Anti-Arrhythmic Drugs

Question 0

What do class I drugs do?

Answer 0

Block Na+ channels

Question 1

What are the two goals of anti-arrhythmic drugs?

Answer 1

1. Reduce pacemaker activity

2. Modify conduction/refractoriness

Question 2

What do class II drugs do?

Answer 2

Beta-Adrenergic receptor blockers (blocks sympathetic response)

Question 3

What do class III drugs do?

Answer 3

Potassium channel blocking (prolongs refractory period)

Question 4

What do Class IV drugs do?

Answer 4

Block Ca channels

Question 5

Specifically which channel and phase of the cardiac cycle do the Class I drugs block?

Answer 5

Fast sodium channel, phase 0 of muscle cell contraction

Question 6

What is the order of Class I drug subclasses in terms of sodium channel blocking potency?

Answer 6

IC>IA>IB

Question 7

What is the order of Class I drug subclasses in terms of ability to increase ERP?

Answer 7

IA>IC>IB

Question 8

What are the three effects Class II antiarrhythmics have on the heart?

Answer 8

Slow heart rate
Slow AV node conduction velocity
Increase AV node refractory period