AF

Question 1

What is AF?

Answer 1

Irregular/disorganised rhythm of atria

Disorganised firing of signals from atria

Question 2

What are the causes?

Answer 2

• HTN
• T2DM
• Hyperthyroidism

Question 3

How does AF increase the risk of stroke

Answer 3

There is a standstill of blood in the atria, which increases the risk of thrombosis (stroke)

Question 4

What are the 3 classifications of AF?

Answer 4

• proximal
• persistent
• permanent

Question 5

Describe Proximal AF

Answer 5

• lasts 30mins + BUT less than 7 days
• self terminating
• recurrent

Question 6

Describe Persistent AF

Answer 6

• lasts -/+ 7 days
• requires chemical or physical Cardioversion

Question 7

Describe Permanent AF

Answer 7

• does not terminate with Cardioversion
• or if terminates it returns within 25 hours

Question 8

Detecting AF in people with irregular pulse, with or without:

Answer 8

• SOB
• palpitations
• chest pain
• stroke/TIA

Question 9

Diagnosis/Investigations of AF

Answer 9

• Echo
• ECG

Question 10

AF increases stroke risk by how many folds?

Answer 10

5 folds

Question 11

List general ADRs of antiarythmics

Answer 11

Gi disturbances:
• nausea
• vomiting
• diarrhoea

CNS disturbances:
• hallucinations
• nightmares
• depression
• psychosis
• sezuires

Others:
• pro arrhythmic- TDP
• visual disturbances

Question 12

List non drug therapy approaches in AF

Answer 12

• defibrillators
• cardioversion
• pacemakers
• interval Cardioversion defibrillators

Question 13

Why may patients avoid antiarythmics?

Answer 13

• can cause new arrhythmia
• can increase the frequency of arrhythmia
• can cause ventricular tachycardia (TDP)

Question 14

What is “Vaugh Williams classification” regarding antiarythmics?

Answer 14

These agents are classified based on their electrical activity towards myocardial cells

Question 15

List the classes of agents

Answer 15

Class 1a = disopydramide
Class 1b = lidocaine
Class 1c = flecainide
Class 2 = beta blockers
Class 3 = amidarone
Class 4 = non-diydrophyradines - CCBs

Question 16

Which phases of the action potential do they affect

Answer 16

Class 1 (all) - phase 0
Class 2 - phase 4
Class 3 - phase 3
Class 4 - phase 2

Question 17

What is the MOA of class 1 agents?

Answer 17

Block na ions from entering voltage gated na channels - this slowing down electrical activity/AP - during phase 0

Question 18

What is the MOA of class 2 agents?

Answer 18

Beta blockers

• inhibits effects of sympathetic nervous system
• negative inotrope (decrease contractility)
• negative chronotrope (slows down heart rate)

• during phase 4

Question 19

What is the MOA of class 3 agents

Answer 19

• blocks k channels, thus prolonging AP duration

Question 20

What is the MOA of class 4 agents?

Answer 20

Blocks ca ions - during phase 2

Question 21

What is the main reason behind managing arrhythmia?

Answer 21

Prevent/avoid stroke

^ asses stroke and bleeding risk

Question 22

CHA2DS2-VASC is used to assess what? And in which patients?

Answer 22

Stroke risk (thrombotic) in patients with the following:
• asymptomatic/symptomatic AF
• atrial flutter
• risk of recurrent arrhythmia after Cardioversion

Question 23

What does CHA2DS2-VASC stand for?

Answer 23

• congestive cardiac disease
• HTN (including history)
• Age: 75 and over
• Diabetes
• Stroke/TIA
• Vascular disease
• Age: 65-74
• Sex: female

Each score 1 point
Stroke and Age (75+) score 2 each

Question 24

CHA2DS2-VASC - when to anticoagulant

Answer 24

•Score 2 or more (both genders) = offer anticoagulants
•Score 1 in men = consider anticoagulants
•Score 1 in women = NONE
•Score 0 (both genders) = NONE

Question 25

ORBIT is used to assess what?

Answer 25

Bleeding risk when: • starting new anticongulant OR • review those already on it.

Question 26

List MODIFIABLE risk factors for bleeding

Answer 26

• poor control of INR • HTN • concurrent use of: NSAID + SSRIs + antiplatlets • anaemia • renal and hepatic impairment

Question 27

List NON- MODIFIABLE risk factors for bleeding

Answer 27

• older age • hx of bleeding • hx of stroke • cancer • liver disease • dialysis

Question 28

What is the Treatment for valvular AF

Answer 28

Warfarin

Question 29

What is the Treatment for non-valvular AF

Answer 29

After calculating stroke risk with scoring system - DOACs

Question 30

Which rate controlling drugs can be given?

Answer 30

Beta blocker (not sotalol) OR Non dihydropyradine CCB • diltiazem (off label) • verapamil

Question 31

DOACs advantages and disadvantages

Answer 31

Advantages: • quick onset of action • therapeutic activity is predictable • target enzyme specificity • fewer drug-drug interactions • as affective as warfarin, with less intercrainial haemorrhage Disadvantage • more frequent dosing than warfarin (reason for no compliance) • lack of long term safety data • expensive • short half life • no commercially available antidote • no evidence for efficacy in valvular AF

Question 32

Warfarin Advantages and disadvantages

Answer 32

Advantages; • cheap • gold standard- used for 50> years • antidote - vitamin K • prescriber familiar with management and ADRs • once daily dosing (better compaince) Disadvantages • drug to drug interactions • food to food interaction • slow onset of action • requiring INR testing • narrow therapeutic windows • unpredictable therapeutic response