Atrial fibrillation

Question 1

What is atrial fibrillation?

Answer 1

Most common tachyarrhythmia.

Characterised by an irregularly irregular pulse, rapid heart rate and ECG changes.

Question 2

What are the signs and symptoms of atrial fibrillation?

Answer 2

None.
Palpitations.
Dyspnoea.
Syncope.
Exercise intolerance.
Fatigue.
Heart failure.
Irregularly irregular pulse.

Question 3

What are the causes of atrial fibrillation?

Answer 3

Idiopathic.
Ischaemic heart disease.
Heart failure.
Valve disease: mitral stenosis and mitral regurgitation.
Hypertension.
Hyperthyroidism.
Alcohol induced.
Familial.

Question 4

What are the complications of atrial fibrillation?

Answer 4

Stroke.
Heart failure.
Sudden death.

Question 5

What investigations should be performed for suspected atrial fibrillation?

Answer 5

ECG: absent P waves, irregular RR intervals, an undulating baseline and narrow QRS complexes.
Holter monitoring: ambulatory ECG device.
ECHO.
TFTs.
CXR.

Question 6

What is the conservative treatment of atrial fibrillation?

Answer 6

Patient education and management of cardiovascular risk factors, e.g. smoking cessation and decreasing alcohol intake.

Question 7

What is the medical treatment of atrial fibrillation?

Answer 7

Treat underlying cause.
Restore rate: beta blocker, calcium antagonist, digoxin, amiodarone.
Restore rhythm: beta blocker, cardioversion, amiodarone.
Anticoagulatn, e.g. warfarin, apixaban, dabigatran and rivaroxaban.

Question 8

Describe the pathophysiology of atrial fibrillation.

Answer 8

Atrial ectopic beats, thought to originate in the pulmonary veins, lead to disfunction of the cardiac electrical signalling pathway. As a result the atria no longer contract in a coordinated manner. Instead they fibrillate and contract irregularly. Due to the irregular contractions, the atria fail to empty adequately. This may result in stagnant blood accumulating within the atrial appendage, increasing the risk of clot formation and therefore embolic stroke.