Atrial flutter 💓 ✅

Related Subjects: |Wolff-Parkinson White syndrome (WPW) AVRT |Lown Ganong Levine Syndrome AVRT |Supraventricular Tachycardia (SVT) |Atrioventricular Nodal Reentrant Tachycardia AVNRT |Atrial Flutter |Atrial Fibrillation |Sinus Tachycardia |Sinus Arrhythmia |Multifocal Atrial Tachycardia |Resuscitation - Adult Tachycardia Algorithm |AF and Anticoagulation

⚠️ Important: Class I antiarrhythmics (e.g. flecainide) must be used with AV nodal blockade (β-blocker or rate-limiting calcium channel blocker) to prevent dangerous 1:1 AV conduction ⚡. ❌ Avoid antiarrhythmic monotherapy in atrial flutter. 🔥 Catheter ablation (targeting the re-entrant circuit) has >90% success and is first-line definitive therapy in typical flutter.

ℹ️ About Atrial Flutter

• ⚡ Atrial rate: 280–350 bpm due to a macro-reentrant circuit.
• 🧐 Ventricular rate typically ~150 bpm with 2:1 AV block.
• 🔄 Often alternates with atrial fibrillation (AF–flutter spectrum).
• 💓 Usually originates in the right atrium (cavotricuspid isthmus-dependent circuit).

🧬 Aetiology

• 🔁 Macro-reentrant arrhythmia (classically cavotricuspid isthmus dependent).
• ❤️ Structural heart disease: IHD, hypertension, valvular disease, cardiomyopathy.
• 🌬️ Systemic triggers: COPD, hyperthyroidism, infection, alcohol (“holiday heart” 🍷).
• 🛠️ Post-cardiac surgery or prior ablation → atypical flutter.

📊 Types of Atrial Flutter

📈 ECG Findings

• 🪚 Sawtooth flutter waves, best seen in leads II, III, aVF.
• ⚡ 2:1 AV conduction → ventricular rate ~150 bpm (common).
• 🚨 1:1 conduction → ventricular rate 250–300 bpm (life-threatening).
• 💉 Adenosine or vagal manoeuvres may unmask flutter waves.

🤒 Clinical Presentation

• 💓 Palpitations, fatigue, dyspnoea, dizziness.
• 🧘 May be asymptomatic if rate controlled.
• 🚨 Severe cases: hypotension, syncope, acute heart failure.

🔬 Investigations

• 🧪 Bloods: FBC, U&E, Mg²⁺, TFTs, CRP, troponin.
• 📈 ECG: diagnostic (flutter waves + conduction pattern).
• 🩻 Echocardiography: assess LV function, atrial size, valvular disease.
• 📟 Holter monitor: paroxysmal detection.
• 💉 Adenosine: diagnostic (transient AV block reveals flutter waves).

⚡ Acute Management (NICE NG196)

• 🚨 Haemodynamically unstable: Immediate synchronized DC cardioversion.
• 🧘 Stable: Rate control first-line (β-blocker or rate-limiting CCB).
• ⏱️ Consider early cardioversion if onset <48h or patient anticoagulated.

🎛️ Rate Control

• β-blockers (e.g. bisoprolol) 👍
• Rate-limiting CCBs (diltiazem/verapamil) 👍
• Digoxin useful in sedentary patients or heart failure ⚠️ (less effective in exertion)

🔄 Rhythm Control

• ⚡ Electrical cardioversion – rapid and effective.
• 💊 Flecainide (ONLY if no structural heart disease) + AV nodal blocker.
• 💊 Amiodarone reserved for structural heart disease or refractory cases.

🔥 Catheter Ablation

• 🎯 First-line definitive therapy for typical atrial flutter.
• 📈 Success rate >90%; low recurrence.
• Reduces need for long-term antiarrhythmic drugs.

🛡️ Anticoagulation (NICE NG196)

• 📊 Use CHA₂DS₂-VASc score (same as AF).
• 💊 DOACs first-line (apixaban, rivaroxaban, dabigatran, edoxaban).
• ⚖️ Warfarin if mechanical valve or moderate–severe mitral stenosis.
• ❌ Do NOT use aspirin monotherapy for stroke prevention.

🚫 Contraindications / Caution

• ❌ Flecainide in structural heart disease or IHD.
• ❌ Non-DHP CCBs in decompensated systolic heart failure.
• ⚠️ Excess β-blockade → bradycardia, hypotension.
• ⚠️ Antiarrhythmics without AV nodal blockade → risk of 1:1 conduction ⚡

📊 Rate vs Rhythm Control

🩺 Case-Based Learning

• Case 1: 66M, HR 150 → typical flutter. → β-blocker → consider cardioversion → ablation. 🧠
• Case 2: 78F, HF + flutter. → Digoxin + diuretics → anticoagulate → consider ablation. ❤️
• Case 3: 70M, HR 280, hypotensive. → 🚨 Immediate DC cardioversion. ⚡

🌱 Lifestyle & Risk Factor Management

• 🚭 Smoking cessation
• 🍷 Reduce alcohol intake
• ⚖️ Weight optimisation
• 💊 Treat HTN, thyroid disease, COPD

📚 References

• NICE NG196 – Atrial Fibrillation & Flutter
• ESC Guidelines on Atrial Arrhythmias
• Stroke Association UK