Atrial Fibrillation Flashcards
What is atrial fibrillation?
A heart condition that causes a very fast heart rate. Caused by uncoordinated contractions of the atrium by disorganised electrical activity which overrides the SA nodes.
What are the 3 ECG changes seen with AF?
Absent P waves
Narrow QRS waves with tachycardia
Irregularly irregular ventricular rhythm.
How does AF present?
Often asymptomatic and picked up coincidentally. Palpitations dyspnoea fatigue dizziness weakness syncope chest pain
What is the pulse like in AF?
irregularly irregular.
which conditions cause an irregularly irregular pulse?
Atrial fibrilaltion
Ventricular ectopics
Sinus arrhythmia
What points the diagnosis towards ventricular ectopics and not AF?
The heart rate is normal on exercise (because in ventricular ectopics, over a certain heart rate the heart goes back to normal). AF has an abnormal heart rate and rhythm regardless.
what are the common causes of AF? SMITH
sepsis mitral valve pathology (regurgitation or stenosis) ischaemic heart disease thyrotoxicosis hypertension
What causes valvular AF?
Having a mechanical heart valve or mitral stenosis.
Other valve diseases are not though to cause AF.
What is the management for AF?
Rate control
Rhythm control
Anticoagulation
What is the rate control management for AF?
1st line - beta blocker (bisoprolol or atenolol)
2nd line - calcium channel blocker (diltiazem)
3rd line - digoxin
If one doesn’t work, use two medications together.
When can calcium channel blockers not be used?
NOT to be used in heart failure
When is digoxin used most commonly?
In sedentary people
Why does digoxin need to be monitored?
because theres a risk of toxicity.
Why is rate control important?
To get the HR below 100, to allow a longer period of time for the heart to be in diastolic to allow the ventricles to fill more leading to an increased cardiac output.
What is the treatment for rhythm control?
1st line - beta blocker (bisoprolol or atenolol)
2nd line - dronedarone
3rd line - amiodarone