Arrhythmia Pharmocology

Question 1

Explain the actions of class 1, 1a, 1b & 1c antiarrhythmic

Answer 1

Class 1 - Sodium channel blocker
Class 1a - increase duration AP (L & R curve shifts R)
Class 1b - decrease duration AP (R curve shifts L)
Class 1c - decrease depolarization speed (L curve shifts R)

Question 2

Explain actions of a class 2 antiarrhythmic

Answer 2

Beta Blocker (E.g. Metoprolol)

Question 3

Explain actions of a class 3 antiarrhythmic

Answer 3

Potassium channel blockers (E.g. Amiodarone)

Question 4

Explain actions of a class 4 antiarrhythmic

Answer 4

Calcium channel blockers (decrease AV node speed). E.g. Verapamil