Makindo Medical Notes

Related Subjects: |Atrial Flutter |Atrial Fibrillation |AF and Anticoagulation |AF and Rate Control |AF and Rhythm Control and Cardioversion |AF ECG |DC cardioversion |Wolff-Parkinson White syndrome (WPW) |Supraventricular Tachycardia (SVT) |Ventricular Tachycardia |Ventricular Fibrillation |Resuscitation - Adult Tachycardia Algorithm |Resuscitation - Advanced Life Support

⚡ Quick Guide

ℹ️ About

• ⚡ AF = chaotic atrial activation → loss of atrial contraction.
• 🧠 Major risk of cardioembolism → ischaemic stroke.
• 💊 Most patients require anticoagulation.

🧬 Aetiology

• Atrial fibrosis, increased automaticity, or multiple re-entry circuits.
• ⚡ Atrial rate: 400–600/min → ventricular response matters.
• ⛔ AV node limits rate (~200/min) unless accessory pathway (e.g., WPW) → risk of VF.

📈 ECG

🫀 Physiology

• ⏱️ High HR → shortened diastole → ↓ LV filling & coronary perfusion.
• ❤️ Impaired LV function or mitral stenosis worsens compromise.

🩺 Clinical Presentation

• May be 🤐 asymptomatic, or present with palpitations, dyspnoea, chest pain, fatigue, syncope, hypotension, irregular pulse, or stroke.

⚠️ Clinical Effects

• ↑ Mortality, stroke, HF admissions, ↓ quality of life, LV dysfunction.

🔎 Causes

• Ischaemic, valvular, hypertensive heart disease.
• Thyrotoxicosis, alcohol (“holiday heart”), sick sinus, PE, myocarditis, idiopathic.

📊 Types of AF

🪞 Valvular vs Non-Valvular

• 🫀 Valvular AF (e.g., mitral stenosis) → higher thromboembolism risk.
• 🧮 Non-Valvular AF → use CHA₂DS₂-VASc for stroke risk.

🔬 Investigations

• 🧪 Bloods: FBC, U&E, Mg, Ca, K, TFT, LFT, alcohol, iron studies.
• 📈 ECG: absent P-waves, fibrillatory baseline.
• 🩻 Echo: LV function, valve disease, LA size.
• 👁️ TOE: LA appendage thrombus.

🎯 Rate Control

• 🎛️ First-line in many (esp. older, minimal symptoms).
• Target: <110 bpm if asymptomatic; <80 bpm if symptomatic.
• 💊 Beta-blockers (bisoprolol, metoprolol).
• 💊 CCBs (diltiazem, verapamil) if β-blocker not tolerated.
• 💊 Digoxin (esp. with HF, often in combo).

🔄 Rhythm Control

• Useful in younger or symptomatic patients.
• 💊 Antiarrhythmics:
  • Class Ic (flecainide, propafenone) if no structural disease.
  • Class III (amiodarone, dronedarone, sotalol) if structural disease.
• ⚡ Electrical cardioversion (DCCV) under sedation.
• 🔥 Catheter ablation for refractory or recurrent cases.

🛡️ Anticoagulation

• Prevents stroke from LA appendage thrombus.
• 📊 Guided by CHA₂DS₂-VASc: ≥2 men, ≥3 women → anticoagulate.
• 💊 Warfarin (INR 2–3) or DOACs (apixaban, rivaroxaban, dabigatran, edoxaban).

🩹 Manage Underlying Conditions

• 📉 Control BP.
• ❤️ Treat HF.
• ⚖️ Weight management.
• 😴 Diagnose & treat OSA (CPAP).

🌱 Lifestyle

• 🏃 Moderate exercise (avoid excess high-intensity).
• 🍷 Limit alcohol.
• ☕ Avoid stimulants (caffeine, nicotine, drugs).
• 🚭 Smoking cessation.

👴 Special Considerations

• 👵 Elderly: rate control + anticoagulation often safest.
• 🔕 Asymptomatic AF → still stroke risk, may need anticoagulation.
• 🛠️ LA appendage occlusion (e.g., Watchman) if anticoagulation unsuitable.

🩺 Case 1 — Symptomatic Presentation

A 72-year-old man presents with palpitations, breathlessness, and reduced exercise tolerance. Pulse is irregularly irregular at 140 bpm, BP 110/70. ECG confirms atrial fibrillation with fast ventricular response. Management: ⚖️ Decide between rate control (beta-blocker, diltiazem, or digoxin in sedentary) vs rhythm control if new-onset and suitable. Anticoagulation guided by CHA₂DS₂-VASc. Avoid: ❌ Flecainide or other class IC antiarrhythmics if structural heart disease/ischemia. Avoid abrupt withdrawal of rate control agents.

🩺 Case 2 — Incidental Finding

A 65-year-old woman attends a routine hypertension review. She is asymptomatic, but her pulse is irregular at 80 bpm. ECG shows atrial fibrillation. Echocardiography is normal, and thyroid function is normal. Management: 📅 Focus on stroke prevention — anticoagulation if CHA₂DS₂-VASc ≥2. Rate control if needed; otherwise observation is reasonable. Avoid: ❌ Relying on aspirin monotherapy (ineffective for stroke prevention). Avoid unnecessary cardioversion in long-standing, asymptomatic AF as futile and fails or then recurs.

🩺 Case 3 — Acute Decompensation

An 80-year-old man with heart failure presents with acute pulmonary oedema, tachycardia (AF with ventricular rate 160 bpm), and hypotension. He is hypoxic and distressed. Management: 🚑 Urgent stabilisation with oxygen, IV diuretics, and rate control (e.g., cautious IV amiodarone or digoxin if very unstable). Consider urgent DC cardioversion if haemodynamically compromised. Anticoagulation as soon as safe. Avoid: ❌ Verapamil/diltiazem in acute decompensated heart failure (negative inotropes). Avoid delaying cardioversion if shock or severe hypotension.