Atrial Fibrillation Flashcards
What is atrial fibrillation
Irregularly Irregular atrial firing due to AV Delay
What is the epidemiology of AF
Most common Cardiac arrythmia
Increases with age
What is the pathology behind AF
Inflammation and fibrosis dilates the atria causing change in the refractory period.
Electrical re-entrant pathway is conducted in the atria leading to uncoordinated contractions.
The AVN only conducts some of these contractions leading to irregular ventricular response (Atrial Spasm and Atrial pooling)
How would you describe the Pulse in AF
Irregularly Irregular
What are some causes of AF
Heart fail
HTN
Secondary to mitral stenosis
What are the ris factors of AF
>60 Diabetes HTN CAD MI
What is the symptoms of AF
Palpitation
Chest pain
SOB
Dizzy
What are the signs of AF
Irregularly irregular pulse Apical>Radial pulse Heart fail Hyperthyroid Alcohol Excess
What does an ECG show for AF
Irregular Pulse Narrow QRS No P waves Variable Ventricular rate Absent Isoelectric line
How would you define AF
Ventricular rate >100bpm
What is the first rule of management of AF
ABCDE Asses haemodynamic stability -Shock = end organ hypoperfusion -Syncope = Brain hypoperfusion -Chest pain = MI -Pulmonary oedema = Heart fail
When should you offer Immediate DC CARDIOVERSION
If the patient is unstable
How would you treat the reversible causes of AF
Infection - give antibiotics and fluid
Dehydration - give fluids
Replace abnormal electrolytes
When would you offer Rate control
Everyone with AF EXCEPT….
- AF with reversible cause
- Heart failure
- New AF onset
What would you offer for rate control of AF
Beta Blocker (Bisoprolol) or Rate limiting CCB (Diltiazem) Digoxin
When would you offer digoxin
Non paroxysmal AF Hypotensive patient Existing Heart fail Avoid in young patients (high mortality) Normally used 2nd to beta blocker
Which beta blocker cannot be used in AF
Sotalol
-Rhythm control action
When are Beta blockers Contraindicated
COPD, Asthma and Hypotension
Which two CCB are commonly used in AF (Non-dihyropyridine)
Diltiazem
Verapamil
-Not used in Hospital because negatively inotropic so CI in Heart fail
How can you achieve Rhythm control
Electrical cardioversion
Pharmacological Cardioversion
When can a patient have immediate DC cardioversion
When AF is Acute <48hrs
What is the management of AF if it has been over 48hrs or the cause is uncertain
Anticoagulation 3 weeks before DC cardioversion
Do a Transoesophageal ECHO to rule out LA thrombus
What is the pharmacological cardioversion drugs used in AF
Flecainide (Pill in pocket)
Amiadarone(Rate and rhythm control)
Sotalol (Last resort)
What AF drug would you give to a patient who is young with structurally sound hearts
Flecainide
They cause arrythmias in patients with heart structure problems
What AF drug would you give to elderly patients
Amiadarone
Highly effective but give to elderly because they have many side effects
Why should anticoagulation be given with AF
AF has a high chance of thromboembolism thus stroke so risk needs to be decreased
What is the scoring system for Anti-coagulation typically with AF
CHADS2VASc C- Cardiac fail = 1 H- HTN = 1 A - Age over 75 = 2 D - Diabetes Mellitus =1 S - Stroke/TIA = 2 V - Vascular disease = 1 A- Age 65-74 = 1 Sc - Female = 1
What score is needed on CHADS2VASc for anticoagulation
Male = 1 or more Female = 2 or more
How would you assess bleeding risk with anticoagulation
HASBLED H- HTN = 1 A- Abnormal renal/Liver function = 1 each S- Stroke = 1 B- Bleed is major = 1 L- Labile INR = 1 E- Elderly over 65 = 1 D- Drugs and Alcohol = 1 each
What is the newly presented score for measuring anticoagulation
ORBIT score
- Sex
- Haemoglobin (<13M OR <12F)
- Age
- Bleeding
- Renal function (eGFR<60)
- Antiplatelet use
Why is there a high risk of stroke from AF
Blood stagnates in the atria due to invariable contractions and poor emptying
Blood embolises and can travel to the brain via the carotids
What are the three forms of anticoagulation used in AF
DOAC
Warfarin
LMWH
Why are DOACS the drug of choice for anti coagulation
Edoxaban-Apixaban-Dabigatran
Do NOT require monitoring
Less bleeding risks than Warfarin
But has short half life
What are the characteristics of Warfarin
Prothrombotic so needs LMWH initially
Requires INR monitoring
But has longest half life
The only drug for Valvular AF
Give an example of LMWH
Enoxaparin
What is Atrial Ablation
Intervention which destroys conduction tissue
What are the complications of AF
Heart fail
Embolism (stroke and ischemia)
GI Bleed
What are the types of intervention for AF
DC cardioversion (Rhythm control) Rate control Pharmacological Cardioversion Anticoagulation Atrial Ablation
What is the HASBLED score
Asses risk of major bleed in AF w/anticoagulation
>3 = regular review
