Abstract 11335: Therapeutic Hypothermia Improves Cardiac Function After Successful Resuscitation From Cardiac Arrest in a Rat Model of Myocardial Infarction

Abstract

Introduction: We previously demonstrated that hypothermia improves post-resuscitation myocardial function in cardiac arrest animal models without coronary artery disease. In the present study, we investigated the effects of therapeutic hypothermia on post resuscitation myocardial function in a more clinically relevant rat model of myocardial infarction. Hypothesis: The therapeutic hypothermia improves post-resuscitation myocardial function after cardiac arrest and cardiopulmonary resuscitation in a rat model of myocardial infarction. Methods: Myocardial infarction was produced by left coronary artery (LCA) ligation 90 min prior to induction of ventricular fibrillation (VF). CPR with mechanical ventilation and precordial compression was initiated after 6 min of untreated VF. Defibrillation was attempted after 8 min of CPR. Animals were randomized into 2 groups: (1) Myocardial infarction-Normothermia group (MI-NT group, n=6), the core temperature was maintained at 37.0±0.2°C during resuscitation and next 4 hours after resuscitation; (2) Myocardial infarction-Hypothermia group (MI-HT group, n=6), the core temperature was maintained at 32.0±0.5°C during resuscitation and next 4 hours after resuscitation. Results: All animals were resuscitated successfully. Post-resuscitation ejection fraction (EF) and cardiac output (CO) were significantly greater in animals treated with hypothermia. ( p <0.01, Figure 1 and 2). Conclusions: Therapeutic hypothermia significantly reduces the severity of post-resuscitation myocardial systolic dysfunction in a rat model of myocardial infarction.