Atrial Fibrillation

Question 1

What is AF?

Answer 1

A lack of coordination of electrical and therefore mechanical activity of the atria, leading to fibrillation of the two chambers

Question 2

What is the classical description of the AF pulse?

Answer 2

Irregularly irregular

Question 3

Where is the anatomical location of the source of the abnormal electrical activity? What is the rate at which contraction of the atria is stimulated?

Answer 3

Around the entrances of the 4 pulmonary veins into the left atrium. Contraction is at 300-600bpm

Question 4

What is the pathophysiology of AF?

Answer 4

The abnormal electrical activity from the left atria is conducted down through the AVN intermittently - not all the signals get through. As a result, the HR becomes irregular

Question 5

What are the causes of AF?

Answer 5

Most common is IHD, LHF and HTN 
Can also be remembered by the mnemonic PIRATES:
PE
IHD and Idiopathic 
Rheumatic heart disease 
Age and alcohol 
Thyroid disease - Hyperthyroidism 
Elevated BP - HTN
Surgery and sepsis

Question 6

What are the signs and symptoms for AF?

Answer 6

Asymptomatic 
Palpitations 
SOB
Feeling faint and dizzy (+/- syncope) 
Chest pain 
Irregularly irregular pulse
Murmurs indicating underlying causes

Question 7

What can acute severe AF present as?

Answer 7

Haemodynamic compromise - shock

Question 8

What are the ECG signs of AF?

Answer 8

Absent P waves
Jagged isoelectric line
Irregularly irregular rhythm
Possible signs of LVH or ischaemia

Question 9

What other Ix can you order for AF?

Answer 9

Most commonly normal
Bloods
TFTs - can show hyperthyroidism
Echo

Question 10

What is the management for acute AF?

Answer 10

A to E assessment, then proceed as below.
If haemodynamically unstable:
- Stabilise with A to E approach
- Emergency DC Cardioversion
If haemodynamically stable:
- If <48hrs, DC cardioversion or pharmacological rhythm management
- If >48hrs or unclear time of onset, Bisoprolol or Diltiazem for rate, then consider elective DC cardioversion after >3 weeks anticoagulation

Question 11

Why would you use rhythm control for chronic AF over rate control?

Answer 11

Both equally as good in the long term, so often stick with just rate (fewer side effects) unless:
- 1st presentation of Idiopathic AF
- Symptomatic
- Young
Rate drugs are more dangerous so would try to not give them

Question 12

What are the two main rhythm controlling drugs for AF?

Answer 12

Flecainide - 1st line
- BUT, CI in: structural heart damage and IHD
Amiodarone

Question 13

What is the management of chronic AF?

Answer 13

Rate and/or rhythm control

• Bisoprolol
• Diltiazem is another alternative - intermediate class of CCB
• Consider elective DC cardioversion after >3 weeks of anticoagulation
• Flecainide/Amiodarone
• Ablation

Anticoagulation

• Apixaban or other DOAC
• Warfarin IF: metal heart valve, pregnancy, renal failure, anti-phospholipid syndrome

Question 14

What are the two prognostic tools used for AF to determine anticoagulation management?

Answer 14

CHA2DS2-VASC - risk of ischaemic stroke secondary to AF

HAS-BLED score - risk of major bleed when on anticoagulation

Question 15

What is the main complication of AF?

Answer 15

Ischaemic stroke - thromboembolic