Xenon improves recovery from myocardial stunning in chronically instrumented dogs.
In this study we tested the hypothesis that inhalational administration of xenon improves recovery from myocardial stunning. Ten dogs were chronically instrumented for measurement of heart rate; left atrial, aortic, and left ventricular pressure; coronary blood-flow velocity; and myocardial wall-thickening fraction. Regional myocardial blood flow was determined with fluorescent microspheres. Catecholamine plasma levels were measured by high-performance liquid chromatography. An occluder around the left anterior descending artery (LAD) allowed the induction of a reversible LAD ischemia. Animals underwent 2 experimental conditions in a randomized crossover fashion on separate days: (a) 10 min of LAD occlusion under fentanyl (25 microg. kg(-1). h(-1)) and midazolam (0.6 mg. kg(-1). h(-1)) (control) and (b) a second ischemic episode under the same basal anesthesia with concomitant inhalational administration of 75 +/- 1 vol% xenon (intervention). Anesthesia was induced 35 min before LAD occlusion and was discontinued after 20 min of reperfusion. Dogs receiving xenon showed a significantly better recovery of wall-thickening fraction up to 12 h after ischemia. The increase in plasma epinephrine during emergence from anesthesia and in the early reperfusion period was significantly attenuated in the xenon group. There were no differences between groups concerning global hemodynamics, blood-flow velocity, or regional myocardial blood flow. In conclusion, inhalational administration of 75 vol% xenon improves recovery from myocardial stunning in chronically instrumented dogs under fentanyl/midazolam anesthesia.
Grosse Hartlage
Maike A
MA
*Department of Anaesthesiology and Intensive Care and †Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Münster, Münster, Germany.
Berendes
Elmar
E
Van Aken
Hugo
H
Fobker
Manfred
M
Theisen
Marc
M
Weber
Thomas P
TP
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D004285:Dogs; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D017682:Myocardial Stunning / Q000188:drug therapy* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000187:drug effects; D014978:Xenon / Q000494:pharmacology / Q000627:therapeutic use*
D014978:Xenon; D004837:Epinephrine