Abstract 137: Ranolazine Increases Amplitude Spectrum Area During Untreated Ventricular Fibrillation and Cardiopulmonary Resuscitation
Background: Amplitude spectrum area (AMSA) has been demonstrated to be related to myocardial vitality during ventricular fibrillation (VF). Deregulation of intracellular Ca2+ homeostasis plays a critical role in the pathophysiology of the myocardial ischemia/reperfusion injury after cardiac arrest and CPR and therefore compromises the resuscitation outcome. We investigated the effects of ranolazine (ran) on AMSA during VF and CPR in a rat model of cardiac arrest and CPR. We hypothesized that ran, by reducing post resuscitation intracellular Ca2+ overload, would increase myocardial vitality and thereby AMSA during VF and CPR, ameliorating resuscitation outcome and survival.
Methods: Eighteen SD rats (520±45 g) were randomized to receive intravenously ran, 10 mg/kg (n=11), or vehicle (n=7). Fifteen mins later, VF was induced and untreated for 8 min. CPR, including mechanical chest compression and ventilations, was performed for 8 min prior to defibrillation. ECG, arterial and right atrial pressures were monitored and AMSA was calculated by fast Fourier transform. Myocardial dysfunction was echocardiographically assessed.
Results: Ran treated rats presented a significantly higher AMSA during untreated VF compared to vehicle treated ones (p<0.01). During CPR, AMSA increased continuously in ran animals. AMSA remained significantly higher in ran animals compared to controls(p<0.05). All the animals treated with ran were successfully resuscitated and survived for 72 hr, while 8 of the 11 vehicle treated ones were resuscitated and only 6 survived up to 72 hr. Rats receiving ran presented also a better ejection fraction 72 hr post resuscitation compared to those that received vehicle (82±1 vs. 75±2, p<0.05).
Conclusions: Administration of ran increased AMSA during VF and CPR. This led to a better resuscitation outcome and survival with improved myocardial function.
- © 2013 by American Heart Association, Inc.