Atrial Fibrillation Flashcards
Define atrial fibrillation
Supraventricular tachyarrhythmia whereby there is rapid, chaotic and ineffective atrial electrical conduction.
What are the classifications of atrial fibrillation
Acute AF (≤48h)
Paroxysmal AF (self-limiting, <7d, recurs)
Persistent AF (>7d, may recur even after cardioversion)
Aetiology of atrial fibrillation
idiopathic
Systemic: Hyperthyroidism or thyrotoxicosis, Hypertension, Alcohol “holiday heart syndrome”, DM
Heart: Mitral valve disease (stenosis), IHD, Rheumatic heart disease, cardiomyopathy, pericarditis,
Lung: bronchial carcinoma, PE, pneumonia
Symptoms of atrial fibrillation
Often asymptomatic
Palpitations
Dizziness
Fall/syncope
Dyspnoea
Signs of atrial fibrillation on examination
Obs: hypotension
Cardio:
- Irregularly irregular pulse
- Apical and radial pulse different
- Raised JVP with absent a waves
- S3
± signs of underlying cause e.g. valvular disease, hyperthyroidism
Investigations for atrial fibrillation
ECG:
- Irregularly irregular rhythm
- P waves absent
- Fibrillations may be visible on baseline
- Either AF or fast AF (rate)
Troponin: exclude MI
Lipid profile
TFTs
U&Es
Magnesium + calcium
Echo: Assess for mitral valve disease, left atrial dilation, left ventricular dysfunction or structural abnormalities
CXR: ?pulmonary cause
Management for haemodynamically unstable Atrial Fibrillation
DC cardioversion
Management for haemodynamically stable Atrial Fibrillation within 48 hours of presentation
Time of presentation?
(1) rate control (BUT if reversible → correct cause → rhythm control)
(2)
< 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
Rate control:
1. Beta blockers (NOT sotalol) OR CCB (verapamil > diltiazem)
2. Digoxin (esp. in Heart Failure)
3. Amiodarone
Rhythm control: DC cardioversion OR chemical cardioversion with amiodarone/flecainide
- Flecainide CI in structural heart disease e.g. HF
- No response → catheter ablation
Anticoagulate:
1. LMWH until full assessmen
2. CHA2DS2VASc + ORBIT
- 0: no treatment → transthoracic echo
- 1: Males → consider anticoagulation | Females → no treatment
- 2: anticoagulation
3.
- Low risk: aspirin
- High risk: Warfarin OR DOAC e.g. apixaban
Catheter ablation if unsuccessful
TTO for atrial fibrillation
Anticoagulation after cardioversion
CHA2DS2VASc low → 4 weeks
CHA2DS2VASc high/paroxysmal AF → lifelong
What is given for paroxysmal atrial fibrillation
Prophylaxis with beta blocker (sotalol), amiodarone or flecainide
Complications of atrial fibrillation
Thromboembolism e.g. Stroke
Worsening of existing heart failure
MI
Prognosis for atrial fibrillation
Depends on several factors e.g. Precipitating event, underlying cardiac status, TE risk etc.
Young patient with no structural cardiac abnormalities with new onset AF due to alcohol binging -> excellent prognosis with alcohol avoidance
Chronic AF does not usually return to sinus rhythm
Increased risk of mortality with AF presence with MI
