Abstract 2633: Post Treatment with Periodic Acceleration (pGz) after Cardiac Arrest Decreases Acute Post Resuscitation Myocardial Stunning in Swine
A motion platform was fabricated to produce periodic acceleration (pGz) by sinusoidal movement, head-foot movement of the supine body. In vivo and in vitro, pGz induces pulsatile shear stress on the vascular endothelium thereby releasing endothelial derived NO (eNO) and prostaglandins. pGz can serve as the sole means of CPR in a ventricular fibrillation (VF) swine model. Compared to standard chest compression-ventilation CPR, pGz-CPR decreases post resuscitation myocardial stunning and improves outcomes. eNO and prostaglandins have both been shown to be critical mediators during CPR and after ischemia reperfusion injury(I/R). Thus, pGz applied as post treatment shortly after CPR (POST) might ameliorate myocardial I/R. Eighteen male swine (40 –50lbs) were anesthetized, intubated and instrumented to measure arterial blood gases and hemodynamics. VF was electrically induced and unsupported for 8 min, followed by continuous manual chest compression and defibrillation until return of spontaneous circulation (ROSC) or 10 min. Then, swine were randomized to receive continuous pGz (motion at frequency of 3 Hz and Gz ± 0.4) (POST) for the remainder of the observation period or none, control(C). Echocardiograms to measure ejection fraction (EF%), fractional shortening ( FS%) and wall motion score index (WMSI) were performed at baseline (BL), 30 and 120 min after ROSC (ROSC30, ROSC120). All animals had ROSC after a median of 4 defibrillation attempts. There were no differences between groups in defibrillation attempts, time to ROSC, arterial blood gases or hemodynamics over time. Compared to C, POST animals had less acute myocardial stunning as evidenced by echo. Data mean ± SD, * p < 0.05 C vs POST , † p< 0.05 time vs BL Post treatment pGz applied shortly after ROSC decreases acute post resuscitation myocardial stunning. Application of pGz after I/R due to VF and CPR may be a simple non-invasive method for promoting cardioprotection.