Atrial Fibrillation

Question 1

What is arrhythmia and what are the classifications and what should the normal heart rate be?

Answer 1

Arrhythmia= problem with the heart rate of rhythm
Classfication:
1. Bradycardia: slow heart rate (60BPM)
2. Tachycardia: increased heart rate (over 100BMP)
3. Normal heart rate= 60-100bpm

Question 2

What is Atrial Fibrillation

Answer 2

Atrial Fibrillation= type of arrhythmia and a major cause of stoke

Question 3

What are the symptoms of Atrial Fibrillation

Answer 3

Irregular pulse with or without the following
1. Breathlessness
2. Palpitations
3. Chest discomfort
4. Syncope or dizziness
5. Reduced exercise tolerance
could lead to stroke, transient ischaemic attack or heart failure

Question 4

What are the classifications of AF and explain them

Answer 4

1. Paroxysmal atrial fibrillation: episodes come and go, usually stop within 48 hours without treatment
2. Persistent atrial fibrillation: each episode last for longer than 7 days (or less when its treated)
3. Permanent atrial fibrillation: when it is present all the time

Question 5

What are the 3 things we need to manage to treat AF?

Answer 5

1. Rate control- elevated heart rate (tachycardia)
2. Rhythm control- abnormal heart rhythm
3. Anticoagulation- risk of stroke

Question 6

What drug are used to manage heart rate in AF

Answer 6

1. Beta blockers (not Sotolol)
2. Rate limiting (non-dihydropyridine) calcium channel blockers: verapamil or diltazem

Question 7

What is the mechanism of action for beta blockers in AF

Answer 7

1. Bind to beta 1 adrenergic receptor
2. Block norepinephrine from binding to receptor
3. This slows down the heart rate and decreases force of contraction in myocytes

Question 8

What is the mechanism of action for non-dihydropyridine calcium channel blockers in AF

Answer 8

1. Block L-type VGCC
2. reduces the influx of calcium ions into the cell
3. slows down electrical conduction in the heart which reduces heart rate

Question 9

What drugs can be used for rhythm control in AF, include their class

Answer 9

Amiodarone: Class III anti- arrhythmic
Sotalol: Beta blocker

Question 10

What is the mechanism of action for amiodarone

Answer 10

1. Blocks potassium currents that cause repolarisation in cardiac myocytes
2. Increases duration of action potential and maintains refractory period
3. Cardiac muscle cell excitability is reduced, preventing and treating abnormal heart rhythm

Question 10

What drug class are the following DOACs in: Apixaban, edoxaban, rivaroxaban and dabigatran

Answer 10

1. Apixaban: Factor Xa Inhibitor
2. Edoxaban: Factor Xa inhibitor
3. Rivaroxaban: Factor Xa inhibitor
4. Dabigatran: Direct Thrombin inhibitor

Question 11

Mechanism of action for Factor Xa inhibitors

Answer 11

1. Selectively inhibits Factor Xa
2. Factor Xa plays a role in the formation of blood clots
3. Blocking factor Xa will help prevent the formation of blood clots
4. Which helps reduce the risk of stroke- AF increases risk of stroke

Question 12

Mechanism of action for Direct Thrombin inhbitors

Answer 12

1.Inhibits thrombin which is a key enzyme involved in blood clotting
2.Blocking thrombin helps to prevent formation of blood clots

Question 13

Name 3 drugs in the vitamin K antagonist class

Answer 13

1. Warfarin
2. Acenocoumarol
3. Phenindone

Question 14

Mechanism of action for vitamin k antagonist

Answer 14

1. Inhibits vitamin k epoxide reductase
2. Inhibits the synthesis of clotting factors
3. Reduces formation of blood clots