Effects of regional myocardial stunning on systemic hemodynamics and myocardial oxygen balance / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of regional myocardial stunning on systemic hemodynamics and myocardial oxygen balance Methods Thirty three open chest anesthetized dogs were subjected to 15min left anterior descending (LAD) coronary artery occlusion under normal temperature, the systemic hemodynamics, coronary blood flow (CBF), myocardial oxygen delivery(MDO 2) and consumption(MVO 2)were determined following reperfusion Results MAP decreased slightly during LAD occlusion, but returned to baseline following reperfusion CO, SV and LVSWI reduced rapidly after LAD occlusion, increased slightly 5min following reperfusion, followed by a more severe reduction , with the progressive increases of SVR and PVR during whole periods At the early stage of reperfusion (5min), CBF, MDO 2 and MVO 2 increased significantly, then decreased rapidly 10min following reperfusion Myocardial oxygen extraction rate remained stable during whole procedures Histological changes of ischemic area 30min following reperfusion showed interstitial and intracellular edema, mitochondrial vacuolization, and capillary stasis under electronic microscopy Conclusions Regional myocardial stunning may resulte in sinificant changes of systemic hemodynamics; at the early stage of reperfusion, oxygen consumption paradox occurres ,but MDO 2 matches MVO 2 10min following myocardial reperfusion