class 1a

prolong ap duration

binds to na channels is use dependent manner

useful for: VENTRICULAR ARRHYTHMIAS, PAROXYSMAL RECURRANT ATRIAL FIBRILLATION.

CLASS 1B

decreased ap duration

supress automaticity

useful for: MYOCARDIAL INFARCTION, VENTRICULAR TACHYCARDIAS

minimal change in ap duration

supresses automaticity

increased refractory period

usefor: WPW SYNDROME, RECURRANT TACHYARRYTHMIAS

decreased cardiac contractility = contraindicated immediately post MI

class II antiarrythmic agent

beta blocker

supress automaticity

shorter ap andf longer ref period

decreased conduction in both nodes

useful for: SVT, POST MI

class III antiarryhthmic agent = k channel blocker

prolonged ref period and ap

useful for: WPW SYNDROME, VENTRICULAR TACHYCARDIAS, ATRIAL FIBRILLATION

class IV antiarryhthmic agent = ca channel blocker

block av node

reduce o2 demand and cardiac work

useful for: PREVENTION OF PAROXYSMAL SVT, REDUCE VENTRICULAR RATE IN ATRIAL FIBRILLATION

vagal stimulant

supress av conduction

decrease ventricular rate

useful for: SVT, ATRIAL FIB/FLUTTER