Functional effects of acute coronary occlusion and catecholinergic stimuli on the isolated normothermic hemoperfused porcine heart.
The aim of this study was to characterize functional parameters in the isolated and normothermic hemoperfused porcine beating heart model after pathophysiological stimuli for extended perfusion periods. Hearts were prepared and connected to a specially developed perfusion equipment, which simultaneously allowed perfusion with warm autologous blood as well as blood dialysis. Two groups were established: group A (12 hearts: no intervention) and group B (6 hearts: occlusion of the ramus circumflexus of the left coronary artery for 2 hours). Blood gas analyses and oxymetry were performed at baseline and every 30 min during a 6 hours perfusion period. Coronary perfusion pressure (CPP) and blood flow (CBF), right and left ventricular pressure, blood and dialyzate pH-values, and temperature were monitored online by a microcontroller. A steady state regarding the CPP and the CBF was achieved after 1 hour of perfusion for both groups. In group B, CPP increased during occlusion. Comparison of both groups showed no significant differences in the bicarbonate and sodium levels in blood and dialyzate. The potassium concentration in blood and dialyzate increased in both groups constantly during the experiments. No clear alteration of the oxygen consumption was observed. Lactate levels in blood and dialyzate increased during occlusion as did the aspartataminotransferase (AST) venous levels (both determined only for group B). Four concentrations of norepinephrine were injected into the stem of the coronary arteries (10, 20, 40, 80 microg). A clear inotropic effect of this hormone on right and left ventricular pressure was observed. It was concluded that longer perfusion periods and simulation of myocardial infarction for a clinically relevant period can be performed using this model. In addition, right and left ventricular function appear to be well preserved in this model, since the isolated porcine heart responded to norepinephrine stimuli.
Nogueira
Ana Cristina
AC
Department of Toxicology, Institute of Clinical Pharmacology and Toxicology, Benjamin Franklin Medical Center, Freie Universität Berlin, Berlin, Germany.
Ast
Inga
I
Patone
Gianino
G
Perschel
Frank Holger
FH
Grimm
Daniela
D
Paul
Martin
M
D000208:Acute Disease; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D001769:Blood; D001831:Body Temperature; D003327:Coronary Disease / Q000503:physiopathology*; D005260:Female; D006321:Heart / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology*; D009929:Organ Size; D010477:Perfusion; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013268:Stimulation, Chemical; D034421:Sus scrofa; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D001639:Bicarbonates; D014662:Vasoconstrictor Agents; D019344:Lactic Acid; D012964:Sodium; D011188:Potassium; D009638:Norepinephrine