Beta-adrenergic blockade during severe ischemia.
OBJECTIVE
To examine the effect of acebutolol, a beta-adrenergic-receptor blocker, on severe regional myocardial ischemia, specifically the effects on regional myocardial function and metabolism.


METHODS
Randomized study.


METHODS
Animal laboratory of the Department of Anesthesiology and Critical Care, University of Stellenbosch Medical School.


METHODS
Anesthetized open-chest pig model (n = 18).


METHODS
Regional left ventricular function and metabolism were evaluated. Severe stenosis was applied to the left anterior descending coronary artery. After establishing regional myocardial ischemia, acebutolol was administered intravenously, and results were compared with controls who did not receive acebutolol. Animals were prospectively randomized to 1 of the groups.


RESULTS
Regional myocardial function and metabolism were assessed by end-systolic pressure relationship, regional systolic shortening, postsystolic shortening, regional myocardial oxygen consumption, and lactate dynamics. Coronary blood flow was determined with a Doppler flow probe. Results indicated that acebutolol increased regional myocardial blood flow, and this resulted in less severe regional myocardial ischemia, improved function, and an increase in regional myocardial oxygen consumption.


CONCLUSIONS
The beta-Adrenergic-receptor antagonist was successful in reducing regional myocardial ischemia in this model. This reduction was achieved by an increase in coronary blood flow, which resulted in an improvement in regional mechanical function and an increase in oxygen consumption.
Coetzee
Andre
A
Department of Anesthesiology and Critical Care, School of Medicine, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, South Africa. arc1@sun.ac.za
Coetzee
Gert
G
D000070:Acebutolol / Q000627:therapeutic use*; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000818:Animals; D003326:Coronary Circulation / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D019344:Lactic Acid / Q000378:metabolism; D017202:Myocardial Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D013552:Swine; D016277:Ventricular Function, Left / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D019344:Lactic Acid; D000070:Acebutolol