1. Antiarrhythmic Drugs-Overview
Dr. Fahad Azam
Shifa College of Medicine

2. Classification of antiarrhythmic drugs
Classification of drugs Mechanism of action
IA Na+ channel blocker
Qunidine, Procainamide
IB Na+ channel blocker
Lidocaine, Mexiletine
IC Na+ channel blocker
Flecainide, Propafenone
II Beta receptor blocker
Propanalol, Metoprolol
III K+ channel blocker
Amiodarone, Sotalol,
IV Ca+ channel blocker
Verapamil, Diltiazem, Nifedipine

3. Conduction Pathways and Velocity of Conduction
• Conduction Pathway:
SA node  atrial muscle  AV node  Purkinjee fibers  Ven. Muscle
delay
• Velocity:
– Fast conducting fiber:
• Purkinjee cell, Ventricular muscle, Atrial muscle
– Slow conducting fiber:
• AV node, SA node

4. Classification Mechanism of action
of drugs
IA Na+ channel blocker
Qunidine,
Procainamide
IB Na+ channel blocker
Lidocaine, Mexiletine
IC Na+ channel blocker
Flecainide,
Propafenone
II Beta receptor
blocker
Propanalol,
Metoprolol
III K+ channel blocker
Amiodarone, Sotalol,
IV Ca+ channel blocker
Verapamil, Diltiazem,
Nifedipine

5. Intracellular Extracellular
Na Leak
Na Pump
K Pump
K Diffusion