Atrial Fibrillation

Question 1

What is atrial fibrillation ?

Answer 1

-When the contraction of the atria is uncoordinated, rapid and irregular.
-300-600 bpm

Question 2

How is AF caused?

Answer 2

heart failure, hypertension, mitral valve disease

Question 3

What can AF lead to?

Answer 3

Irregularly irregular ventricular contractions
Tachycardia
Heart failure due to poor filling of the ventricles during diastole
Risk of stroke

Question 4

What is the presentation of AF?

Answer 4

Palpitations
Shortness of breath
Syncope (dizziness or fainting)
Irregularly irregular pulse

Question 5

what are the differential diagnosis of irregularly irregular pulse?

Answer 5

Atrial fibrillation
Ventricular ectopics
Differentiated using ECG- regular heart rate during exercise would be ventricular ectopics

Question 6

What would AF look like on an ECG?

Answer 6

Absent P waves
Narrow QRS Complex Tachycardia
Irregularly irregular ventricular rhythm

Question 7

What is valvular AF?

Answer 7

• patients with AF who also have moderate or severe mitral stenosis or a mechanical heart valve. The assumption is that the valvular pathology itself has lead to the atrial fibrillation

Question 8

What is rate control?

Answer 8

Aim is to get heart rate below 100 to extend the time that ventricles can fill with blood
Beta blocker is first line (e.g. atenolol 50-100mg once daily)

Question 9

What is rhythm control?

Answer 9

• to return patient to normal sinus rhythm
• cardioversion used to correct this

Question 10

What are the cardioversion guidelines?

Answer 10

• Nice says pharmacological cardioversion first line- flecanide or aminodarone

Question 11

How does electrical cardioversion work?

Answer 11

• using defibrillator to deliver shocks to restore sinus rhythm

Question 12

What is first line for long term medical rhythm control?

Answer 12

• beta blockers
  -dronedarone (2nd)

Question 13

What is paroxysmal atrial fibrillation?

Answer 13

-AF comes and goes in episodes
- pill in pocket approach which is Flecanide

Question 14

What anticoagulants are used?

Answer 14

• warfarin (vitamin K antagonist) requires close monitoring of INR
• DOACS such as apixaban and dabigatran twice daily

Question 15

What are the advantages of DOACS over warfarin?

Answer 15

No monitoring is required
No major interaction problems (e.g cyp450)
Equal or slightly better than warfarin at preventing strokes in AF
Equal or slightly less risk of bleeding than warfarin

Question 16

What does CHA2DS2-VASc mnemonic stand for?

Answer 16

C – Congestive heart failure
H – Hypertension
A2 – Age >75 (Scores 2)
D – Diabetes
S2 – Stroke or TIA previously (Scores 2)
V – Vascular disease
A – Age 65-74
S – Sex (female)

0: no anticoagulation
1: consider anticoagulation
>1: offer anticoagulation

Question 17

What is used to assess bleeding risk?

Answer 17

• ORBIT tool
  -Low haemoglobin or haematocrit
  -Age (75 or above)
  -Previous bleeding (gastrointestinal or intracranial)
  -Renal function (GFR less than 60)
  -Antiplatelet medications