Anti-arrhythmics

Question 1

What type of drug are class 1 anti-arrhythmics?

Answer 1

Sodium channel blockers

Question 2

Give an example of a class 1 anti-arrhythmic

Answer 2

Flecainide

Lidocaine

Question 3

What is the action of Class 1 anti-arrhythmics? (3)

Answer 3

Bind and block sodium channels
Reduces phase 0 (depolarisation)
Decrease AP amplitude

Question 4

Name another condition that sodium channel blockers can be used for

Answer 4

Epilepsy

Question 5

What type of drug is a class 2 anti-arrhythmics?

Answer 5

Beta blockers

Question 6

What is the action of class 2 anti-arrhythmics? (4)

Answer 6

Blocks sympathetic activity
Reduces rate and conduction of AP
Slows down phase 4 (prolongs time between AP)
Lowers HR

Question 7

Give an example of a beta blocker

Answer 7

Atenolol

Bisoprolol

Question 8

What can beta blockers also be used for?

Answer 8

Hypertension

Heart failure

Question 9

How would you treat a beta blocker overdose?

Answer 9

Give atropine

Glucagon is atropine is not successful

Question 10

What are class 3 anti-arrhythmics?

Answer 10

Potassium channel blockers

Question 11

Give an example of a class 3 anti-arrhythmics

Answer 11

Amiodarone

Sotalol

Question 12

What is the action of class 3 anti-arrhythmics? (5)

Answer 12

Delays repolarisation 
Increases duration of AP
Prolongs phase 3 
Prolongs refractory period 
Decreases HR

Question 13

What type of drug are class 4 anti-arrhythmics?

Answer 13

Calcium channel blockers

Question 14

What is the action of class 4 anti-arrhythmics?

Answer 14

Blocks L-type Ca2+ channels
Slows conduction through AVN
Prolongs phase 2
Decreases HR

Question 15

What are calcium channel blockers used for a lot? Why?

Answer 15

SVT

They block re-entry mechanism by slowing down conduction through AVN

Question 16

Give an example of a Calcium channel blocker

Answer 16

Verapamil (oral/IV)

Diltiazem (oral)

Question 17

What is another use (aside from arrhythmias) of class 4 anti-arrhythmics?

Answer 17

Hypertension

Question 18

Name the drug used for AF (not in any classes of anti-arrhythmics)

Answer 18

Digoxin

Question 19

What is the action of digoxin?

Answer 19

Slows HR
Decreases conduction through AVN
Inhibits Na/K/ATPase - no RMP
Indirectly stimulates Vagus nerve - reduces SAN and conduction of AVN

Question 20

Name some common side effects of anti-arrhythmics

Answer 20

Proarrhythmic
Dizziness
GI disturbances

Question 21

Give a drug used to treat AF

Answer 21

Rhythm control:
Sotalol (3)
Flecainide (1) [w/ bisoprolol (2) for Atrial flutter]
Amiodarone (3)

Rate control:
Bisoprolol (2)
Verapamil (4)
Diltiazem (4) +/- digoxin

Question 22

Give examples of drugs used to treat VT

Answer 22

Metoprolol (2)
Lignocaine (1)
Amiodarone (3)

Question 23

Give examples of drugs used to treat Wolff-Parkinson-white syndrome

Answer 23

Amiodarone (3) (not for long term)

Flecainide (1)

Question 24

Give examples of drugs for re-entrant SVT

Answer 24

Chronic (oral):
Bisoprolol (2) and verapamil (4)
Sotalol (3)
Amiodarone (3) - last choice due to side effects

Acute (IV):
Adenosine (blocks AVN)
Verapamil (4)
Flecainide (1)

Question 25

Give examples of drugs used for ectopic beats

Answer 25

Flecainide (1) - as long as there is no structural or IHD
Sotalol (3)
Amiodarone (3)
Bisoprolol (2)

Question 26

Give examples of drugs used for sinus tachycardia

Answer 26

Bisoprolol (2)
Verapamil (4)
Ivabradine