title: Normotherm continuous blood cardioplegia for 4 hours in an in vivo pig model.
abstract: Warm, continuous blood cardioplegia should theoretically maintain cardiac arrest for hours without ischaemic or hypothermic injury. In the absence of in vivo studies of myocardial metabolism and ultrastructural and/or functional preservation during and after more than 2 hours of cardiac arrest and after weaning from bypass, we devised a porcine model with a closed extracorporeal circuit for the heart alone. Normothermic blood cardioplegia was administered antegrade and recirculated for 2 or 4 hours, each in seven pigs. After aortic declamping all were successfully weaned from bypass and reperfused for 1 hour. Thereafter we found no significant intergroup difference in haemodynamic characteristics (average fall in mean arterial pressure 31.7 +/- 3.2% and 26.9 +/- 2.6%) or blood analyses. After 5 and 60 minutes of cardiac arrest there was minimal lactate production (5.7 +/- 10.7 and 0.5 +/- 10.5 nmol/l, respectively), whereas in the remainder of the arrest period there was lactate uptake, indicating aerobic heart metabolism. Our setup avoids systemic hyperkalaemia, gives good cardiac protection with no deterioration between 2 and 4 hours and is well suited for studies on the quiescent, blood-perfused oxygenated heart.
authors.affiliation: Department of Surgery, Tromsø University Hospital, University of Tromsø Norway.
authors.forename: O
authors.initials: O
authors.lastname: Irtun
authors.forename: T
authors.initials: T
authors.lastname: Broks
authors.forename: K
authors.initials: K
authors.lastname: Hansen
authors.forename: U
authors.initials: U
authors.lastname: Larsen
authors.forename: J P
authors.initials: JP
authors.lastname: Solbø
authors.forename: T S
authors.initials: TS
authors.lastname: Larsen
authors.forename: D
authors.initials: D
authors.lastname: Sørlie
mesh_terms: D000818:Animals; D001794:Blood Pressure; D003250:Constriction; D003331:Coronary Vessels / Q000737:chemistry; D003402:Creatine Kinase / Q000097:blood; D006324:Heart Arrest, Induced; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008954:Models, Biological; D013552:Swine
chemical_list: D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase