Atrial fibrillation

Question 1

what are the three different types of AF?

Answer 1

• paroxysmal
• persistant
• permenant (chronic)

Question 2

what is paroxysmal AF?

Answer 2

lasting less than 48 hours and often recurrent

Question 3

What is persistant AF?

Answer 3

• an epsiode of AF lasting greater than 48hours which can still be cardioverted to NSR
• unlikely to spontaneously revert to NSR

Question 4

What is permanent AF?

Answer 4

inability of pharmacologic or non-pharmacologic methods to restore NSR

Question 5

List some causes of AF? (15

Answer 5

-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

Question 6

what is lone AF? is there a stroke risk?

Answer 6

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

Question 7

what are 7 symptoms of AF?

Answer 7

Palpitations

Pre-syncope (dizziness)

Syncope

Chest pain

Dyspnea

Sweatiness

Fatigue

Question 8

What is the patholophysiology of AF?

Answer 8

• multiple wavelets of reentry

- ectopic focuse around the pulmonary veins

Question 9

What is seen on ECG in atrial fibrillation?

Answer 9

• 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

Question 10

what does an atrial rate of <60bpm suggest in AF?

Answer 10

AV conduction disease:

• caution with antiarrythmic and rate controlling drugs
• may require permanent pacing

Question 11

What is the general management of AF?

Answer 11

Rhythm control
Rate control
Anticoagulation if high risk thromboembolism

Question 12

What can be used to rate control AF? 3

Answer 12

• BBlockers
• digoxin
• Verapamil/diltiazem

Question 13

What is used to rhythm control AF?

Answer 13

Restoration of NSR:

• Amiodarone
• flecainide if no structural heart disease
• DCCV

Maintenance of NSR:

• antiarrythmic drugs
• catheter ablation of atrial focus/pulmonary veins

Question 14

What are:
Class 1
Class II
Class III
Class IV
antiarrythmic drugs and what do they do?

Answer 14

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

Question 15

How do you work out indication for anti-coagulation in atrial fibrillation?

Answer 15

If it is valvular AF: MS and MR

If it is non-valvular and has a score above 2 on CHA2DS2VASC

Question 16

What is the CHADSVASc score?

Answer 16

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

Question 17

What score is used to assess risk of bleeding in patients with AF on anticoag? what does this indicate?

Answer 17

HASBLED score

Score >= 3 high risk - justifies caution or more regular review

Question 18

What is the HASBLED score?

Answer 18

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

Question 19

How can radiofrequency ablation be used in AF?

Answer 19

Rate control - ablate AF focus

Rhythm control - ablate AVN to stop fast conduction to ventricles

Question 20

What is atrial flutter?

• is it permanent or paroxysmal?
• what is the pathophysiology?
• how long can episodes last?
• what can it progress to?

Answer 20

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

Question 21

What are the 4 different treatment for atrial flutter?

Answer 21

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