Class 1: Na+ channel blocker
-change the slope of phase 0
-can abolish tachyarrhythmia caused by reentry circuit
Class 2. Beta blocker
reduces heart rate and conduction velocity
can indirectly alter K and Ca conductance
K+ channel blocker
-increased APD or ERP
-delay repolarization
-inhibit reentry tachycardia
Ca++ channel blocker
-slows the rate of rising in phase 4 of SA node
lowers conduction velocity in SA and AV node
Na+ channel blockers
procainamide, lidocaine, propafenone
beta blocker
propanolol
K+ channel blockers
amiodarone, vernakalant
Ca2+ channel blockers
verapamil and diltiazem
blocks potassium channels and prevents repolarization; significantly blocks inactivated sodium channels preventing new AP
Amiodarone MOA?
blocks activated and non-activated L-type calcium channels
Verapamil and Diltiazem MOA?
Vernakalant
-multichannel blocker (potassium, sodium, etc.)
-prolongs atrial effective refractory period; used for atrial fibrillation
-slows AV node conduction
-No change in ventricular refractory period
Propranolol
nonselective B receptor blocker that acts as full antagonist to decrease heart rate
Propafenone
slow dissociative sodium channel blocker
-used for supraventricular arrhythmias
Procainamide
-blocks sodium channels; slows AP upstroke, slows conduction, prolongs QRS
-depresses SA & AV nodes
-Suppresses abnormal ectopic pacemaker activity
Lidocaine
blocks activated and non-activated sodium channels with rapid kinetics