Atrial Fibrillation Nursing Guide

What is Atrial Fibrillation?

AF is the most common sustained cardiac arrhythmia, characterised by chaotic atrial electrical activity causing irregular, often rapid ventricular response. It affects 1–2% of the general population and increases stroke risk 5-fold.

AF Classification

Type	Duration	Notes
Paroxysmal	Episodes <7 days; self-terminating	May recur; treat each episode
Persistent	>7 days OR requires cardioversion	Sustained but not permanent
Long-standing persistent	Continuous >12 months	Rhythm control attempted
Permanent	Accepted as ongoing; cardioversion abandoned	Rate control strategy only
Lone AF	No structural heart disease, <60 years	Lower thromboembolic risk

ECG Features of AF

Absent P waves — replaced by fibrillatory (f) waves at 350–600/min (irregular baseline)
Irregularly irregular RR intervals — hallmark finding; no pattern to ventricular response
Ventricular rate: Typically 100–160 bpm if uncontrolled; normal QRS morphology (unless aberrant conduction)
QRS: Usually narrow; wide QRS if bundle branch block or pre-excitation (WPW)

Distinguish from: Atrial flutter (regular sawtooth P waves at 300/min, regular 2:1 or 3:1 block) and SVT (regular narrow tachycardia with P waves).

Causes of AF (PIRATES Mnemonic)

Letter	Cause
P	Pulmonary disease (PE, COPD, pneumonia)
I	Ischaemia (MI, coronary artery disease)
R	Rheumatic heart disease (mitral stenosis)
A	Anaemia, Atrial enlargement
T	Thyrotoxicosis (hyperthyroidism)
E	Electrolyte disorders (hypokalaemia, hypomagnesaemia), Ethanol
S	Sepsis, Sleep apnoea, Surgery (post-cardiac)

CHA₂DS₂-VASc Score — Stroke Risk

Factor	Points
C — Congestive heart failure / LV dysfunction	1
H — Hypertension	1
A₂ — Age ≥75 years	2
D — Diabetes mellitus	1
S₂ — Stroke / TIA / thromboembolism history	2
V — Vascular disease (prior MI, PAD, aortic plaque)	1
A — Age 65–74 years	1
Sc — Sex category: Female	1

Anticoagulation Decision

Score (Male)	Score (Female)	Annual Stroke Risk	Recommendation
0	0–1	~0%	No anticoagulation
1	2	~1.3%	Consider anticoagulation
≥2	≥3	>2%	Anticoagulation recommended

Female sex alone (score = 1 in female) does NOT mandate anticoagulation if no other risk factors. Must have at least one additional clinical risk factor.

🧮 CHA₂DS₂-VASc Calculator

Sex

Age

Congestive Heart Failure?

Hypertension?

Diabetes mellitus?

Prior stroke/TIA?

Vascular disease (MI, PAD, aortic plaque)?

HAS-BLED — Bleeding Risk

Assess bleeding risk BEFORE starting anticoagulation. High HAS-BLED score (≥3) does NOT automatically contraindicate anticoagulation — it prompts correction of reversible risk factors (uncontrolled hypertension, excess alcohol, interacting drugs).

Factor	Points
Hypertension (SBP >160)	1
Abnormal renal/liver function	1 each
Stroke history	1
Bleeding history or predisposition	1
Labile INR (if on warfarin)	1
Elderly (>65)	1
Drugs (antiplatelets, NSAIDs) or Alcohol	1 each

Rate vs Rhythm Control

Rate Control

Target resting HR <110 bpm (lenient) or <80 bpm (strict, if symptomatic). Preferred approach for permanent AF and most patients.

Drug	Dose (Oral)	Notes
Metoprolol/bisoprolol (beta-blocker)	Metoprolol 25–100 mg BD; bisoprolol 2.5–10 mg OD	First line; avoid in asthma/decompensated HF
Diltiazem/verapamil (non-DHP CCB)	Diltiazem 60–120 mg TDS	Avoid in HFrEF; useful if beta-blocker intolerant
Digoxin	0.125–0.25 mg OD	Poor rate control during exercise; useful in sedentary elderly or HF patients; narrow therapeutic index — monitor levels
Amiodarone	200 mg TDS × 1 week, then 200 mg BD, then 200 mg OD	Reserve for refractory cases; significant side effects (thyroid, pulmonary, liver, photosensitivity)

Rhythm Control — Cardioversion

Anticoagulation before cardioversion: If AF duration >48 hours (or unknown) → therapeutic anticoagulation for ≥3 weeks before cardioversion AND ≥4 weeks after. If <48 hrs → immediate cardioversion with UFH/LMWH coverage is acceptable.

Electrical cardioversion (DC): Synchronised DCCV 120–200 J biphasic. Patient sedated (procedural sedation). High success rate (80–90%) but 50% recurrence at 1 year.

