Atrial fibrillation

Question 1

What is atrial fibrillation?

Answer 1

Chaotic and disorganized atrial activity produces an irregular heartbeat

Question 2

Aetiology of atrial fibrillation?

Answer 2

Hypertension and heart failure are the most common causes

Question 3

What is the typical bpm for atrial fibrillation?

Answer 3

300-600 bpm

Question 4

What are the types of atrial fibrillation?

Answer 4

• Acute: lasts less than 48 hours
• Paroxysmal: lasts less than 7 days and is intermittent
• Persistent: lasts more than 7 days but is amenable to cardioversion
• Permanent: lasts longer than 7 days and is not amenable to cardioversion

Question 5

Signs of atrial fibrillation?

Answer 5

• Irregularly irregular pulse rate with a variable volume pulse
• A single waveform on the jugular venous pressure
• An apical to radial pulse deficit
• On auscultation there may be a variable intensity first heart sound.
• Features suggestive of the underlying cause (e.g. hyperthyroidism, alcohol excess, sepsis)
• Features suggestive of complications resulting from the AF (e.g. heart failure)

Question 6

Symptoms of atrial fibrillation?

Answer 6

• Incidental finding in ~30% of patients
• Palpitations
• Chest pain
• Shortness of breath
• Dizziness

Question 7

ECG features of atrial fibrillation?

Answer 7

• Atrial rate >300 bmp
• Irregularly irregular rhythm
• No P waves - irregular baseline
• Narrow QRS

Question 8

Treatment for AF in patients with life-threatening haemodynamic instability?

Answer 8

emergency electrical cardioversion

Question 9

All patients with AF should have rate control as first line except in what circumstances?

Answer 9

• There is a reversible cause for their AF
• Their AF is of new onset
• Their AF is causing heart failure
• They remain symptomatic despite being effectively controlled

Question 10

What are options for rate control in AF?

Answer 10

1. β-blocker e.g. atenolol is first line, OR rate-limiting CCB e.g. diltiazem (CCB not preferable in heart failure)
2. Digoxin (only in sedentary people, needs monitoring and risk of toxicity)

Question 11

When can rhythm control be offered to patients?

Answer 11

• There is a reversible cause for their AF
• Their AF is of new onset (<48 hours)
• Their AF is causing heart failure
• They remain symptomatic despite being effectively rate controlled