Arrhythmia Flashcards
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
Ia- disopyramide Ib- lignocaine Ic- flecainide II- metoprolol III- amiodarone IV- verapamil
What pneumonic can be used to remember the drug names?
Drinking Lots oF Mango Arrhythmias Vanish
How can you remember the target of vaughn williams classification?
I- Na has 3, SOextra
II- lol
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?
Amiodarone
Sotalol
classes IA, IC
Describe the action of adenosine in SVTs
opens GIRK channels in AV node
suppresses conduction
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
Post MI
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
paroxysmal AF
negative inotropic action and may tricker ventricular arrhythmias
