Atrial Fibrilation

Question 1

Symptoms of AF

Answer 1

Asymptomatic
Palpitations
Dyspnoea
Fatigue
Dizziness
Angina
Syncope

Question 2

Signs of AF

Answer 2

Pulse is irregularly irregular
Tachycardia
Raised JVP
S3 heart sound

Question 3

Pathophysiology of AF

Answer 3

Disorganised contraction of the atria (rapid irregular twitching)
Possibly due to multiple small reentry loops in the atria

Question 4

Investigations of AF

Answer 4

ECG would show absent P-waves, tachycardia, irregularly irregular rhythm

Question 5

Management of AF

Answer 5

Give:
Warfarin (stroke prevention)
Flecainide (rhythm control)
B-blocker/digoxin (rate control)

Lifestyle advice - reduce CVS risk factors

Question 6

Mechanism of action of warfarin

Answer 6

Inhibits production of Vitamin K dependent clotting factors (2,7,9,10) by inhibiting the reduction of Vit K back to its active form

Question 7

ADRs and DDIs of warfarin

Answer 7

ADRs: haemorrhagic eg. GI bleed/epistaxis/intracranial/excessive bruising, teratogenic in 1st trimester

DDIs: CYP450 inducers inhibit warfarin, inhibitors potentiate effects of warfarin. Aspirin, cephalosporin antibiotics and NSAIDs also potentiate effects

Question 8

Mechanism of action of flecainide

Answer 8

Na channel blocker, reduces rate of depolarisation in the AP, so prevents premature beats

Question 9

ADRs and contraindications of flecainide

Answer 9

ADRs: proarrhythmic, drowsiness, dizziness, GI disturbance
Contraindications: IHD, structural heart defects

Question 10

Causes of AF

Answer 10

Idiopathic
Ischaemic heart disease 
Thyroid disease 
Hypertension
MI
PE
Valve disease (mitral/tricuspid) 
LV dysfunction 
Alcohol

Question 11

AF differential diagnosis

Answer 11

Atrial flutter
Wolf-Parkinson-White syndrome
Atrial tachycardia