Atrial fibrillation Flashcards
What is atrial fibrillation?
Irregularly irregular pulse
Uncoordinated atrial contraction
Why does AF occur?
SA node is disorganised, causing the contraction of the atria to become uncoordinated, rapid and irregular.
This electrical activity is passed through to the AVN node in the ventricles, resulting in irregularly irregular ventricular contraction.
Uncoordinated atrial activity means the blood can stagnate in the atria, forming a blood clot.
If a blood clot is formed in the left atrium, it may travel to the brain and block a cerebral artery, causing an ischaemic stroke.
Symptoms/signs of AF?
palpitations
dyspnoea
chest pain
SOB
dizziness/lightheadedness
syncope
irregularly irregular pulse
features of underlying cause of AF, e.g. hyperthyroidism, sepsis, alcohol excess, dehydration, HTN, PE, pneumonia, rheumatic heart disease, hypokalaemia, hypomagnesaemia.
features of complications of AF, e.g. HF, PE
IVx for AF?
ECG (no P waves, absence of isoelectric line)
Bloods (check for infection or underlying cause e.g. hyperthyroidism or alcohol use)
Echo (check for cardiac cause e.g. left atrial dilation due to mitral valve disease)
Management of acute AF?
If pt shows signs of shock, syncope, myocardial syncope, HF, then 1st line synchronised DC cardioversion +/-amiodarone.
If no above adverse signs,
stable + onset <48h: rate or rhythm control (fleicanide -no structural heart disease or amiodarone -structural heart disease)
stable + onset >48h: rate control (BB, diltiazem/verapamil, digoxin)
Management of chronic AF?
Rate control = accept that the pulse will be irregular, but slow the rate down to avoid negative effects on cardiac function
e.g. 1st line -BB or diltiazem or verapamil, 2nd line -dual therapy BB and diltiazem, digoxin (for non-paroxysmal AF who are sedentary)
Rhythm control = maintain normal sinus rhythm (aka cardioversion)
e.g. electrical cardioversion, or pharmacological cardioversion -amiodarone, fleicanide or sotalol.
What is CHADS2VASc score? Male score of 1 or female score of 2 means?
Assesses risk of stroke in pts with AF.
C: 1 point for congestive cardiac failure.
H: 1 point for hypertension.
A2: 2 points if the patient is aged 75 or over.
D: 1 point if the patient has diabetes mellitus.
S2: 2 points if the patient has previously had a stroke or transient ischaemic attack (TIA).
V: 1 point if the patient has known vascular disease.
A: 1 point if the patient is aged 65-74.
Sc: 1 point if the patient is female.
Pt should be anticoagulated (as long as the risk of stroke outweighs the risk of bleeding).
What is ORBIT score?
Assesses risk of bleeding.
Sex
Haemoglobin (<13mg/Dl in males, <12mg<dL in females) 2 points
Age (>74) 1 point
Bleeding history 2 points
Renal function (eGFR <60) 1 point
Concomitant use of anti-platelets 1 point
Complications of AF?
Most complications are either from uncontrolled heart rate, embolism or from anticoagulation.
HF
Ischaemic stroke
Mesenteric ischaemia
Acute limb ischaemia
GI or intracranial bleed
