Should I give Amiodarone?

Good posts start with good questions. Have an ER question? Send it here.

KEY

🔍- Deep Dive

📌- Clinical Application

🔸 - Weak Evidence

🔹 - Strong Evidence

📑 - Evidence summaries

✅ - Recommended treatment

⚠️ - Critical Information

This question comes up again and again in atrial fibrillation (AF) management.

Many ER residents instinctively call cardiology just to decide whether to start amiodarone.

Most of the time, you don’t need a cardiology call to make the first decision.

Let’s simplify this.

👉

Jump to what matters ⏬

Why do we care?

Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice.

AF is not a benign rhythm. It can cause

Heart failure

Tachycardia-induced cardiomyopathy

Atrial clot formation

Thromboembolism -Systemic embolization, ischemic stroke

1.5–2× increased mortality

First - Is this really AF? - Look at the ECG

*Image source: Life in the Fast Lane (LITFL)*

Two key things to look at

Rhythm :

Irregularly irregular rhythm

P waves

Absent P waves
Fibrillatory waves (may mimic P waves)
No isoelectric baseline

Usually narrow QRS (<120 ms) (unless BBB, pre-excitation, or aberrancy)

Is the Patient Optimised?

Before chasing rhythm or rate—resuscitate first.

(ACLS 2024)

Stabilise and optimise ABCs

Correct precipitants: Think PIRATES

P – Pulmonary embolism
I – Ischemia (ACS, myocardial injury)
R – Respiratory disease (COPD, pneumonia, hypoxia)
A – Atrial enlargement / atrial myxoma
T – Thyroid disease
E – Ethanol / Electrolyte imbalance
S – Sepsis, Stress, Surgery

Is the patient unstable?

Or a better question-

Is the tachycardia causing the instability?

🔍

Uncontrolled AF can:

Impair ventricular filling

Reduce cardiac output

Decrease coronary perfusion

Increase myocardial oxygen demand

Assess instability — Think CHAAS

C – Chest pain (ischemic)

H – Hypotension

A – Altered mental status

A – Acute heart failure

S – Signs of shock

Any one present = Unstable AF

⚠️

DC cardioversion will stabilize the patient only if the AF is causing the instability.

Its Unstable AF - what now?

What to do?

Immediate management : Synchronized DC cardioversion

⚠️

Unsynchronized cardioversion can precipitate VF

How to do?

Initial energy : 200 J biphasic

Escalate in case of shock failure

📑

Why start high?

A higher initial shock energy is more effective than a “start low and titrate up” approach

Higher first-shock success
Require fewer total shocks
Shorten the duration of anesthesia.

A randomized trial showed that maximum fixed-energy shocks were more effective than a low-escalating energy strategy for electrical cardioversion.

Low-energy monophasic shocks → more likely to provoke ventricular fibrillation.

Pad positioning: There is no single optimal position

📑

A meta-analysis of 10 RCTs showed no difference in sinus rhythm restoration when comparing anterior-posterior with antero-lateral electrode positioning.

EPIC Trial :Anterior-lateral electrode positioning was more effective than anterior-posterior electrode positioning for biphasic cardioversion of atrial fibrillation.

What to do after this?

Immediate administration of amiodarone (if possible) improves the rate of successful ECV .

Anticoagulation caution

⚠️

AF >48 hours or unknown duration in non-anticoagulated patients carries thromboembolic risk

Ask first: Is your patient hemodynamically unstable?

(ESC Guidelines 2024)

YES — Unstable AF

Immediate synchronized DC cardioversion

Do not delay cardioversion for anticoagulation status

Check OAC status as soon as feasible after cardioversion

Post-cardioversion anticoagulation

Start short-term OAC for all patients - (regardless of baseline stroke risk)

NO — Hemodynamically stable AF

If anticoagulated ≥ 3 weeks

Proceed with cardioversion

If NOT adequately anticoagulated

Initiate DOAC / VKA / LMWH / UFH

(Consider TEE-guided strategy if available)

After cardioversion

Start short-term OAC for all patients - (regardless of baseline stroke risk)

Shock-refractory AF

AF that remains incessant despite ~3 maximum-energy synchronized shocks

Optimising shock success

Improve pad–skin contact

Apply firm pad pressure

Reposition pads to alter shock vector

Consider antiarrhythmic drugs to reduce defibrillation threshold

Consider double synchronized cardioversion

📑

The benefit of double-sequence cardioversion remains uncertain and should be considered only after standard optimization steps.

Step 3: Stable AF — Now what?

Now that we’ve moved past electrical cardioversion, there are two paths:

1️⃣ Rate control

2️⃣ Rhythm control

📑

AFFIRM trial

No mortality benefit of rhythm control over rate control

No quality-of-life advantage with rhythm control

Stroke rates were similar, despite more sinus rhythm in the rhythm group

(Patients unable to tolerate AF were largely excluded)

RACE trial

Studied patients with mild–moderate heart failure

Rate control is not inferior to rhythm control for major outcomes

Recent guidelines (ESC and AHA) recommend rate control as the initial strategy in most patients with atrial fibrillation.

✅

Rate control target: Heart rate <100–110 bpm.

The real deciding question here is :

Is there decompensated heart failure?

