Amiodarone for sustained stable ventricular tachycardia in the prehospital setting.

OBJECTIVE: Amiodarone is commonly used in the treatment of stable ventricular tachycardia (VT), but its efficacy has not been empirically examined in the prehospital setting. The objective of this study was to examine the safety and efficacy of amiodarone administered by paramedics to patients with stable VT.

METHODS: Patient records from Victoria, Australia between 1 May 2007 and 30 June 2017 were examined retrospectively. Patients attended by Ambulance Victoria with stable sustained VT who were administered amiodarone by paramedics as the initial treatment were included. Data were used to determine the prevalence of treatment with amiodarone, the incidence of VT termination prior to transfer of care, and the incidence of progression to electrical cardioversion.

RESULTS: Sixty-one patients were identified who met the inclusion criteria. The mean age was 72 years (standard deviation = 14) with 77% (n = 47) being male. Of the patients treated with amiodarone, 52% (n = 32) reverted successfully during paramedic care while 48% (n = 29) did not. Two patients required cardioversion for haemodynamic instability after amiodarone administration. One patient experienced cardiac arrest after receiving amiodarone and was successfully resuscitated by paramedics.

CONCLUSIONS: Approximately half of the patients treated with amiodarone reverted from VT while under paramedic care. Patient deterioration was rare, with cardiac arrest or requirement for cardioversion occurring very infrequently. Amiodarone was relatively safe and moderately effective for the treatment of sustained stable VT. However, given recent evidence of increased efficacy of procainamide for stable VT, further studies are required in the prehospital setting to compare these two drugs.