anti-arrhythmic drugs

Question 0

what are the mechanisms underlying dysrhythmias> 4 types

Answer 0

heart block
delayed after depolarisation
re-entry
ectopic pacemaker activity

Question 1

give a general overview of the action potential of the heart myocytes

Answer 1

phase 0 - fast depolarisation - Na influx 
phase 1 - partial repolarisation
phase 2 - plateau - Ca influx
phase 3 - repolarisation - K efflux 
phase 4 - pacemaker potential

Question 2

what are the 5 drug classes for anti-arrhythmic agents?

Answer 2

class 1 - Na channel blocker
class 2: beta blockers/beta adrenergic receptor antagonist 
class 3: k channel blocker
class 4: ca channel blocker
class 5: miscellaneous