If NO → Consider Rate control options

First-line

β-blockers -Metoprolol, Esmolol

Non-DHP CCB - Diltiazem, Verapamil

Contraindicated if EF < 40%

✅

Both β-blockers and non-DHP CCBs are effective for ventricular rate control

High-quality data suggest diltiazem may achieve faster and better rate control than metoprolol

Second-line

Digoxin

Use only if β-blockers and non-DHP CCBs are contraindicated or ineffective
Can be considered alone or in combination with other drugs.

If monotherapy fails

If symptoms persist and are thought to be due to poor ventricular rate control

consider combination therapy with any two of the following:

β-blocker

Non-DHP CCB

Digoxin

(As per NICE guidance)

⚠️

Use Non-DHP-CCBs only if EF >40%

Adjunct therapy: IV Magnesium

✅

Adding magnesium to standard rate-control therapy is reasonable to help achieve and maintain ventricular rate control in atrial fibrillation.

Improves AV nodal refractoriness

Enhances response to β-blockers and CCBs

Dose: 2–4.5 g IV

📑

LOMAGHI Trial

Intravenous Magnesium appears to have a synergistic effect when combined with other AV nodal blockers, resulting in improved rate control. Similar efficacy was observed with 4.5 g and 9 g of Magnesium, but the 9 g dose was associated with more side effects.

If YES → Amiodarone

150–300 mg IV over 1 hour

Then 10–50 mg/h infusion over 24 hours

⚠️

QRS > 200 ms : Think pre-excitation / WPW

DO NOT give AV nodal blockers

They may precipitate ventricular fibrillation

Consider : Synchronized DC cardioversion /Procainamide

(often not available in India)

Still considering Rhythm Control?

Most stable AF patients do not need rhythm control in the ED.

Why consider rhythm control?

Restoration of sinus rhythm can

Reduce symptoms
Improve LV function

Who can you offer rhythm control to?

AF onset < 24 hours

(ESC Guidelines 2024; Often difficult to prove in the ED)

Adequately anticoagulated for ≥ 3 weeks

⚠️

If not anticoagulated, start DOAC / VKA / LMWH / UFH before cardioversion if time allows

Pharmacologic rhythm control options

Amiodarone

Drug of choice in: HFrEF, LVH, CAD, Other structural heart disease
Expect conversion : Often 8–12 hours, not immediate

There are other options not available in India

Flecainide / Propafenone (IV) - Recommended for recent-onset AF
Vernakalant

⚠️

DO NOT offer pharmacologic cardioversion if QTc > 500 ms

For quick ED reference: Drug doses

Rate Control Drugs

β-blockers

Metoprolol

2.5–5 mg IV over 2 minutes

May repeat every 5 minutes

Maximum: 3 doses

Esmolol

500 μg/kg IV bolus over 1 minute

Then 50–300 μg/kg/min infusion

Non-DHP CCBs

Diltiazem

0.25 mg/kg IV over 2 minutes

Repeat 0.35 mg/kg if needed

Maintenance: 5–15 mg/h infusion

Verapamil

5–10 mg IV over ≥2 minutes

May repeat up to 2 doses

Maintenance: 5 mg/h infusion (max 20 mg/h)

Digoxin

0.25–0.5 mg IV loading dose

Then 0.25 mg IV every 6 hours

Maximum: 1.5 mg in 24 hours

Amiodarone

150–300 mg IV over 1 hour

Then 10–50 mg/h infusion over 24 hours

Magnesium

2–4.5 g IV over 20 minutes

Rhythm control Drugs

Amiodarone

300 mg IV over 30–60 min

Then 900–1200 mg IV over 24 h

What matters…

The questions you should ask before you decide on what to do with the AF

1️⃣ Is the patient Unstable?

Look for CHAAS

C – Chest pain (ischemic)

H – Hypotension

A – Altered mental status

A – Acute heart failure

S – Signs of shock

If your patient is unstable

Immediate management : Synchronized DC cardioversion

Initial energy : 200 J biphasic

Escalate the energy in case of shock failure

If NOT adequately anticoagulated : Initiate anti coagulation

Consider amiodarone infusion.

2️⃣ Is there decompensated heart failure?

If YES → Amiodarone

150–300 mg IV over 1 hour

Then 10–50 mg/h infusion over 24 hours

3️⃣Is the EF > 40% ?

If NO → β-blocker

If YES → Non DHP-CCB / β-blocker

If there are any Contraindications to BB/CCB → Digoxin

Adjunct → IV Magnessium

Want to Read More?

Joglar, José A., et al. "2023 ACC/AHA/ACCP/HRS guideline for the diagnosis and management of atrial fibrillation: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines." Journal of the American College of Cardiology 83.1 (2024): 109-279.

Van Gelder, Isabelle C., et al. "2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS) Developed by the task force for the management of atrial fibrillation of the European Society of Cardiology (ESC), with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Endorsed by the European Stroke Organisation (ESO)." European heart journal (2024): ehae176.

Senoo, Keitaro, Yee Cheng Lau, and Gregory YH Lip. "Updated NICE guideline: management of atrial fibrillation (2014)." Expert review of cardiovascular therapy 12.9 (2014): 1037-1040.