Atrial Fibrillation

Question 1

Define atrial fibrillation

Answer 1

Chaotic, rapid, ineffective electrical conduction of the atria.

Question 2

List 6 cardiac causes of atrial fibrillation.

Answer 2

• Mitral valve disease
• IHD
• Sick Sinuc Syndrome
• Pericarditis
• Atrial myxoma
• Cardiomyopathy

Question 3

List 6 non-cardiac causes of AF.

Answer 3

• Thyrotoxicosis
• Alcohol abuse
• Pneumonia
• PE
• Lung carcinoma
• HTN

Question 4

What are some possible symptoms of AF?

Answer 4

• Palpitations
• Syncope
• Dyspnoea
• Chest pain

Question 5

What signs would you find on examination of a patient with AF?

Answer 5

• Irregularly irregular pulse

- Apical-radical pulse deficit (Apical>radical)

Question 6

What investigations would you carry out for AF?

Answer 6

ECG: absent P waves, irregular QRS, uneven baseline Note: “saw-tooth” pattern is atrial flutter

BLOODS: TFTs, cardiac enzymes, U&Es, Ca/Mg/k
(check as hypercalcaemia, hypomagnesaemia and hypokalaemia predispose to digoxin toxicity)

ECHO: Check for structural abnormalities, mitral valve disease, thrombus for cardioversion

Question 7

How would you manage acute AF?

Answer 7

If the patient is haemodynamically unstable:
- Emergency cardioversion 
- If not available then:
VERAPAMIL or BISPROLOL
\+ DIGOXIN or AMIODARONE
\+ LMWH

Question 8

How would you manage chronic AF?

Answer 8

RATE, RHYTHM AND STROKE RISK CONTROL

RATE
1st line: VERAPAMIL or BISPROLOL
2nd: add DIGOXIN
3rd: add AMIODARONE

RHYTHM

1st: FLEICANIDE (if no structural abnormalities)
2nd: AMIODARONE (if structural abnormalities)

STROKE RISK CONTROL:
Low risk: Aspirin
High risk: Warfarin

Question 9

What are the possible complications of AF?

Answer 9

• thromboembolism – stroke

Question 10

What is the pathophysiology of AF?

Answer 10

Decreased cardiac output by 10-20%, due to incomplete filling of ventricles.

Question 11

Why should you not give VERAPAMIL and BISOPROLOL together?

Answer 11

Risk of inducing bradycardia.