Antiarrhythmic classifications

Question 1

Class I

Answer 1

block sodium channels

Question 2

Class II

Answer 2

reduce adrenergic activity of the heart

Question 3

Class III

Answer 3

K+ channel inhibitors

Question 4

Class IV

Answer 4

CCBs

Question 5

Misc

Answer 5

Adenosin
Digoxin
Magnesium
Potassium

Question 6

Class IA drugs

Answer 6

Quinidine

Procainamide

Question 7

Quinidine

Answer 7

Class IA

Question 8

Procainamide

Answer 8

Class IA

Question 9

Class IB drug

Answer 9

Lidocaine

Question 10

Lidocaine

Answer 10

Class IB

Question 11

Flecainide

Answer 11

Class IC

Question 12

Class IC drug

Answer 12

flecainide

Question 13

Quinidine MOA

Answer 13

referentially block open/activated sodium channels, lengthening duration of action potential

Question 14

Blocking activated sodium channels

Answer 14

lengthens the duration of action potential

Question 15

Procainamide MOA

Answer 15

referentially block open/activated sodium channels, lengthening duration of action potential

Question 16

Lidocaine MOA

Answer 16

block inactivated sodium channels, shortening duration of action potential

Question 17

Flecainide MOA

Answer 17

bind all sodium channels, no effect on duration of action potential

Question 18

Binding all sodium channels…

Answer 18

has no effect on duration of action potential

Question 19

blocking inactivated sodium channels…

Answer 19

shortens duration of action potential

Question 20

K+ channel inhibition….

Answer 20

increases effective refractory period

Question 21

Amiodarone

Answer 21

K+ channel inhibitor

Question 22

Sotalol

Answer 22

K+ channel inhibitor (and non-selective B blocker)

Question 23

CCBs MOA

Answer 23

Block slow L-type cardiac Ca++ channels

Question 24

Propranolol

Answer 24

non-specific B blocker

Question 25

Acebutolol

Answer 25

B1 specific B blocker

Question 26

Esmolol

Answer 26

B1 specific B blocker

Question 27

Amiodarone has a bunch of other effects:

Answer 27

``` Blocks Na+ channels (class I) B-blocker (class II) Some Ca+ channel blocking (Class IV) Alpha blocker ```

Question 28

Block slow L-type cardiac Ca++ channels...

Answer 28

decreases HR and contractility

Question 29

Adenosine MOA

Answer 29

Enhanced K+ conduction and inhibition of cAMP-induced Ca++ influx→ hyperpolarization→ heart “resets”

Question 30

Potassium MOA

Answer 30

membrane potential stabilizing action by increased K+ permeability: hyperpolarizing

Question 31

Hyperpolarizing the myocyte effects:

Answer 31

→ decreased action potential duration → decreased conduction → decreased pacemaker rate → decreased pacemaker arrhythmogenesis