Abstract P48: Comparison of Myocardial Function Between Global Myocardial Ischemia of Cardiac Arrest and Regional Myocardial Ischemia in Rats
Background: Both global myocardial ischemia following cardiac arrest (CA) and regional myocardial ischemia induced by left anterior descending coronary artery (LAD) occlusion lead to myocardial dysfunction following reperfusion. We therefore sought to compare myocardial function during the reperfusion interval following resuscitation from cardiac arrest or reperfusion from LAD occlusion. We hypothesized that myocardial dysfunction would be more severe in animals resuscitated from cardiac arrest in comparison to animals subjected to LAD ligation.
Methods: Ten male Sprague-Dawley rats weighing 450–550g were anesthetized, intubated, and mechanical ventilated. Animals were then randomized to:
8 min of untreated cardiac arrest followed by 8 min of CPR;
45 min of LAD occlusion followed by 4 hour of reperfusion.
Myocardial function, including ejection fraction (EF), dP/dt40 and −dP/dt were monitored.
Results: All animals subjected to either cardiac arrest/CPR or LAD occlusion/reperfusion survived for the 4 hour interval of observation. However, animals which underwent cardiac arrest/CPR presented significantly lower EF, dP/dt40 and higher −dP/dt in comparison to animals subjected to LAD ligation/reperfusion (P<0.05).
Conclusion: Myocardial dysfunction was significantly more severe following global myocardial ischemia even though the duration of ischemia was significantly short.