Atrial Fibrillation

Question 1

How common is it?

Answer 1

Most common cardiac arrythmia - 1% of population.

Question 2

Who does it affect?

Answer 2

Men more than women, prevalence increases with age.

Question 3

What causes it?

Answer 3

• Sinoatrial node of heart overwhelmed by disorganized atrial electrical discharge, often originating at pulmonary vein insertion.
• Idiopathic in 5-10% of cases.
• Loss of active ventricular filling is associated with stagnation of blood in the atria leading to thrombus formation and a risk of embolism, increasing the risk of stroke and also reduction in cardiac output (especially during exercise) which may lead to heart failure.

Question 4

What risk factors exist?

Answer 4

• Hypertension, primary heart diseases (CHD, valve disease etc.), lung pathologies, excessive alcohol consumption, hyperthyroidism, heart failure.

Question 5

What signs does it produce?

Answer 5

characterised by irregularly irregular ventricular pulse and loss of association between the cardiac apex beat and radial pulsation.

Question 6

Symptoms?

Answer 6

Palpitations, tired and/or breathless with exercise, sometimes angina and ankle oedema.

Question 7

What is seen on an ECG in AF?

Answer 7

absence of P waves, with disorganized electrical activity in their place, and irregular R-R intervals due to irregular conduction of impulses to the ventricles, QRS complexes narrow.

Question 8

What investigations should be carried out?

Answer 8

ECG
Blood tests - TFTs, FBC, renal function and electrolytes, LFTs, coagulation screen.
CXR
Echocardiogram

Question 9

What treatments would you consider?

Answer 9

• Management involves control of the arrhythmia and thromboprophylaxis, plus treatment of the underlying cause and associated heart failure.
• Rhythm control – flecainide, beta-blockers (sotalol), amiodarone, dronedarone.