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A Low Incidence of Proarrhythmia Using Low‐Dose Amiodarone
Author(s) -
KERIN NICHOLAS Z.,
BLEVINS ROGER D.,
KERNER NATHAN,
FAITEL KATHY,
FRUMIN HOWARD,
MACIEJKO JAMES J.,
RUBENFIRE MELVYN
Publication year - 1988
Publication title -
journal of electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 0892-1059
DOI - 10.1111/j.1540-8167.1988.tb01490.x
Subject(s) - proarrhythmia , amiodarone , medicine , anesthesia , cardiology , bolus (digestion) , antiarrhythmic agent , qt interval , heart disease , atrial fibrillation
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 of Morganroth 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, low‐dose amiodarone appears to have a low potential for proarrhythmia and compares favorably with other agents in this regard, perhaps owing to its unique electrophysiologic properties.