Antiarrhythmic agents. Classification and clinical application Flashcards
what is electrical cardioversion
application of an electric shock to terminate a tachycardia
• Tachyarrhythmias that are caused by reentry can usually be terminated by
this procedure, whereas arrhythmias due to abnormal automaticity may
simply persist
what is the use of external cardioversion
terminate supraventricular tachycardias or organized ventricular tachycardias.
performed by briefly sedating the patient and then placing two large electrode paddles (or adhesive electrodes) against the chest on either side of the heart. The electric discharge is electronically synchronized to occur at the time of a QRS complex
what is external defib
same equipment as that used or cardioversion
during defibrillation, there is no organized QRS complex on which to synchronize the electric discharge, so it is delivered using the “asynchronous” mode of the device
when are pacemakers used?
chronic Bradycardias
AV block 2 type and av block 3
what are the CLASS 1A drugs and what is it used for
fast sodium channel blockers
prolong the refactor period and action potential
quinidine
adr - proarrythmic potential -prolongation of qt , prostatic hypertrophy dry eyes - muscuranic receptor stopped
used in supra ventricular and ventricular arrhythmia
what are the class 1b drugs
lidocaine and phenytoin
shortens repolarisation
lidocain - iv - drowsiness
phenytoin - hyperplasia of gums
given with bab
phenytoin - hyperplasia of gums
ventricular tachycardia , prevent ventricular fib immediately after myocardial infraction
what are the class 1c drugs ? what are they used for adr
prolong refractiveness
propafenone
adr - proarythmic
used in supra ventricular arrhythmia
what are the class 2 drugs ,what are they used for , adr
beta blockers
propanolol - non selective
metaprolol - b1 selective
in myocardial infraction strop the prevention of paroxysmal atrial fib when sympathetic overeactvity
what are the class 3 drugs and what are they used for / adr
blockers of K+ channels which prolong repolarization
Amiodarone
adr - bradycardia , peripheral phlebitis
long term - thyroid abnormalities ,pulmonary fibrosis , neuropathy
inhibits CYP
Used in Supraventricular & Ventricular arrhythmias
what are the class 4 drugs and what are they used for / adr
blockers of slow Ca++ channel-mediated conduction and refractoriness
verapamil
• Diltiazem
verapamil - constipation
verapamil ONLY Used in supraventricular arrhythmias
in atrial fibrillation what is used and adr
Digoxin
gynecomastia
in sinus tachycardia what is used and adr
Atropine
in supra ventricular tachycardia what drug is used
Adenosine
what is the adverse effect of all antiarrytmic drugs ?
av brach block , bradycardia
