Atrial Fibrillation Flashcards
Explain the normal progression of AF.
Initially manifesting as brief paroxysms of increasing duration. This is going on to peristent and permanent AF.
Main risk of AF.
Embolic stroke
Causes of AF.
Heart failure
HTN
IHD
PE
Mitral valve disease
Pneumonia
Hyperthyroidism
Caffeine
Alcohol
Post-op
Hypokalaemia
Hypomagnesaemia
etc…
Symptoms of AF.
May be asymptomatic
Chest pain
Palpitations
Dyspnoea
Faintness
Signs of AF.
Irregularly irregular pulse
Apical pulse rate is greater than radial rate.
1st heart sound is of variable intensity
Signs of LVF
Investigations done in AF.
Manual pulse to check for irregularity.
if it is irregular do an ECG.
Blood tests - U&E, cardiac enzymes and TFT.
Echo to look for left atrial enlargement, mitral valve disease, poor LV function etc…
If paroxysmal AF is suspected, what should be done?
Cardiac monitoring.
24h cardiac monitor is first line.
Prolonged holter monitor
Implantable loop recorder.
When is an echocardiogram done in AF?
If there is suspected structural heart disease.
When a rhythm control strategy (cardioversion) is being considered.
Baseline echo to inform long term management.
Management of acute AF.
If unstable -> DC cardioversion and amiodarone if unsuccessful. Do not delay this in order to start anticoagulation.
If patient is stable and AF started <48h ago:
Rhythm -> DC cardiovert or give flecainide if no structural disease.
Can also give amiodarone.
If the patient is stable and AF started >48h ago:
Rate control with bisoprolol or diltiazem. If rhythm control is chosen the patient must be anticoagulated for >3wks first.
Correct electrolyte imbalances.
Management of chronic AF.
Rate control and anticoagulation.
Rhythm control might be indicated.
When might rhythm control be indicated for AF?
Symptomatic or CCF
Younger patients
Presneting for 1st time with lone AF
AF from a corrected precipitant.
Rate control treatment in AF.
1st line = B-blocker (atenolol) or rate limiting Ca2+ blocker (diltiazem)
If this fails digoxin (if sedentary) can be considered, then amiodarone.
Digoxin should not be given as monotherapy, unless sedentary.
Do not give b-blocker with verapamil.
Aim for a heart rate of <90 bpm at rest and 200 minus age bpm on exertion.
Rhythm control treatment in AF.
Elective DC cardioversion - Do Echo first to check for intracardiac thrombi.
Pharmacological cardioversion - Flecainide 1st choice (CId in structural heart disease, use amiodarone instead).
What can be considered in refractory cases of chronic AF?
In refractory cases AVN ablation with pacing, pullmonary vein ablation or the maze procedure may be considered.
Treatment of paroxysmal AF.
Can be treated with “pill in the pocket” such as sotalol or flecainide PRN.