ABSTRACT
Objective To characterize myocardial metabolism using positron emission tomography (PET) in porcine models of ventricular fibrillation cardiac arrest (VFCA) and asphyxiation cardiac arrest (ACA) after resuscitation.Methods Thirty-two healthy miniature pigs were randomized into two groups.The pigs of VFCA group (n =16) were subject to programmed electric stimulation to create a ventricular fibrillation cardiac arrest,and the pigs of ACA group (n =16) were subjected to endotracheal tube clamping to establish a cardiac arrest (CA).Once modeling was established,pigs with CA were left untreated for a period of 8 min.Two minutes following initiation of cardiopulmonary resuscitation (CPR),defibrillation was attempted until the restoration of spontaneous circulation (ROSC) was achieved or animals died.To assess myocardial metabolism,PET was performed before modeling,4 hrs and 24hrs after ROSC.To analyze 18F-FDG myocardial uptake in PET,the maximum standardized uptake value (SUVmax)) was measured.Results ROSC was obtained in 100％ of pigs in VFCA group and only 50％ in ACA group.The average survival time in VFCA pigs was significantly longer than that in ACA pigs (22.63 ± 0.95) hvs.(8.75 ± 2.54) h,P ＜0.01.VFCA pigs had better mean arterial pressure and cardiac output after ROSC than ACA pigs.Myocardial metabolism imaging using PET demonstrated that myocardial metabolism injuries after ACA were more severe and widespread than those after VFCA at 4 hrs and 24hrs after ROSC and SUVmax) was much higher in VFCA group than that in ACA group [4 h after ROSC:(1.9 ± 0.3) vs.(1.0 ± 0.4),P ＜ 0.01;24 hafterROSC:(2.4±0.6) vs.(1.2±0.5),P＜0.01].Conclusions Compared with VFCA,ACA causes more severe cardiac metabolism dysfunction associated with less successful resuscitation and shorter survival time;therefore they should be treated as different pathological entities.
ABSTRACT
Objective To determine the protective effect of isosorbidemononitrate (IM) on myocardial injury after restoration of spontaneous circulation (ROSC)in swine models of cardiac arrest induced by ventricular fibrillation.Methods The experiment was carried out in Animal Lab of Beijing Chao-Yang Hospital,Capital Medical University.Ventricular fibrillation was induced and untreated for 8 min in twenty WhuZhiShan piglets.CPR was performed until ROSC occurred.The animals were randomized (random number)into two groups:IMgroup (n =10)and control group (n =10).IM [2 μg/(kg· min)]or the equivalent volume in saline was administered respectively for 6 h after ROSC.Hemodynamics and post-resuscitation cardiac function were monitored until 24 h after ROSC. Echocardiography and transmission electron microscopy were useed at 72 h after ROSC.Results There was no significant difference in survival rate between the two groups.No significant differences in mean arterial pressures (mmHg)at ROSC 6 h (88.5 ±5.6 vs.87.8 ±6.0,P =0.790)and ROSC 24 h (89.3 ±3.8 vs.86.9 ± 5.0,P =0.245)between the two groups were found.Cardiac outputs (L/min)were significantly increased at ROSC 6 h (2.40 ±0.17 vs.1.60 ±0.14,P <0.01)and ROSC 24 h (2.49 ±0.17 vs.2.09 ±0.21,P<0.01);and ejection fraction at ROSC 72 h (0.67 ±0.08 vs.0.56 ±0.09,P =0.044)was improved too,and significant differences were found between the two groups.The ultra-structural myocardial injury was ameliorated in the MI group at 72 h after CPR observed by using electron microscopy.Conclusions IM can ameliorate post-resuscitation cardiac dysfunction in porcine models of cardiac arrest induced by ventricular fibrillation.
ABSTRACT
Objective To study the difference in post-resuscitation lung injury between cardiac arrest induced by anoxia and ventricular fibrillation in porcine model.Methods WuZhiShan inbred miniature pigs were randomly (random number) divided into the asphyxia (AS,n =24) and ventricular fibrillation group (VF,n =24).Cardiac arrest (CA) was induced by endotracheal tube clamping or programmed electric stimulation.Cardiopulmonary resuscitation (CPR) or defibrillation was performed for returning of spontaneous circulation (ROSC).Pulmonary perfusion/ventilation measured with isotope scanand positron emission tomography-computed tomography (PET-CT) scanning were done before and 4hrs after ROSC.The oxygenation index (OI),respiratory index (RI),oxygen delivery (DO2),blood lactic acid,and dynamic pulmonary compliance (Cdyn),airway resistance (Raw),extra-vascular lung water index (EVLWI),pulmonary vascular permeability index (PVPI),were measured before cardiac arrest,ROSC 0 h,ROSC15 min,ROSC 30 min,ROSC 1 h,ROSC 2 h,ROSC 4 h and ROSC 6 h.All pigs were sacrificed with euthanasia at ROSC 6 h and the lungs were dissected for observing histopathological changes.The level of Na +-K +-ATPase,Ca2+-ATPase,superoxide dismutase (SOD),Methane Dicarboxylic Aldehyde (MDA),Bcl-2,Bax,Caspase3 and apoptosis index (AI％) in lung were measured.Results The ROSC rate and ROSC 6hrs survival rate of in AS group was lower (P ＜0.01) than those of the VF group.The damages of lung in AS group were more severe than that in VF group by the results of enzymology and protein detection (Na +-K +-ATPase,Ca2 +-ATPase,SOD,MDA,Bax,Bcl-2 and Caspase3).AI％ was higher in AS group (P＜0.01).The deterioration of the indexes (OI,RI,DO2,Lac,Cdyn,Raw,EVLWI,PVPI) at all time points were more severe in AS group than those in VF group.Obvious filling-defect was found by the PET-CT scan of both groups,but not revealed by the isotope scan.Conclusions The lung injury after CA was closely related to the cause of CA rather than the external chest compression.Asphyxia induced more serious lung injury than ventricular fibrillation.