Flashcards in Arrhythmia Deck (17):
Outline the Vaughn Williams Classifications
IA- Voltage-activated Na channel
IB Voltage-activated Na channel
IC Voltage-activated Na channel
II B-adrenorector (antagonists)
III Voltage-activated K channel
IV Voltage-activated Ca channel
Give an example of each class of drug
What pneumonic can be used to remember the drug names?
How can you remember the target of vaughn williams classification?
I- Na has 3, SOextra
III- three lines in k
When do class I anti-arrhythmics bind?
Class I block open state (conducting) and stabilise inactive state, they dissociate in the resting state, therefore if no tachyarrhythmias less binding.
Which anti-arrhythmics would you use for rate control of SVT?
Classes IC, III
Which anti-arrhythmics would you use for rhythm control of SVT?
Adenosine, digoxin, classes II, IV
Which classes would you use for ventricular arrhythmias?
Classes IA, IB, II
Which classes would you use for arrhythmias of the atria and ventricles and AV accessory node pathways?
classes IA, IC
Describe the action of adenosine in SVTs
opens GIRK channels in AV node
Describe the action of digoxin in SVTs
-slows conduction and prolongs refractory period in AV node and bundle of His
used to treat AF
Describe the action of verapamil in SVTs
-slows conduction and prolongs refractory period
AF and AF
may cause heart block
Describe the use of lignocaine in VTs
Describe the action of disopyramide in SVTs and in VTs
>block open channels- use dependant
>disopyramide- orally recurrent ventricular arrhythmias
>procainamide- IV to treat ventricular arrhythmias post MI
Describe the action of flecainide in SVTs and in VTs
negative inotropic action and may tricker ventricular arrhythmias
Describe the action of propranolol in SVTs and in VTs
control SVT and suppress VT