Atrial fibrillation Flashcards
what are the three different types of AF?
- paroxysmal
- persistant
- permenant (chronic)
what is paroxysmal AF?
lasting less than 48 hours and often recurrent
What is persistant AF?
- an epsiode of AF lasting greater than 48hours which can still be cardioverted to NSR
- unlikely to spontaneously revert to NSR
What is permanent AF?
inability of pharmacologic or non-pharmacologic methods to restore NSR
List some causes of AF? (15
-HTN
-Congestive heart failure
-Sick sinus syndrome: ‘tachy brady syndrome’
-Coronary heart disease
-Obesity
-Thyroid disease
-Familial
-Cardiac Valve disease
-Alcohol abuse
-Congenital heart disease
-Cardiac surgery
-COPD, Pneumonia,
-Septicaemia,
-Pericarditis, tumors
-Vagal cause – high
endurance athletess
what is lone AF? is there a stroke risk?
idiopathic AF: absence of any heart disease and no evidence of ventricular dysfunction
- diagnosis of exclusion
- could be genetic
- significant stroke risk if>75yrs old
what are 7 symptoms of AF?
Palpitations
Pre-syncope (dizziness)
Syncope
Chest pain
Dyspnea
Sweatiness
Fatigue
What is the patholophysiology of AF?
- multiple wavelets of reentry
- ectopic focuse around the pulmonary veins
What is seen on ECG in atrial fibrillation?
- irregularly irregular rhythm
- atrial rate > 300
- ventricular rate irregular and dependant on AVN conduction properties/sympathetic tone/parasympathetic tone/presence of drugs which act on AVN
- absence P waves
what does an atrial rate of <60bpm suggest in AF?
AV conduction disease:
- caution with antiarrythmic and rate controlling drugs
- may require permanent pacing
What is the general management of AF?
Rhythm control
Rate control
Anticoagulation if high risk thromboembolism
What can be used to rate control AF? 3
- BBlockers
- digoxin
- Verapamil/diltiazem
What is used to rhythm control AF?
Restoration of NSR:
- Amiodarone
- flecainide if no structural heart disease
- DCCV
Maintenance of NSR:
- antiarrythmic drugs
- catheter ablation of atrial focus/pulmonary veins
What are: Class 1 Class II Class III Class IV antiarrythmic drugs and what do they do?
Class 1: reducing Na channel current
Lignocaine, quinidine, flecainide,
propafenone
Class II: B-Adrenergic antagonists
Propranalol
Class III: action potential prolongation (block potassium channels)
Amiodarone, sotalol
DRONEDARONE
Class IV - Ca channel antagonists
Verapamil
How do you work out indication for anti-coagulation in atrial fibrillation?
If it is valvular AF: MS and MR
If it is non-valvular and has a score above 2 on CHA2DS2VASC
What is the CHADSVASc score?
C- CCF/LV dysfunction = 1 H- HTN = 1 A2 - Age>/= 75 = 2 D - DM = 1 S2 - previous stroke = 2 V - vascular disease = 1 A - age 65-74 = 1 S - sex (female) = 1
What score is used to assess risk of bleeding in patients with AF on anticoag? what does this indicate?
HASBLED score
Score >= 3 high risk - justifies caution or more regular review
What is the HASBLED score?
H - HTN = 1 A - abnormal renal or liver function = 1 or 2 S - stroke = 1 B - Bleeding = 1 L - labile INRs = 1 E - elderly > 65 = 1 D - drugs or alcohol = 1 or 2
How can radiofrequency ablation be used in AF?
Rate control - ablate AF focus
Rhythm control - ablate AVN to stop fast conduction to ventricles
What is atrial flutter?
- is it permanent or paroxysmal?
- what is the pathophysiology?
- how long can episodes last?
- what can it progress to?
Rapid and regular form of atrial tachycardia
Usually paroxysmal
Sustained by a macro-reentrant circuit which is confined to the right atrium
Episodes can last from seconds to years
Chronic atrial flutter usually progresses to atrial
fibrillation
May result in thrombo-emblism
What are the 4 different treatment for atrial flutter?
RF ablation (80-90% long term success)
Pharmacologic therapy:
Slow the ventricular rate
Restore sinus rhythm
Maintain sinus rhythm once converted
Cardioversion
Warfarin for prevention of thromboembolism
