Atrial fibrillation/flutter Flashcards
Define atrial fibrillation
Characterised by rapid, chaotic & ineffective atrial electrical conduction
Aetiology of atrial fibrillation
2 + 3 groups of 2º
May be no identifiable cause
Secondary causes lead to an abnormal atrial electrical pathway that results in AF
Systemic causes
Heart causes
Lung causes
Epidemiology of atrial fibrillation
age x2, other
VERY COMMON in elderly
Ppresent in 5% of over 65s
May be paroxysmal
Presenting symptoms of atrial fibrillation
4
Often ASYMPTOMATIC
Palpitations
Syncope (if low output)
Symptoms of the cause of AF
Signs of atrial fibrillation on physical examination
3
- Irregularly irregular pulse
- Difference in apical beat & radial pulse
- Check for signs of thyroid & valvular disease
Investigations for atrial fibrillation
3 types
ECG
Bloods
Echocardiogram
Management of atrial fibrillation
general + 3 groups
Try to treat any reversible causes (e.g. thyrotoxicosis, chest infection) then 2 main components of management:
Rhythm control
Rate control
Stroke risk stratification
Complications of atrial fibrillation
2 +1
THROMBOEMBOLISM
- embolic stroke risk of 4% per year
- risk inc. w/ L atrial enlargement of L ventricular dysfunction
Worsening of existing heart failure
Prognosis of atrial fibrillation
Chronic AF in a diseased heart doesn’t usually return to sinus rhythm
Subdivisions of atrial fibrillation
- Permanent
- Persistent
- Paroxysmal
Aetiology of atrial fibrillation - systemic causes
4
Thyrotoxicosis
Hypertension
Pneumonia
Alcohol
Aetiology of atrial fibrillation - heart causes
7
Mitral valve disease Ischaemic heart disease Rheumatic heart disease Cardiomyopathy Pericarditis Sick sinus syndrome Atrial myxoma
Aetiology of atrial fibrillation - lung causes
2
Bronchial carcinoma
PE
Investigations for atrial fibrillation - ECG
3
Uneven baseline w/ absent p waves
Irregular intervals between GRS complexes
Atrial flutter = saw tooth
Investigations for atrial fibrillation - bloods
4
Cardiac enzymes
TFT
Lipid profile
U&Es, Mg2+ & Ca2+
due to increased risk of digoxin toxicity w/ hypokalaemia, hypomagnesaemia, hypercalcaemia
Investigations for atrial fibrillation - echocardiogram
4
May show: mitral valve disease left atrial dilatation left ventricular dysfunction structural abnormalities
Management of atrial fibrillation - rhythm control
1 >48hr, 2 <48hr, 4 prophylaxis
If >48 hrs since onset of AF
Anti coagulate for 3-4 weeks before attempting cardioversion
If <48 hrs since onset of AF
DC cardioversion
Chemical cardioversion: flecainide or amiodarone
Prophylaxis against AF Sotalol Amiodarone Flecainide Consider pill-in-the-pocket strategy for suitable patients
Management of atrial fibrillation - rate control
4
Chronic AF (permanent) Control ventricular rate: digoxin verapamil β-blockers Aim for ventricular rate 90bpm
Management of atrial fibrillation - stroke risk stratification
(4)
Low risk patients can be managed w/ aspirin
High risk patients require anticoagulation w/ warfarin
Based on CHADS-Vasc score
