Effects Of Mild Hypothermia Combined Mivazerol And U50488H On Cardiac Function At Early Stage Of Postresuscitafion In Rabbits

Objective:Postresuscitation myocardial dysfunction contributes to the high fatality rate following successful resuscitation. The purpose of this animal research to investigate the effect of mild hypothermia combined mivazerol and U50488H on cardiac function at early stage of postresuscitation in rabbits, and to explore if they can reduce the myocardial damage and improve cardiac dysfunction after resuscitation. Methods:Ventricular fibrillation(VF) was induced by the external electricity, After setting up rabbit model of cardiopulmonary resuscitation,32rabbits were randomly divided into four groups. group A:normothermic resuscitation group,in which animals were performed standard CPR after cardiac arrest, administration of the standard doses of epinephrine (30ug/kg) during CPR; group B:mild hypothermia resuscitation group, in which animals were cooled to32-34℃after successful ROSC; group C:mivazerol combined U50488H group, administration of mivazerol(50ug/kg) and U50488H(1.5mg/kg) during CPR. group D:mild hypothermia combined mivazerol and U50488H group, administration of mivazerol(50ug/kg) and U50488H(1.5mg/kg) during CPR, and animals were cooled to32-34℃after successful ROSC. The left ventricular end-diastolic pressure(LVEDP),left ventricular pressure rise and fall rate(peak±dp/dt), serum concentrations of H-FABP were observed, In addition, animals were sacrificed on4hours after resuscitation, The ICAM-1expression on myocardial cells were detected by immunohistochemical methods. Results:(1) compared with group A,The LVEDP and peak±dp/dt of group B and C were singnificant derefences on120min,180min and240min after ROSC(P<0.05); compared with group B and C, The LVEDP and peak±dp/dt of group D were singnificant derefences on60min,120min,180min,and240min after ROSC(P<0.05).(2) serum concentrations of H-FABP reached the highest value on recovery after60min in each group..compared with group A, B, C, In group D,The serum concentrations of H-FABP singnificantlly decreased on120min,180min.and240min after ROSC(P<0.05);(3) expression of ICAM-1in four groups shows:a large number of ICAM-1positive cells can be seen in group A. compared with group A. ICAM-1positive cells in group B and C were less than group A.A very small amount of ICAM-1positive cells can be seen in group D; Compared with group A expression of ICAM-1was Significantly different in group B and C after resuscitation(P＜0.05), Compared with group B and C, expression of ICAM-1was Significantly different in group D after resuscitation (P<0.05). Conclusions:Mild hypothermia combined mivazerol and U50488H can improve Postresuscitation hemodynamics indexes and reduce serum concentrations of H-FABP at early stage of postresuscitafion, and reduce expression of ICAM-1in myocardial cells,. so that they can reduce myocardial damage and inflammation,and improve cardiac dysfunction after resuscitation.