grant Support
ID/Acronym/Agency:
GM42045/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
26675-46-7/Isoflurane

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  High thoracic epidural anesthesia does not alter airway resistance and attenuates the response to an...
Next Document:  Mutations conferring new patterns of sensitivity to volatile anesthetics in Caenorhabditis elegans.