Effect of nifekalant for out-of–hospital cardiac arrest with shock-resistant ventricular fibrillation

Introduction

Nifekalant (NIF) is predominantly a Vaughan Williams Class III antiarrhythmic agent that is synthesized in Japan as a pure K channel blocker without a negative inotropic effect [1]. NIF has been the most effective antiarrhythmic drug recommended for patients with ventricular fibrillation (VF) resistant to some other antiarrhythmic drugs in Japan. However, whether NIF improves the rate of successful resuscitation after out-of-hospital cardiac arrest with shock-resistant VF has not been determined. Our preliminary study found a significant improvement in the proportion of patients surviving to the emergency department following out-of-hospital cardiac arrest in NIF-treated patients [2]. Our protocol is as follows: for out-of-hospital cardiac arrest patients with shock-resistant VF or pulseless VT (after three or more precordial shocks), epinephrine (1 mg bolus) and then NIF (0.3 mg/kg bolus followed by 0.4 mg/kg/hour infusion) are administered. We showed 31% of out-of-hospital cardiac arrest patients with shock-resistant VF could survive by treatment with this protocol [2]. We will show the details of the clinical course of successfully recovered patients treated with this protocol.

Case

A 70-year-old man with acute onset of chest pain developed VF within 2 hours of symptom onset when driving his car. He was initially treated by an ambulance team with basic life support measures, including the delivery of thre shocks. When the patient arrived at hospital, VF was prolonged. We provided advanced cardiac life support measures, and administered NIF according to our protocol and did more shocks, resulting in stabilization of VF. An angiography after return of spontaneous circulation showed an inferior acute myocardial infarction. The patient could be discharge with full recovery (cerebral performance category 1 [good cerebral performance]).

Conclusion

Nifekalant is a possibly effective antiarrhythmic agent for patients suffering from cardiac arrest with shock-resistant VF.