Atrial Fibrillation

Question 1

Define Atrial Fibrillation

Answer 1

Supraventricular tachycardia whereby there is a rapid, chaotic and ineffective atrial electrical conduction

Question 2

Aetiology of Atrial Fibrillation

Answer 2

Idiopathic

Secondary to:
Systemic disease: HTN, Hyperthyroidis/thyrotoxicosis, pneumonia, alcohol, DM

Heart: Mitral stenosis, IHD, rheumatic heart disease, cardiomyopathy, pericarditis

Lung: bronchial carcinoma, PE

Question 3

Risk Factors for Atrial Fibrillation

Answer 3

Increasing age
DM, HTN, heart failure, Valvular disease, CAD
Hyperthyroidism
Atrial arrhythmia

Question 4

Epidemiology of Atrial Fibrillation

Answer 4

Most common sustained cardiac arrhythmia
incidence and prevalence rates higher in old people and developed countires
Incidence + prevalence lower in women, but higher mortality risk

Question 5

Presenting symptoms of Atrial Fibrillation

Answer 5

Often asymptomatic

Palpitations (irregular)
Dizziness, fall/syncope
Dyspnoea
Rales (HF)

Question 6

Signs of Atrial Fibrillation on examination

Answer 6

Irregularly irregular pulse
Hypotension
3rd heart sounds 
Raised JVP 
Signs of underlying cause e.g. thyrotoxicosis, valvular disease

Question 7

Investigations for Atrial Fibrillation

Answer 7

ECG: irregularly irregular rhythm with NO visible P waves + baseline fibrillations

Bloods (cardiac enzymes, trops, TFTs, lipid profile, U+Es) normal

Echo: normal or abnormal depending on cause (assess valvular disease etc.)

Question 8

Management for haemodynamically unstable Atrial Fibrillation

Answer 8

DC cardioversion

Question 9

Management for haemodynamically stable Atrial Fibrillation within 48 hours of presentation

Answer 9

Time of presentation?
< 48h → (1) anti-coagulate (2) TOE (3) cardiovert
- If TOE detects thrombus, postpone CV after longer period
> 48h → (1) anti-coagulate for 3-4 weeks (2) TOE (3) cardiovert

Rhythm control: DC cardioversion OR chemical cardioversion with amiodarone/flecainide
- Flecainide CI in structural heart disease e.g. HF

Rate control: beta blocker (digoxin in HF)

Anticoagulate:
Heparin
Calculate Chadsvasc + HASBLED
Warfarin OR DOAC

Catheter ablation if unsuccessful

Question 10

Management for haemodynamically stable Atrial Fibrillation after 48 hours of presentation

Answer 10

Rate control: beta blocker (digoxin in HF)

Anticoagulate:
Heparin
Calculate Chadsvasc + HASBLED
Warfarin OR DOAC

3-4 weeks later, DC cardioversion

Catheter ablation if unsuccessful

Question 11

Complications of Atrial Fibrillation

Answer 11

Thromboembolism -> Stroke
Worsening heart failure
MI

Question 12

Prognosis for patients with Atrial Fibrillation

Answer 12

Depends on many factors e.g. precipitating event, cardiac status, TE risk

Excellent prognosis in young patients with no cardiac abnormalities - alcohol avoidance

Chronic AF does not usually return to sinus rhythm
Increased risk of mortality