Purpose: The purpose of the experiment was to compare the effects of nifekalant and amiodarone on the return of spontaneous circulation (ROSC), survival, as well as on the hemodynamic parameters in a swine model of prolonged ventricular fibrillation (VF).
Methods: After 8 min of untreated VF, bolus doses of epinephrine (adrenaline) and either nifekalant, or amiodarone, or saline (n = 10 per group), were administered after randomization. Cardiopulmonary resuscitation (CPR) was commenced immediately after drug administration and defibrillation was attempted 2 min later. CPR was resumed for another 2 min after each defibrillation attempt and the same dose of adrenaline was given every 4th minute during CPR.
Results: Forty-eight hour survival was significantly higher with nifekalant compared to amiodarone (p < 0.001) and saline (p = 0.02), (9/10 vs. 0/10 vs. 3/10, respectively). Systolic aortic pressure, diastolic aortic pressure and coronary perfusion pressure were significantly higher with nifekalant during CPR and immediate post-resuscitation period (p < 0.05). The animals in the amiodarone group had a slower heart rate at the 1st and 45th min post-ROSC (p < 0.001 and p = 0.006, respectively). The number of electric shocks required for terminating VF, time to ROSC and adrenaline dose were significantly higher with amiodarone compared to nifekalant (p < 0.001).
Conclusions: Nifekalant showed a more favorable hemodynamic profile and improved survival compared to amiodarone and saline in this swine model.
Keywords: Amiodarone; Antiarrhythmic drug; Arrhythmia; Cardiac arrest; Cardiopulmonary resuscitation; Nifekalant.