Abstract 328: Hemodynamic Comparison of Zucker Diabetic Fatty Rats to Their Lean Littermates After Asphyxial Cardiac Arrest

Abstract

Patients with metabolic syndrome are at higher risk for cardiac arrest (CA), and also have worse neurologic outcome after CA related to their comorbidities (e.g., Type 2 Diabetes Mellitus [T2DM]). Using Zucker Diabetic Fatty (ZDF) rats as a new and relevant model with common comorbidities for CA and cardiopulmonary resuscitation (CPR), we hypothesized that T2DM is associated with a lower chance for return of spontaneous circulation (ROSC) and/or a worse outcome regarding heart function after asphyxial CA compared to their lean littermates. Two groups of rats (8 ZDF, 7 lean) were monitored for 37±2 weeks. The rats were anesthetized and intubated; heart rate was monitored by subcutaneous ECG needles. Femoral artery and vein were cannulated for continuous blood pressure measurement and delivery of fluids and medications, respectively. Before ventilation was stopped to initiate asphyxial CA, rocuronium was given. After 8 minutes of CA, ventilation was re-initiated with FiO 2 1.0, epinephrine and sodium-bicarbonate were administered, and pneumatic chest compression were started with 200 compressions per minute. Chest compressions were stopped when a systolic blood pressure of 120 mmHg was achieved. During 4 hours of observation, vital parameters were closely monitored, blood gases were measured, and ejection fraction (EF %) was assessed with ultrasound. Data are mean ± SD. Statistics: Unpaired student’s t-test (two-tailed), α.05. At baseline, ZDF rats showed significantly higher blood glucose levels (504±52 vs 174±14 mg/dl) compared to their lean littermates. All ZDF and lean rats achieved ROSC, and measurements taken directly after ROSC and after the first hour showed no relevant differences. After four hours, there was no difference in heart rate between ZDF and lean rats. However, diabetic rats had a significantly higher mean arterial blood pressure (142±24vs. 107±19 mmHg) and ejection fraction (42±16%vs 20±8%) compared to their lean littermates. The hypothesis that ROSC-rate in diabetic rats would be lower could not be proven. Conversely, the ZDF rats showed a significantly higher blood pressure related to an increased EF%. Further analysis in this study will focus on the impact of T2DM on cardiac and neurological ischemia-reperfusion injury.