Atrial Fibrillation Flashcards
Causes of AF?
Foci often in pulmonary veins; often only passive ventricular filling; rapid, irregular, and chaotic electrical activity in the atria
Differential?
- IHD, Thyrotoxicosis, RheumHD
- Alcohol, valvular heart disease, HTN, HF (i.e. stretch or stress on myocardium)
- Rare: Phaeochromocytoma, IE, Pericardial disease
Venricular ectopics (can diff by increasing heart rate, should remove ectopic), Atrial flutter with variable block, other arr
Why is pulse not same at wrist as at apex?
Apex rate may be higher because AF results in variable diastolic filling of ventricles - due to variable ventricular response to atrial stimuli.
This may be enough to result in valve closure on contraction, but not enough to propagate pulse to the wrist
Complications of AF
Complications of AF
6x higher risk of stroke
HF
Cardiomyopathy
Prognosis heaviliy influenced by underlying disease state - up to 30% of people with AF will be ASx
Management of AF
Thromboprophylaxis
Rate control - Beta-blockers or cardioselective CCB (never both - riskk HF). COnsider Digoxin in HF
Rhythm control - Fleicanide (pill-in-pocket), Amiodarone, Sotalol
Cardioversion as option (if thrombus ruled out in LV)
Catheter ablation - radiofrequeny or microwave ablation of aberrant foci
Maze or more likely mini-maze (minimally invasive; microwave or cryotherapy to create the scar tissue)
Acute AF - with fast ventricular response
How manage if haemodynamically unstable?
If present for less than 48 hours?
More than 48 hours?
If want to cardiovert later, what have to do beforehand?
Acute AF - with fast ventricular response
DC cardioversion
- If no structural heart disease - Fleicanide (careful if WPW)
- If sturctural heart disease - amiodarone
>48h
- x HF - BB or cardioselective CCB
- HF - Digoxin
Place all on LMWH/Warfarin
Echo before delayed cardioversion to rule out thrombus in LV