How to manage bradycardia in a patient receiving Amiodarone IV?

Management of Amiodarone-Induced Bradycardia

When bradycardia (HR 55 bpm) occurs during IV amiodarone infusion, immediately slow or discontinue the infusion, as this is the primary recommended intervention for amiodarone-related bradycardia. 1

Immediate Actions

Primary Intervention

• Reduce the infusion rate or stop the amiodarone infusion entirely 1, 2
• Bradycardia occurs in 4.9% of patients receiving IV amiodarone and is not dose-related but appears related to infusion rate 1
• This intervention resolves bradycardia in most cases without requiring permanent discontinuation 1

Assessment of Clinical Stability

• Determine if the patient is symptomatic or hemodynamically unstable from the bradycardia 2
• Check blood pressure, as hypotension occurs in 16% of patients on IV amiodarone and may coexist with bradycardia 1
• Assess for signs of inadequate perfusion (altered mental status, chest pain, dyspnea, hypotension) 2

Risk Stratification

High-Risk Features Requiring Pacing Readiness

• Pre-existing conduction disorders carry 24% risk of symptomatic bradycardia 3
• Patients with first-degree AV block, bundle branch blocks, or sinus node dysfunction are at substantially increased risk 3
• Have temporary pacing immediately available for patients with known predisposition to bradycardia or AV block 1, 2

Contraindications to Continuing Amiodarone

• IV amiodarone should not be used in patients with bradycardia or heart block who do not have a pacemaker 1
• Second- or third-degree heart block without pacemaker is an absolute contraindication 1

Management Algorithm

If Bradycardia Persists After Slowing/Stopping Infusion:

1. Consider temporary pacing if bradycardia is symptomatic or progressive 1, 2
2. Despite interventions, bradycardia was progressive and terminal in 1 patient during controlled trials 1
3. Do not resume amiodarone at the same rate; if restarting is necessary, use a slower infusion rate 1, 2

Concomitant Medication Review:

• Check for other AV nodal blocking agents (beta-blockers, calcium channel blockers, digoxin) that may potentiate bradycardia 1
• Amiodarone inhibits metabolism of beta-blockers through CYP2D6 1
• Consider reducing or holding these medications temporarily 1

Common Pitfalls to Avoid

• Do not administer additional AV nodal blocking agents during acute bradycardia 1
• Do not assume bradycardia will resolve spontaneously while continuing the same infusion rate 1
• Do not overlook electrolyte abnormalities (hypokalemia, hypomagnesemia) that may exacerbate conduction disturbances 1, 2
• In patients with pre-existing conduction disorders (first-degree AV block, bundle branch blocks, sinus node dysfunction), the risk of symptomatic bradycardia is significantly elevated at 24% versus 0% in those without conduction abnormalities 3

Long-Term Considerations

• If amiodarone therapy must continue, transition to oral dosing allows for better titration and lower maintenance doses (200-400 mg daily) which reduces bradycardia risk 1
• Sinus bradycardia during oral maintenance therapy occurs in 11.2% of patients but usually improves with dose reduction 4
• Permanent pacemaker implantation may be required in patients who need continued amiodarone but develop persistent symptomatic bradycardia 1