Anti-Arrhythmics

Question 1

What do Class 1 anti-Arrhythmics act on?

Answer 1

Sodium channels

Question 2

Class 1 AA’s are split according to how they affect the length of action potentials. What are the sub-groups?

Answer 2

1a: lengthens
1b: shortens
1c: stays the same

Question 3

What are examples of 1a AA’s?

Answer 3

Quinidine

Procainamide

Question 4

What effect does 1a have on cardiac activity?

Answer 4

Decreases conduction
Increases refractory period
Increases threshold

Question 5

When is 1a used?

Answer 5

Maintains sinus rhythm in AF

Prevents tachycardia and fibrillation

Question 6

What are ADRs of 1a?

Answer 6

Hypotension
Dizziness, confusion, insomnia
GI

Question 7

What are examples of 1b?

Answer 7

Lidocaine

Phenytoin

Question 8

What effects do 1b have on cardiac activity?

Answer 8

Increased threshold

Decreased phase 0 conduction in fast beating or ischaemic tissue

Question 9

When is 1b used?

Answer 9

Ventricular tachycardia

Question 10

What are ADRs of 1b?

Answer 10

Dizziness

Drowsiness

Question 11

What are the effects of 1c on cardiac activity?

Answer 11

Increases threshold

Increased refractory period

Question 12

When is 1c used?

Answer 12

Supra ventricular arrhythmias

Wolff-Parkinson-White syndrome

Question 13

What are the ADRs of 1c?

Answer 13

Sudden death with chronic use

CNS and GI

Question 14

What are class 2 agents?

Answer 14

Beta blockers

Question 15

What are examples of class 2?

Answer 15

Propanolol

Acebutol

Question 16

When are class 2 agents used?

Answer 16

Tachycardic arrhythmia

Protecting ventricles from high atrial rates

Question 17

What are the ADRs of class 2?

Answer 17

Bronchospasm
Hypotension
Don’t use in partial AV block/ ventricular failure

Question 18

What does class 3 do?

Answer 18

Block potassium channels

Prolong repolarization

Question 19

What are examples of class 3?

Answer 19

Amiodarone

Sotalol

Question 20

What are the cardiac effects of Amiodarone?

Answer 20

Increased refractory period
Increased threshold
Decreased AV conduction

Question 21

What are the uses of Amiodarone?

Answer 21

Effective for most arrhythmias

Question 22

What are the ADRs of Class 3?

Answer 22

Pulmonary fibrosis
Hepatic injury thyroid disease
Increased LDL cholesterol

Question 23

What are the cardiac effects of Sotalol?

Answer 23

Increased refractory tissue

Slow AV conduction

Question 24

What are the uses of Sotalol?

Answer 24

Supra ventricular and ventricular tachycardia

Question 25

What are the ADRs of Sotalol?

Answer 25

Pro arrhythmia
Fatigue
Insomnia

Question 26

What do class 4 agents do?

Answer 26

Calcium channel blocker

Question 27

What are examples of class 4 agents?

Answer 27

Verapamil

Diltiazem

Question 28

What are the cardiac effects of class 4 agents?

Answer 28

Slow AV conduction

Increased refractory period in the AV node

Question 29

When are class 4 agents used?

Answer 29

Supra ventricular tachycardia

Question 30

What are the ADRs of class 4 agents?

Answer 30

Caution with AV block
Caution with hypotension or decreased cardiac output
GI

Question 31

How does adenosine work?

Answer 31

Binds to A1 receptors and activates potassium currents in SA node
Hyperpolarization
Decreases heart rate
Decreases calcium currents

Question 32

How does Digoxin work?

Answer 32

Cardiac glycosides 
Enhances vagal activity 
  Increases potassium currents, decreases calcium currents 
  Increases refractory period 
Slows AV conduction and slows heart rate

Question 33

When is Digoxin used?

Answer 33

Atrial fibrillation and flutter

Question 34

What are the cardiac effects of atropine?

Answer 34

Block vagal activity to speed AV conduction and increased heart rate

Question 35

What is atropine used for?

Answer 35

Vagal bradycardia

Question 36

What is magnesium used to treat?

Answer 36

Tachycardia resulting from long QT

Question 37

How can Arrhythmia come about?

Answer 37

Abnormal impulse generation
Abnormal conduction
After-depolarizations
Re-entry