Antiarrhythmic drugs

Question 1

What action do calcium channel blockers have on the heart?

Answer 1

Slows conduction through the AV node

For arrhythmias originating above the AV node

Question 2

What is the hierarchy of pacemaker cells?

Answer 2

SAN
AVN
Bundle of his
purkynje fibres

Question 3

What is the main sodium channel blocker that acts ONLY on ventricular action potentials?

Answer 3

Lidocaine

Question 4

What are the main sodium channel blockers that acts on atrial and ventricular action potentials?

Answer 4

Procainamide

Quinidine

Question 5

What can cause an arrhythmia?

Answer 5

Structural/ electrical remodelling
Haemodynamics
Endocrine issues

Question 6

What is the definition of automaticity?

Answer 6

Spontaneous rhythmic depolarisation of cells in the conduction system

Question 7

What are afterdepolarisations?

Answer 7

Oscillations during repolarisation

Can trigger sibsequent action potentials

Question 8

Where do supraventricular arrhythmias originate?

Answer 8

In SAN, atrial myocardium or AVN

Question 9

Where do ventricular arrhythmias originate?

Answer 9

Bundle of His
Purkynje system
Ventricular myocardium

Question 10

What are class I antiarrhythmic drugs?

Answer 10

Sodium channel blockers

Question 11

What are class II antiarrhythmic drugs?

Answer 11

Beta blockers

Question 12

What are class III antiarrhythmic drugs?

Answer 12

Potassium channel blockers

Question 13

What are class IV antiarrhythmic drugs?

Answer 13

Calcium channel blockers

Question 14

What are the 3 main Na channel blockers?

Answer 14

Lidocaine
Procainamide
Quinidine

Question 15

What is the main beta blocker?

Answer 15

Atenolol

Question 16

What are the main potassium channel blockers?

Answer 16

Sotalol

Amiodarone

Question 17

What is the main calcium channel blocker?

Answer 17

Diltiazem

Question 18

What is quinidine used for?

Answer 18

Horses with atrial fibrillation

Question 19

What is procainamide used for?

Answer 19

Supra/ventricular arrhythmias in small animals

Question 20

What is lidocaine used for?

Answer 20

Life threatening ventricular arrhythmias

Question 21

What do beta blockers do?

Answer 21

Reduce HR - slow conduction
Decrease heart contraction
Reduce spontaneous depolarization

Question 22

What arrhythmia are beta blockers used for?

Answer 22

Arrhythmias mediated by sympathetic tone

Question 23

What shouldnt you do/use beta blockers for?

Answer 23

Dont use in heart failure

Slowly wean

Question 24

What do potassium channel blockers do?

Answer 24

Prolong refractory period and action potential duration

Suppress tachyarrhythmias

Question 25

What are potassium channel blockers used for?

Answer 25

Supra/ventricular arrhythmias

Question 26

What do calcium channel blockers do?

Answer 26

Reduce automaticity, slow AVN conduction, prolong refractory period

Question 27

What are calcium channel blockers used for?

Answer 27

Supraventricular tachyarrhythmias eg. atrial fibrillation, atrial tachycardia

Question 28

What is digoxin?

Answer 28

A parasympathomimetic Decreases SAN firing Slows AVN conduction

Question 29

What is digoxin used for?

Answer 29

Atrial fibrillation