Atrial Fibrillation/Flutter

Question 1

Define atrial fibrillation

Answer 1

supraventricular tachycardia – uncoordinated atrial contraction -> irregularly irregular ventricular response

Question 2

Define atrial flutter

Answer 2

supraventricular tachycardia with atrial rate ~300bpm with AVN conducting every 2nd beat -> ventricular rate of ~150bpm
Saw-toothed flutter waves on ECG

Question 3

What are the causes of atrial fibrillation?

Answer 3

Systemic
• Advancing age
• Infection/sepsis
• Diabetes
• Hyperthyroidism
• Hypertension
• Alcohol
• Electrolyte imbalance

Heart
• Ischaemic heart disease e.g. MI, CAD
• Hypertensive heart disease
• Heart failure
• Valvular heart disease
• Cardiomyopathies
• Pericarditis
• Myocarditis

Lung
• Bronchial carcinoma
• Pulmonary embolism
• Pneumonia

Question 4

What are the causes of atrial flutter?

Answer 4

Systemic
• Advancing age
• Hyperthyroidism

Heart
• Surgical/post-ablation scarring of atria
• Valvular heart disease -> atrial dilation
• Atrial septal defects
• Heart failure

Lung
• COPD
• Asthma
• Pneumonia

Question 5

What are the symptoms of atrial fibrillation/flutter?

Answer 5

• Asymptomatic
• Palpitations
• Dizziness
• Syncope
• SOB
• Chest pain

Question 6

What are the signs of atrial fibrillation/flutter?

Answer 6

• Irregular pulse

* Hypotension

Question 7

What are the investigations for atrial fibrillation/flutter?

Answer 7

ECG: 
- Atrial fibrillation
▪ Absent p waves
▪ Fibrillatory waves
▪ Irregularly irregular QRS complexes
- Atrial flutter
▪ Saw-toothed flutter waves
▪ 2:1 AV block (300bpm:150bpm)
• 24hr holter
• Exercise ECG – exclude IHD
• Bloods
   > U&Es (K, Mg) – exclude electrolyte imbalances
• Cardiac biomarkers – exclude MI/ischaemia
   > Elevated CK-MB
   > Elevated troponin
• TFTs – exclude hyperthyroidism
• CXR – exclude heart failure, pneumonia
• TTE/TOE – exclude heart failure, valvular heart disease

Question 8

What is the management for atrial fibrillation/flutter?

Answer 8

Treat the underlying cause!

Acute haemodynamically unstable
• DC cardioversion

Acute haemodynamically stable: 
Rate control
• Beta-blocker
• Digoxin
• Rate-limiting CCBs e.g. verapamil
Rhythm control (cardioversion)
• If onset >48h anticoagulate for 3-4 weeks before cardioversion
• Mechanical cardioversion: DC cardioversion
• Chemical cardioversion: amiodarone, flecainide
• Catheter ablation
Anticoagulation – target INR 2-3
• Heparin
• Warfarin
• NOACs e.g. rivaroxaban

Question 9

What are the complications of atrial fibrillation/flutter?

Answer 9

• Thromboembolism -> 4% stroke risk per year
• MI
• CCF