Efficacy and safety of short intravenous amiodarone in supraventricular tachyarrhythmias (original) (raw)

Efficacy and safety of intravenous amiodarone in acute refractory arrhythmias

Clinical Cardiology, 1988

Few data are available on intravenous amiodarone therapy in refractory arrhythmias. This retrospective study in 50 patients (14 with supraventricular and 36 with ventricular tachyarrhythmias) revealed a favorable effect of intravenous amiodarone in the treatment of life-threatening arrhythmias with an overall success rate of 76%. In the subgroup of patients with ventricular fibdlation and concomitant severe congestive heart failure success rate was low (25%, 2/8), whereas effectiveness in patients with ventricular tachycardias was high (> 90%) and proved to be independent of left ventricular function. If patients with recurrent ventricular fibrillation were excluded from the analysis, successful treatment with intravenous amiodarone was achieved in 90%, even in those patients with severely compromised myocardium.

A Low Incidence of Proarrhythmia Using Low-Dose Amiodarone

Journal of Electrophysiology, 1988

KERIN NZ, ET AL: LOW incidence of proarrhythmia using low-dose amiodarone. The incidence of proarrhythmia with antiarrhythmic agents is reported to be 2%-23%, depending on the agent, definition of proarrhythmia, method of assessment, and severity of underlying rhythm disturbance. Several case reports of amiodarone-induced proarrhythmia have appeared; however, its prevalence and clinical significance have not been adequately defined. In our series of 107 patients with potentially lethal ventricular arrhythmias, amiodarone was administered as a 5-mg/kg bolus infusion, followed by 600-800 mg/day for 7-10 days. A mean daily maintenance dose of 270 mg/day was given for an average of 15 months (range <57). Proarrhythmia was defined by the method ofMorganroth as: (1) a three-to tenfold increase in VPC frequency, (2) a marked increase in VT rate, or (3) the development of new sustained VT/VF or torsade de pointes. Bradyarrhythmias, conduction delays, and out-of-hospital sudden death were not included by definition. Baseline 24-hour-Holter monitoring revealed 449 ± 685 VPCs/hr, 740 ± 584 couplets/24 hr, and 61 + 685 episodes of nonsustained VT/24 hr. Proarrhythmia occurred in three patients (2.8%). Two of these episodes occurred during the first week of treatment and resolved without dosage adjustment. These episodes included a 4.7-and 5.1-fold increase in VPC frequency. The other proarrhythmic event was a case of torsade de pointes that occurred after 12 months of treatment and required acute intervention and withdrawal of amiodarone. In conclusion, lowdose amiodarone appears to have a low potential for proarrhythmia and compares favorably with other agents in this regard, perhaps owing to its unique electrophysioiogic properties.