Here is the **clean, clinically usable AF management algorithm**, written exactly the way you’ll use it in **cardiac anaesthesia / CTICU**.
This follows **ESC 2020**, **AHA 2023**, **NICE NG196 (2021 ACS & AF major updates)** and **EACTA/EACTS** post-cardiac-surgery guidelines.
I’m giving you the full **step-by-step algorithm**, from **recognition → immediate stabilization → categorisation → treatment → escalation**.
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# ❤️ **Atrial Fibrillation (AF) Management Algorithm
(Cardiac ICU & Anaesthesia Version)**
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# **STEP 1 — Confirm AF**
**ECG features:**
* **No P waves**
* **Irregularly irregular QRS**
* Variable R–R intervals
**Check for triggers:**
* Hypoxia
* Hypovolaemia
* Pain
* Electrolyte imbalance (K⁺, Mg²⁺)
* Infection
* Anaemia
* Inotropes (dobutamine, adrenaline)
* Post-CPB inflammation
* Tamponade / ischemia
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# **STEP 2 — Assess Stability (Most Important Step)**
## **A. Unstable AF (any of following)**
* Hypotension **MAP < 65**
* Shock / poor perfusion
* Acute pulmonary oedema
* Ischaemic chest pain
* Altered mental status
๐ **Immediate synchronized DC cardioversion**
* 120–150 J biphasic → escalate to 200 J
* Give **amiodarone bolus** after if recurrence
* Correct electrolytes urgently
## **B. Stable AF**
Proceed to **rate vs rhythm control**.
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# **STEP 3 — Define the Scenario**
## **1. NEW-ONSET AF (<48h)**
Common after cardiac surgery (20–40%).
## **2. AF >48h or unknown duration**
Stroke risk ↑
Avoid cardioversion unless anticoagulated (or TEE excludes clot).
## **3. Post-cardiac surgery AF**
Often transient → rhythm control preferred.
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# **STEP 4 — First Actions (Universal for all AF)**
### **A. Correct Reversible Causes (Very Important)**
* K⁺ to **4.5–5.0 mmol/L**
* Mg²⁺ to **1.0–1.2 mmol/L**
* PaO₂ > 10 kPa
* Treat pain, fever, sepsis
* Reduce/stop inotropes (esp. dobutamine)
* Fix hypovolaemia or overload
* Check echo if suspicion of tamponade or new LV dysfunction
### **B. Anticoagulation**
* **Post-cardiac surgery AF <48h:** anticoagulation NOT routinely mandatory immediately
* AF >48h or cardioversion planned → start heparin once bleeding risk acceptable
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# **STEP 5 — Decide: RATE or RHYTHM CONTROL**
## **Use this rule:**
### **If post-cardiac surgery → RHTYHM control preferred.**
(Because AF worsens CO due to loss of atrial kick and increases risk of HF.)
