急性心肌梗死致心源性休克绵羊模型中体外膜氧合对左心室血流动力学的影响OA

Objective To investigate the effects of venous-arterial membrane oxygenation(V-A ECMO)on left ventric-ular hemodynamics in a sheep model of cardiogenic shock induced by acute myocardial infarction.Methods Six healthy adult male Small-tailed Han sheep were included to establish an ischemic shock model,followed by V-A ECMO support.Pressure-vol-ume loop(PV-Loop)and echocardiography techniques were employed to dynamically monitor key hemodynamic parameters,in-cluding left ventricular preload,afterload,and cardiac function,during the baseline period,shock period,and V-A ECMO support period.Results All six experimental sheep were successfully modeled,survived with V-A ECMO support,and completed the entire experimental procedure.Pressure-volume loop(PV-Loop)data showed that stroke work(SW),cardiac output(CO),and stroke volume(SV)significantly decreased compared to the shock period(P<0.001).No significant difference was observed in ejection fraction(EF)compared to the shock period.Volumetric parameters,including maximum volume(Vmax),minimum vol-ume(Vmin),end-systolic volume(Ves),and end-diastolic volume(Ved),all significantly decreased(P<0.001).Among pressure parameters,maximum pressure(Pmax)and developed pressure(Pdev)showed a decreasing trend(P<0.05),while no statistical differences were found in minimum pressure(Pmin),mean pressure(Pmean),end-systolic pressure(Pes),or end-diastolic pres-sure(Ped).Echocardiography data revealed that left atrial volume(LAV)significantly decreased compared to the shock period(P=0.020).Left ventricular end-systolic volume(LVESV)also markedly decreased(P=0.041).Left ventricular ejection fraction(LVEF)remained at a relatively low level(35.5%)without significant improvement compared to the shock period.The maximum aortic valve velocity(AV Vmax)exhibited a decreasing trend during the V-A ECMO support period.Myocardial strain parameters showed no significant differences between the V-A ECMO support and shock periods.Strain bull's-eye plots indicat-ed partial recovery of segmental strain values,suggesting a potential early trend of regional functional recovery.Conclusion In a V-A ECMO supported acute cardiogenic shock model,V-A ECMO effectively reduced left ventricular volume load(Vmax,Vmin,Ves,Ved)and alleviated ventricular dilation,while also decreasing myocardial oxygen demand by reducing cardiac work(SW,CO,SV).The decline in certain pressure parameters(Pmax,Pdev)suggests a possible reduction in wall stress,creating favorable conditions for myocardial recovery.Although overall cardiac function did not show significant improvement in the short term,partial recovery trends were observed in certain myocardial segments,demonstrating the therapeutic potential of V-A ECMO support.