Atrial fibrillation

Question 1

What is atrial fibrillation?

Answer 1

Where the electrical activity of the atria becomes disorganised, leading to fibrillation of the atria, and an irregularly irregular pulse

Question 2

What is the pathophysiology of AF?

Answer 2

Electrical activity from the SA node is disorganised, causing the contraction of the atria to become uncoordinated, rapid and irregular

These signals pass through to the ventricles causing irregularly irregular ventricular contraction

Question 3

What are the common causes of AF?

Answer 3

PIRATES
- Pulmonary - PE and COPD
- Ischaemic heart disease
- Rheumatic heart disease
- Anaemia, alcohol, advancing age
- Thyroid disease (hyperthyroidism)
- Electrolyte disturbance
- Sepsis and sleep apnoea

Question 4

What is the presentation of AF?

Answer 4

May be asymptomatic
Palpitations
SOB
Dizziness or syncope
Chest pain
Irregularly irregular pulse

Question 5

What are the differentials for an irregularly irregular pulse?

Answer 5

Atrial fibrillation
Ventricular ectopics

Question 6

What is the first line investigation (and findings) in AF?

Answer 6

ECG
- Absent P waves
- Narrow QRS complexes
- Irregularly irregular ventricular rhythm

Question 7

What other investigations can be useful in the diagnosis of AF?

Answer 7

Serum electrolytes
TFTs - hyperthyroidism as secondary cause
CXR - if suspicion of heart failure
TTE - consider if there is suspicion of underlying structural or functional heart disease

Question 8

What are the adverse features of AF?

Answer 8

Shock
Syncope
MI
Heart failure

Question 9

What is paroxysmal AF?

Answer 9

Episodes of AF that reoccur and spontaneously resolve back to sinus rhythm

Question 10

What additional investigations are useful in paroxysmal AF?

Answer 10

24 hour ambulatory ECG
Cardiac event recorder (for 1-2 weeks)

Question 11

What is management of AF in a haemodynamically unstable patient?

Answer 11

Emergency electrical synchronised DC cardioversion

Question 12

What is the management of new AF < 48 hours in a stable patient ?

Answer 12

Rate control
or
Rhythm control (immediate cardioversion) - electrical or pharmacological

Question 13

What are the options for rate control in AF?

Answer 13

First line - beta blocker (bisoprolol)
Calcium channel blocker - verapamil or diltiazem (not in HF)
Digoxin - first line in patients with HF

Question 13

What are the options for rhythm control?

Answer 13

Immediate cardioversion
- Pharmacological - flecainide or amiodarone
- Electrical - DC cardioversion

Delayed cardioversion

Question 14

What is the management of AF > 48 hours or unknown onset?

Answer 14

Offer rate control and anticoagulation for 3 weeks
- Offer rhythm control (DC cardioversion) if rate control is unsuccessful

Question 15

What is the management of paroxsymal AF?

Answer 15

If infrequent episodes and no structural heart disease:
- Flecainide when they have symptoms

Question 16

When is ablation for atrial fibrillation indicated?

Answer 16

When drug treatment has failed to control symptoms, or is unsuitable

Question 17

What are the options for ablation in AF?

Answer 17

Left atrial ablation
- catheter through the femoral vein under general anaethetic to ablate abnormal pathways

AV node ablation and permenant pacemaker
- destroys connection between atria and ventricles
- a permenant pacemaker is required to control ventricular contraction

Question 18

What are the complications of AF?

Answer 18

Stroke
MI
Heart failure

Question 19

What are the first line anticoagulants in AF?

Answer 19

DOACs

Question 20

What is the second line anticoagulant in AF?

Answer 20

Warfarin