title: Heart rate limitation and cardiac unloading in sevoflurane post-conditioning.
abstract: BACKGROUND
  Sevoflurane post-conditioning (SePost) has been found to alleviate ischemic myocardial reperfusion injury through the activation of prosurvival kinases. Lowered myocardial oxygen demand from reduced cardiac work may also contribute to cardioprotection, and is much less well-studied. Our aim was to examine the simultaneous effects of SePost on cardiac work (here, rate-pressure product, RPP) and myocardial infarct size in a porcine model.
  
  
  METHODS
  Anesthetized 25 kg pigs were randomly allocated to two groups and underwent 45 min regional coronary artery balloon occlusion and subsequent 2 h reperfusion. SePost (n = 10) was given as sevoflurane 1.5-3% end-tidal concentration during reperfusion while controls (n = 12) were untreated. Aortic blood pressure was measured directly, while mixed-venous oxygen saturation and cardiac output were measured in the pulmonary artery. Cardiac work was determined as RPP. Post-mortem, histologic myocardial infarct size (IS), and area at risk were determined in transverse heart slices after tetrazolium stain.
  
  
  RESULTS
  Myocardial infarct size was reduced from (control) 55.0 (mean) ± 13.6% (standard deviation) to 32.5 ± 13.4% in group SePost (P = 0.0009). During reperfusion, SePost resulted in lower heart rate (P = 0.0003), cardiac output (P = 0.0123), mixed-venous oxygen saturation (P = 0.0103), blood pressure, and RPP (P < 0.0001). RPP was highly correlated to IS (P = 0.0055).
  
  
  CONCLUSIONS
  SePost (1.5-3%) reduced infarct size after regional myocardial ischemia in vivo and reduced cardiac work was significantly correlated to myocardial salvage.
authors: Department of Anesthesia and Intensive Care, Aarhus University Hospital, Skejby, Denmark. jens.rolighed@ki.au.dk
authors: J R
authors: JR
authors: Larsen
authors: K
authors: K
authors: Sivesgaard
authors: S D
authors: SD
authors: Christensen
authors: J L
authors: JL
authors: Hønge
authors: J M
authors: JM
authors: Hasenkam
mesh_terms: D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics / Q000494:pharmacology*; D000818:Animals; D006328:Cardiac Catheterization; D002302:Cardiac Output / Q000187:drug effects; D017023:Coronary Angiography; D054059:Coronary Occlusion / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006439:Hemodynamics / Q000187:drug effects; D057775:Ischemic Postconditioning / Q000379:methods*; D008738:Methyl Ethers / Q000493:pharmacokinetics / Q000494:pharmacology*; D009203:Myocardial Infarction / Q000473:pathology / Q000517:prevention & control; D015425:Myocardial Reperfusion; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control; D010100:Oxygen / Q000097:blood; D000077149:Sevoflurane; D013552:Swine
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D010100:Oxygen