Reduction of myocardial reperfusion injury by high-dose beta-blockade with esmolol.
BACKGROUND
Myocardial ischemia reperfusion injury may be reduced by beta-blockade. However, how myocardial salvage is affected when beta-blockade is limited to the reperfusion period is unknown. We investigated the impact of CPB and esmolol during reperfusion on infarct size and left ventricular function in two different experimental models of acute myocardial ischemia.


METHODS
In open-chest dogs, myocardial ischemia was induced by LAD occlusion in both studies. In study 1, infarct size (TTZ stain) and myocardial water content (MWC, microgravimetry) were determined, comparing reperfusion with blood and esmolol to blood without additives. Study 2 investigated the impact of esmolol on LV function (sonomicrometry, echocardiography) and MWC (microgravimetry) compared to warm blood cardioplegia in a more clinically oriented model.


RESULTS
Infarct size and MWC in reperfused myocardium were significantly reduced by esmolol during reperfusion. Global LV function was better preserved in the esmolol group, whereas no difference was seen regarding regional function.


CONCLUSIONS
Myocardial salvage may be significantly enhanced by CPB and esmolol, even when treatment with esmolol is initiated as late as with the onset of reperfusion.
Geissler
H J
HJ
Department of Cardiothoracic Surgery, University of Cologne, Germany. hans.geissler@medizin.uni-koeln.de
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000704:Analysis of Variance; D000818:Animals; D002315:Cardiopulmonary Bypass; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004489:Edema, Cardiac / Q000517:prevention & control; D006324:Heart Arrest, Induced / Q000379:methods; D009203:Myocardial Infarction / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009206:Myocardium / Q000473:pathology; D011412:Propanolamines / Q000627:therapeutic use*; D016277:Ventricular Function, Left / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C036604:esmolol