### **If chronic AF or minimal symptoms → RATE control acceptable.**
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# **STEP 6 — Management Pathway**
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# **A. RATE CONTROL (if chosen)**
### **1. First-Line (Stable patient):**
| Drug | Dose | Notes |
| ----------------------------- | ----------------------------------- | --------------------------------------- |
| **Beta-blocker** (Metoprolol) | 2.5–5 mg IV q5 min (max 15 mg) | Best first choice after cardiac surgery |
| **Esmolol infusion** | Load 500 mcg/kg → 50–200 mcg/kg/min | Very titratable |
### **2. If LV dysfunction present**
* Use **amiodarone** instead of beta-blocker if EF < 35%
* Digoxin is slow and not preferred post-op unless severe LV failure
### **3. Avoid calcium channel blockers** (diltiazem, verapamil) in:
* LV dysfunction
* Post-cardiac surgery with labile BP
**Target heart rate:**
* **<110/min** (lenient target)
* If symptomatic: aim <100/min
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# **B. RHYTHM CONTROL (Preferred in Post-Cardiac Surgery)**
### **Indications:**
* New-onset AF <48h
* Haemodynamic effect (loss of atrial kick)
* LV dysfunction
* Symptomatic
* Post-CABG or valve surgery
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## **1. Pharmacological Cardioversion**
### **Amiodarone (first-line in CTICU)**
* **Bolus:** 150 mg IV over 10–20 min
* Then **infusion:** 1 mg/min for 6h → 0.5 mg/min for 18h
* Evaluate for conversion in 6–12 hours
### If amiodarone contraindicated:
* **Ibutilide** (not commonly used in SL)
* **Flecainide** (only if no structural heart disease — NOT used post-cardiac surgery)
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## **2. Electrical Cardioversion**
Use if:
* Severe symptoms
* LV dysfunction
* AF persists after drugs
* Recurrent AF with rapid ventricular response
* Post-valve/CABG patients with low CO
**Protocol:**
* Biphasic 150–200 J
* Sedation/anaesthesia as appropriate
* Repeat 200 J if needed
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# **STEP 7 — POST-CONVERSION CARE**
### **A. Maintain Sinus Rhythm**
* Continue **amiodarone infusion** for 24 h
* Transition to oral:
* 200 mg TDS for 1 week
* Then BD for 1 week
* Then 200 mg OD maintenance (depending on cardiology advice)
### **B. Restart/Continue Beta-blockers**
* Main prevention strategy after CABG
* Metoprolol 25–50 mg BD orally once stable
### **C. Correct and maintain electrolytes**
* K⁺ 4.5–5.0
* Mg²⁺ >1.0
### **D. Anticoagulation decisions**
* AF <48h post-op usually **does NOT need anticoagulation immediately**
* AF >48h → start **heparin**, transition to DOAC/warfarin once bleeding is minimal
* High-risk: CHA₂DS₂-VASc ≥2 → anticoagulate unless bleeding risk prohibitive
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# **STEP 8 — When to Escalate / Re-evaluate**
* Persistent AF >24–48 h despite treatment
* Severe LV/RV dysfunction
* Recurrent AF causing hypotension
* Suspected graft failure, tamponade, or perioperative MI
* Large pericardial effusion
* Rapid AF on inotropes (especially dobutamine)
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# **AF MANAGEMENT — COMPLETE ALGORITHM (Condensed)**
### **1. Diagnose AF → ECG confirm.**
### **2. Assess stability.**
* **Unstable → Immediate DC shock**
* **Stable → proceed**
### **3. Correct causes (K⁺, Mg²⁺, hypoxia, pain, fluid status).**
### **4. Decide: RATE vs RHYTHM CONTROL.**
* **Post-cardiac surgery → RHYTHM preferred.**
### **5. Rate control path:**
* Metoprolol → esmolol → amiodarone (if LV dysfunction)
### **6. Rhythm control path:**
* Amiodarone → wait 6–12h
* If fails → **DC cardioversion**
### **7. After conversion:**
* Continue amiodarone infusion → oral
* Restart beta-blockers
* Maintain electrolytes
* Anticoagulate only if duration >48h or high stroke risk
### **8. Escalate if:**
* AF persist >48h
* Haemodynamic compromise
* Recurrent AF
* Suspected surgical complication
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## ✅ **Key Post-Cardiac Surgery Pearls**
1. **Beta-blockers + electrolytes** = best prevention.
2. **Amiodarone** = first-line for rhythm restoration.
3. **Unstable AF → immediate DC cardioversion.**
4. **Always correct potassium & magnesium FIRST** before escalating therapy.
5. **Avoid diltiazem/verapamil** in low EF / post-cardiac surgery.
6. **Loss of atrial kick drops CO by 20–30%**, especially in LVH or severe AS — so rhythm control is vital.
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If you want, I can now create:
### **๐ธ A visually simple “AF Management Flowchart (Cardiac ICU Version)”
๐ธ A drug dosing card for AF management
๐ธ AF management pocket card for ward/OT**
Tell me which one you want.
