Establishment of a porcine right ventricular infarction model for cardioprotective actions of xenon and isoflurane.
BACKGROUND
Right ventricular (RV) function is an important determinant of post-operative outcome. Consequences of RV infarction might be limited by pre-conditioning with volatile anesthetic drugs. Therefore, we used a porcine model of RV ischemia and reperfusion (IR) injury to study the influence of isoflurane and xenon on the extent and degree of myocardial injury.


METHODS
IR injury was induced by a 90-min ligation of the distal right coronary artery and 120-min reperfusion in thiopental anesthetized pigs. A control group (n=12) was compared with two groups, which received either 0.55 minimum alveolar concentration (MAC) isoflurane (n=10) or xenon (n=12) starting 60 min before ischemia. Myocardial injury was described by three criteria: the infarct size related to area at risk (IS/AAR), the infiltration of neutrophils as determined by myeloperoxidase (MPO) activity, and the plasma levels of tumor necrosis factor alpha (TNFalpha), interleukin 6 (IL-6), myoglobin and troponin-T (TnT).


RESULTS
IS/AAR was reduced from 58.3+/-6.2% in the control group to 41.8+/-7.8% after isoflurane and 42.7+/-8.5% after xenon pre-treatment, which equals an absolute reduction of 16.5% [95% confidence interval (CI): 10.9-22.1] and 15.5% (95% CI: 10.1-20.9). The maximum increase of TnT could be observed within the xenon group. Both treatment groups were characterized by lower MPO activity, in the infarct and periinfarct region and lower plasma concentrations of TNFalpha and IL-6.


CONCLUSIONS
It could be demonstrated for the first time in a model of RV infarction that the continuous application of isoflurane or xenon before, during and after ischemia reduced the extent (size) and severity (inflammation) of myocardial injury.
Hein
M
M
Department of Anesthesiology, University Hospital of Aken, Aachen, Germany. mhein@ukaachen.de
Roehl
A B
AB
Baumert
J H
JH
Bantes
B
B
Bleilevens
C
C
Bernstein
N
N
Steendijk
P
P
Rossaint
R
R
D000792:Angiography; D000818:Animals; D015415:Biomarkers / Q000097:blood; D004195:Disease Models, Animal; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000201:enzymology / Q000601:surgery; D006439:Hemodynamics; D007530:Isoflurane / Q000494:pharmacology*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000201:enzymology / Q000601:surgery; D009195:Peroxidase / Q000378:metabolism; D012307:Risk Factors; D034421:Sus scrofa; D013552:Swine; D014978:Xenon / Q000494:pharmacology*
D015415:Biomarkers; D014978:Xenon; D007530:Isoflurane; D009195:Peroxidase