Should amiodarone (Amio) drip be continued in a hospitalized patient with acute atrial fibrillation (AFib) with rapid ventricular response (RVR) who converted to normal sinus rhythm (NSR) and then reverted back to RVR after discontinuation of the drip?

Management of Amiodarone Drip in Acute Atrial Fibrillation with RVR

Yes, the amiodarone drip should be continued in this hospitalized patient with acute atrial fibrillation and RVR who has demonstrated a pattern of reverting to RVR when the drip is discontinued. 1, 2

Rationale for Continuing Amiodarone Infusion

The decision to continue the amiodarone drip is based on several key factors:

1. Pattern of Recurrence: The patient has already demonstrated that discontinuation of amiodarone leads to recurrence of RVR, which was successfully controlled again when the drip was restarted 1

2. Guideline Support: The AHA/ACC/HRS guidelines specifically state that "IV amiodarone can be useful to control heart rate with AF when other measures are unsuccessful or contraindicated" (Class IIa recommendation) 1

3. Acute Management Protocol: For acute management of AF with RVR, IV amiodarone is recommended to control heart rate when other measures fail 1

Duration of Continued Infusion

Based on the FDA-approved administration guidelines for IV amiodarone:

• Continue the maintenance infusion at 0.5 mg/min (720 mg per 24 hours) 3
• This maintenance infusion can be safely continued for 2-3 weeks regardless of the patient's age, renal function, or left ventricular function 3
• Use a concentration of 1-2 mg/mL for peripheral IV access or up to 6 mg/mL if using a central venous catheter 3

Monitoring Requirements

While continuing the amiodarone drip, the following monitoring is essential:

• Continuous ECG monitoring for QT prolongation, bradycardia, and heart block 2
• Regular vital sign checks with particular attention to hypotension 2
• Daily laboratory monitoring including electrolytes and liver function tests 2

Transition Plan

After stabilization (24-48 hours of maintained NSR), consider:

1. Transition to oral amiodarone based on duration of IV therapy 2:

   • If IV use <1 week: 800-1600 mg daily
   • If IV use 1-3 weeks: 600-800 mg daily
   • If IV use >3 weeks: 400 mg daily

2. Alternative rhythm control strategies if the patient cannot tolerate long-term amiodarone therapy

Cautions and Contraindications

Be vigilant for:

• Hypotension, especially in patients with compromised cardiac function
• QT prolongation and risk of torsades de pointes
• Bradyarrhythmias or AV blocks
• Do not exceed concentrations of 2 mg/mL in peripheral lines to avoid phlebitis 3

Clinical Pearls

• Amiodarone has been shown to be superior to other antiarrhythmics in maintaining sinus rhythm after cardioversion, with 62% of patients remaining in sinus rhythm at 1 year compared to 23% with class I agents 2
• For patients who have demonstrated recurrence of AF with RVR after discontinuation of amiodarone, maintaining the infusion is reasonable to prevent further episodes that could lead to hemodynamic compromise 1, 4
• Research has shown that intravenous amiodarone can exert additional electrophysiological effects even in patients already on chronic oral amiodarone therapy 4

The pattern of recurrence upon discontinuation strongly suggests the need for continued therapy until a more definitive treatment plan can be established.