Antirrhythmic Drug Classes

Question 1

Class Ia Agents

Answer 1

Intermediate Na+ channel blockers - Disopyramide quinidine, procainamide

Question 2

Class Ia effects

Answer 2

↓ Conduction velocity; ↑ refractory period
↑ QRS complex and ↑ QT interval

Question 3

Class Ib agents

Answer 3

Fast Na+ channel blockers -Lidocaine, mexiletine, phenytoin

Question 4

Class Ib effects

Answer 4

↓ Conduction velocity; ↓↑ refractory period
↓ QT interval

Question 5

Class Ic agents

Answer 5

Slow Na+ channel blockers -Flecainide, propafenone

Question 6

Class Ic effects

Answer 6

↓↓↓ Conduction velocity; Ø refractory period
↑ QRS complex

Question 7

Class II agents

Answer 7

β-Blockers - Metoprolol, esmolol, atenolol

Question 8

Class II effect

Answer 8

↓ Conduction velocity; ↑ refractory period
↓ HR and ↑ PR interval

Question 9

Class III agents

Answer 9

K+ channel blockers - Amiodarone,
dronedarone, sotalol,dofetilide, ibutilide

Question 10

Class III effects

Answer 10

Ø Conduction velocity;
↑↑↑ refractory period
↑ QT interval

Question 11

Class IV agents

Answer 11

Ca2+ channel blockers -Diltiazem, verapamil

Question 12

Class IV effects

Answer 12

↓ Conduction velocity;↑ refractory period
↓ HR and ↑ PR interval