From the FDA Drug Label
14 CLINICALSTUDIES Apart from studies in patients with VT or VF, described below, there are two other studies of amiodarone showing an antiarrhythmic effect before significant levels of DEA could have accumulated A placebo-controlled study of intravenous amiodarone (300 mg over 2 hours followed by 1200 mg/day) in post-coronary artery bypass graft patients with supraventricular and 2- to 3-consecutive-beat ventricular arrhythmias showed a reduction in arrhythmias from 12 hours on
- Amiodarone (IV) can be used as an antiarrhythmic for supraventricular arrhythmias, including pre-excited SVT.
- The studies show a reduction in arrhythmias with amiodarone therapy, but do not specifically address pre-excited SVT.
- However, based on the available data, amiodarone (IV) may be considered for the treatment of pre-excited SVT, given its effectiveness in reducing supraventricular arrhythmias 1.
From the Research
For pre-excited SVT, the recommended antiarrhythmic medications include procainamide, ibutilide, or amiodarone, with catheter ablation being the definitive treatment for recurrent episodes, as supported by the most recent study 2.
Key Considerations
- Procainamide can be administered at 15-17 mg/kg IV over 25-30 minutes.
- Ibutilide is dosed at 1 mg IV over 10 minutes (0.01 mg/kg for patients <60 kg).
- Amiodarone is given as 150 mg IV over 10 minutes, followed by an infusion of 1 mg/min for 6 hours, then 0.5 mg/min maintenance.
Important Avoidances
- AV nodal blocking agents such as adenosine, beta-blockers, calcium channel blockers, and digoxin should be avoided as they can paradoxically accelerate conduction through the accessory pathway, potentially precipitating ventricular fibrillation, as noted in 3 and 4.
Long-term Management
- Oral options include flecainide, propafenone, or amiodarone.
- Catheter ablation has a high success rate and is recommended as the first-line method for long-term management of recurrent, symptomatic paroxysmal SVT, including Wolff-Parkinson-White syndrome, as stated in 3 and 2.
Rationale
These medications work by directly affecting the accessory pathway, slowing conduction and increasing refractoriness, which helps terminate the arrhythmia and prevent recurrence, as discussed in 5 and 6. The choice of treatment should prioritize minimizing morbidity, mortality, and improving quality of life, with catheter ablation offering a definitive solution for recurrent episodes, as supported by the latest evidence 2.