Abstract 11081: Propranolol Pretreatment Reduces the Severity of Post-Resuscitation Left Ventricular Dysfunction Caused by Epinephrine in a Rat Cardiac Arrest Model
Introduction: Studies have demonstrated that epinephrine significantly increases the severity of post-resuscitation myocardial dysfunction and reduces the duration of survival. The detrimental effects of epinephrine are closely related to its β-actions. In the present study, we investigated the effects of epinephrine on post-resuscitation systolic and diastolic function with or without β-blocker.
Hypothesis: Propranolol pretreatment reduces the severity of post-resuscitation left ventricular dysfunction caused by epinephrine.
Method: Eighteen male Sprague Dawley rats weighing between 450-550g were randomized into three groups: 1) Placebo group; 2) Epinephrine (20ug/kg) group; 3) Propranolol (1mg/kg) pretreatment + epinephrine (20ug/kg) group. Ventricular fibrillation (VF) was induced. After 8 mins of VF, CPR was initiated for 8 mins, and defibrillation was then attempted. The isovolumetric contraction index (ICT/ET) and isovolumetric relaxation index (IRT/ET) were measured by echocardiography at baseline and hourly for 4 hours following ROSC. Neurological Deficit Scores (NDS) and the duration of survival were observed for 120 hours.
Result: Except one in the placebo group, all animals were resuscitated. There were no significant difference in post-resuscitation myocardial systolic function as measured by ICT/ET between the three groups during the first 2 hours after ROSC. However, a significantly better ICT/ET was observed in the propranolol pretreatment group at PR 3-4 hours (Table). A significantly better post-resuscitation myocardial diastolic function as measured by IRT/ET was observed in the propranolol pretreatment group (Table). This was associated with significantly improved duration of survival and NDS (Table).
Conclusion: In a rat cardiac arrest model, propranolol pretreatment reduced the severity of post-resuscitation left ventricular dysfunction caused by epinephrine with improved NDS and duration of survival.
- © 2013 by American Heart Association, Inc.