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.
Anticoagulation in acute AF.
Heparin until a full risk assessment for emboli has been done.
Use DOAC or warfarin if high risk of emboli
Use no anticoagulation if stables sinus rhythm has been restored, no risk factors for emboli and AF recurrence is unlikely.
Chronic AF needs assessment of risk of stroke or systemic embolism.
How is this done?
By CHA2DS2VASc score.
Explain CHA2DS2VASc
Congestive cardiac failure (1)
Hypertension (1)
Age >74 (2)
Diabetes (1)
Stroke/TIA/Thromboembolism (2)
Vascular disease (1)
Age 65-74
Sex category (1 if female)
What does a score of 2 or more tell you?
Significant risk of embolic stroke.
This is high enough to offer anticoagulation.
What does a score of 1 in men tell you?
Considered intermediate risk - anticoagulation should be considered and a careful decision has to be made keeping in mind the bleeding risk.
What does a score of 0 tell you?
A truly low risk of stroke and anticoagulation is not offered.
What does a score of 1 in women (due to gender) tell you?
Considered low risk with anticoagulation not advised.
How is bleeding risk assessed?
HAS-BLED score
Explain HAS-BLED score.
It is not intended to withhold anticoagulation but to inform discussions and enable identification and optimisation of reversible risk factors for bleeding.
1 point for each;
Labile INR
Age >65
Use of medication that predispose to bleeding
Alcohol abuse (aspirin, NSAIDs)
Uncontrolled hypertension
History of or predisposition to major bleeding
Renal disease
Liver disease
Stroke history
Everyone with AF should have rate control as first line unless…
There is reversible cause for their AF
Their AF is of new onset (within the last 48 hours)
Their AF is causing heart failure
They remain symptomatic despite being effectively rate controlled
Indications for rhythm control.
There is a reversible cause for their AF
Their AF is of new onset (<48 hours)
Their AF is causing heart failure
They remain symptomatic despite being effectively rate controlled
What types of pharmacological rhythm controls are there?
Fleicainide
Amiodarone (if structural heart disease)
Long term medical rhythm control
Beta blockers
Dronedarone 2nd line
Amiodarone if heart failure or left ventricular dysfunction
