Arrhythmias Therapy Flashcards
What is class I of the Vaughan-Williams antiarrhythmic drug classification?
Sodium channel blockers
What is the mechanism of action of sodium channel blockers?
Membrane stabilising agents, act principally by suppressing excitability and slowing conduction in atrial or ventricular muscle
What are the class Ia drugs? How do they work?
Quinidine
Disopyrmaide
Block sodium channels and prolong AP
What are the class Ib drugs? How do they work?
Lidocaine
Mexiletine
Block sodium channels and shorten AP
What are the class Ic drugs? How do they work?
Flecanide
Propafenone
Block sodium channels, no effect on AP
What is class II of the Vaughan-Williams antiarrhythmic drug classification?
Beta blockers
What are the class II drugs?
Atenolol
Bisoprolol
Metoprolol
L-sotalol
Beta-adrenoceptor antagonists
What are the class III Vaughan-Williams antiarrhythmic drugs?
Amiodarone
D-sotalol
What is the mechanism of action of the class III drugs?
Main effect is to prolong the AP - act by prolonging the plateau phase of the AP, thus lengthening the refractory period
What is class IV of the Vaughan-Williams antiarrhythmic drug classification?
Slow calcium channel blockers
What are the class IV drugs?
Verapamil
Diltiazem
What is the mechanism of action of the class IV drugs?
Block the slow calcium channel which is particularly important for impulse generation and conduction in atrial and nodal tissue