Chemical cardioversion:

Flecainide (pill-in-pocket) — for paroxysmal AF without structural heart disease; 200–300 mg single oral dose
Amiodarone IV — for AF with structural heart disease or haemodynamic compromise
Vernakalant IV — newer agent for rapid chemical cardioversion

New-Onset AF — Emergency Management

If haemodynamically UNSTABLE (SBP <90, chest pain, syncope) → emergency synchronised DCCV immediately
If haemodynamically stable → rate control first (metoprolol IV or digoxin IV)
Treat precipitating cause: thyroid function, electrolytes, infection, PE
Anticoagulate: heparin infusion or LMWH if planning cardioversion

Anticoagulation in AF

Anticoagulant Comparison

Drug	Mechanism	Monitoring	Reversal Agent	Notes
Warfarin	Vitamin K antagonist	INR 2–3 (target)	Vitamin K; 4-factor PCC	Frequent monitoring; multiple interactions; preferred in severe renal failure, prosthetic valves, mitral stenosis
Rivaroxaban	Direct factor Xa inhibitor	None routinely	Andexanet alfa	20 mg OD with evening meal; avoid CrCl <15; preferred by many GCC patients
Apixaban	Direct factor Xa inhibitor	None routinely	Andexanet alfa	5 mg BD (2.5 mg BD if ≥2 of: age ≥80, weight ≤60kg, creatinine ≥133); lower bleeding than warfarin
Dabigatran	Direct thrombin inhibitor	None routinely	Idarucizumab	150 mg BD; 110 mg BD if age ≥80, high bleed risk; avoid CrCl <30
Edoxaban	Direct factor Xa inhibitor	None routinely	Andexanet alfa	60 mg OD; 30 mg if CrCl 15–50, weight ≤60kg, certain P-gp inhibitors

Warfarin mandatory in: Mechanical heart valves, mitral stenosis with AF, severe renal failure (CrCl <15). DOACs are contraindicated in these settings.

GCC-Specific Context

AF in the GCC

Rheumatic heart disease: Still prevalent in GCC expatriate workers from endemic regions (South Asia, Africa) — rheumatic mitral stenosis + AF requires warfarin (DOACs inadequate)
Thyrotoxicosis: Higher iodine deficiency history in some GCC populations; hyperthyroid AF resolves with thyroid treatment
Ramadan fasting: Digoxin and warfarin dosing schedules require Ramadan-specific guidance from pharmacist; INR monitoring gaps occur during fasting month
Warfarin interactions: Traditional herbal medicines (especially fenugreek, which is common in GCC cooking) can enhance warfarin effect — counsel patients on dietary consistency
Heat dehydration: Electrolyte imbalances (hypokalaemia) from excessive sweating precipitate AF in summer months

Exam Tips

CHA₂DS₂-VASc score calculation — always tested; female sex alone = 1 point but doesn't mandate anticoagulation
Warfarin mandatory for mechanical valves and mitral stenosis — DOACs contraindicated
Cardioversion rule: >48 hrs AF → anticoagulate 3 weeks before + 4 weeks after
Flecainide pill-in-pocket: only in structurally normal hearts
ECG: irregularly irregular, absent P waves, fibrillatory baseline
Digoxin — narrow therapeutic index; not for rate control during exercise

Exam MCQs — DHA / SCFHS / QCHP

Q1. A 68-year-old male with AF has hypertension and type 2 diabetes. His CHA₂DS₂-VASc score is 3. What is the recommended management?

A) Aspirin 75 mg daily — adequate for stroke prevention in AF B) No anticoagulation — score not high enough C) Oral anticoagulation — warfarin or DOAC D) Anticoagulation only if patient develops stroke symptoms

✅ C — CHA₂DS₂-VASc ≥2 in males recommends oral anticoagulation. Aspirin is NOT recommended for stroke prevention in AF — it provides minimal benefit but similar bleeding risk. DOACs are preferred over warfarin in non-valvular AF.

Q2. A patient with AF and a mechanical mitral valve replacement requires anticoagulation. Which agent is CORRECT?

A) Rivaroxaban 20 mg OD B) Apixaban 5 mg BD C) Warfarin — INR target 2.5–3.5 D) Dabigatran 150 mg BD

✅ C — Mechanical heart valves are a mandatory indication for warfarin. All DOACs are contraindicated with mechanical heart valves. The RE-ALIGN trial showed dabigatran was inferior and caused more thromboembolic and bleeding events vs warfarin in mechanical valve patients.

Q3. A patient is scheduled for elective DC cardioversion. AF onset was documented 5 days ago. What must happen BEFORE cardioversion?

A) Therapeutic anticoagulation for at least 3 weeks before cardioversion B) Cardioversion can proceed immediately with heparin cover C) Aspirin loading for 48 hours before cardioversion D) No anticoagulation needed for elective cardioversion

✅ A — AF duration >48 hours → must anticoagulate therapeutically for ≥3 weeks before cardioversion (left atrial thrombus may have formed). Alternatively, TOE to exclude thrombus then cardioversion with heparin cover. Continue anticoagulation ≥4 weeks post-cardioversion.

Q4. A nurse monitoring a patient on digoxin for rate control of AF notes the patient is bradycardic (HR 48) and complaining of nausea and visual disturbances with yellow-green halos. What is the PRIORITY action?

A) Administer the next digoxin dose as scheduled B) Hold digoxin, check serum digoxin level and electrolytes, notify medical team C) Administer atropine 0.5 mg IV for bradycardia D) Increase digoxin dose to improve rate control

✅ B — Classic signs of digoxin toxicity: bradycardia, nausea/vomiting, xanthopsia (yellow-green visual halos), confusion. Hold digoxin immediately. Check serum level (>2 ng/mL = toxic) and potassium (hypokalaemia worsens toxicity). Do NOT administer atropine without medical review.

❤️ Atrial Fibrillation (AF)