Atrial fibrillation Flashcards
What is AF?
Supraventricular tacharrhythmia characterised by ineffective, chaotic, irregular and rapid (300-600BPM) atrial activity -> deterioration of atrial mechanical function. Disorganised electrical activity
Irreguarly irregular rhythm
Risks for AF
Pirates
Pulmonary embolism
Ischaemia
Respiratory disease
Atrial enlargement or myxoma
Thyroid disease
Ethanol
Sepsis/sleep apnoea
Cardiac causes of AF
HPTN
IHD
HF
Sick sinus syndrome
Pericarditis
Infiltrative heart disease
Valvular HD - mitral
Cardiomyopathies
Myocarditis
Congenital HD
How to manage AF?
- Rate control
- Beta blockers, rate limiting CCBs, digoxin
- Rhythm control - DC eletrical cardioverison or amiodarone or flecainide
- Reduce clot risk - DOAC or warfarin
- Test clotting risk eg
- ORBIT scoring - replaced HASBLED ]
- CHA2DS2-Vasc scoring
- If chad higher than orbit offer anticoag
Atrial fibrillation on ECG
Irreguarly irregular pulse
No p waves
Paroxysmal vs persistent AF
Paroxysmal = over 30 s but under 7 days, self terminating and recurrent
Persistent = Episodes over 7 days
What is it called when AF fails to terminate?
Permanent AF
Terminated and relapses within 24 hours or long standing eg over a year
Rate control management in AF - when prefer over rhythm? What use?
BCD - over 65 or hx IHD
Beta blockers eg bisoprolol
Calcium channel blockers eg dilatezam
Digoxin
When is digoxin preferred in AF?
Co-existing HF or hypotension
When do you use rhythm control in AF?
Under 65 years, symptomatic, 1st presentation, lone AF or AF to a precipitant or CCF
What use in rhythm control for AF?
Chemical or electrical
Chemical = sotalol, Amiodarone, flecainide (in absence of structural HD)
Electrical - in acute scenario if patient is haemodynamically unstable ]or elective
How do you determine risk of stroke with AF?
CHADVASC score - need for anticoagulation vs HASBLED score - risk of bleeding with anticoagulants
What does the CHADVASC score consider?
Congestive cardiac failure
HTN
Age
Diabetees
Stroke or TIA prev = 2
Vascular disease
Sex - female = +1
How high does the CHADVASC score need to be to offer anticoagulation in AF?
> 2 or =
What does the HASBLED score consider?
HTN
Abnormal renal function or liver
Stroke or history of
Bleeding, history of or high risk of
Labile INRs (<60% therapeutic range)
Elderly
Drugs predisposing to bleeding, alcohol use
When is considered high risk of bleed with HASBLED score?
> 3 = high risk of bleeding
Non cardiac causes af
Sepsis
PE
Thyrotoxicosis
Lung or pleural disease
Chest trauma
Hypokalaemia
Hypovolaemia
Hypothermia
Alcohol abuse/drug abuse eg cocaine
Symptoms AF
Palpitations
Dyspnoea
Chest pain
Dizziness
Syncope
Fatigue
Signs AF
Irreguarly irregular pulse
Signs of HF
Complications AF
Stroke - 5x risk
HF
Tachycardia induced Cardiomyopathy + critical cardiac ischaemia
Bloods for AF
FBC
U+Es
TFTs
Magnesium
LFTas
Coag screen
Investigations AF
CXR - HF, mitral valve disease
ECG
ECHO - risk underlying structural/functional disease
CT/MRI brain - stroke/TIA suggestion
AF on ECG
No p waves - no synchronised depolarisation
Fibrillatory waves - no baseleine
F waves = flutter waves
Treatment for haemodynamically instability (hypotension, HF) in AF
Immediate elctric cardioversion
What treat haemodynamically stable AF if <48 hours onset
Rate or rhythm control
If uncertain/symptoms started over 48 hours agoAF
Rate control
What need to do before cardioversion if haemodynamically stable AF with unknown onset over 48 hours if considered for long term rhythm control
delay cardioversion until maintatined therapeutic anticoagulation for minimum of 3 weeks
Who is CI for rate control in AF
Reversible cause
HF caused by AF
New onset AF <48 hrs
Atrial flutter - condition suitable for ablation surgery to restore sinus rhythm
Ryhtm control strategy more suitable based on clinical judgement
AF rate controlling meds
Beta bocker - CI asthma
CCB
Digoxin
Rhythm control for AF
Beta blockers
Dronedarone
Amiodarone
What is second line in patients following cardioversion
Dronedarone
What amiodarone is particularly helpful
Coexisting HF with AF
When is catheter ablation used
THose with AF not repsonded to or want to avoid antiarrhtyhmic meds
What anticoagulation need to do for catheter ablation
4 weeks before and during the procedure
Still require anticoagulation after accoring to CHADVASC
How long give anticoagulation based on CHADVASC score
0 - 2 monhts
>1 - longterm
Complications of AF
cardiac tamponade
stroke
pulmonary vein stenosis
