Cardiac Antiarrhythmics - QUIZ

Question 1

Which of the following describe action potential?
Select ALL that apply.
a) Voltage change in action potential is described as polarized and depolarized state
b) Depends upon active ion movement
c) Divided into phases 0 through 6
d) Action potential represents voltage change during activation and relaxation of strictly conducting tissues such as the SA node

Answer 1

a) Voltage change in action potential is described as polarized and depolarized state

Question 2

Which of the following describe the mechanism of action for Class Ia antiarrhythmics?

a) Weak sodium channel blockade with potassium channel opening effects leading to shortening of the action potential duration
b) Are strictly sodium channel blockers with no potassium channel effects and do not affect action potential duration
c) Moderate sodium channel blockade with some potassium channel blockade leading to prolongation of the action potential duration

Answer 2

c) Moderate sodium channel blockade with some potassium channel blockade leading to prolongation of the action potential duration

Question 3

Class I antiarrhythmics not only have class specific adverse effects but agent specific adverse effects as well. True or False?

Answer 3

True

Question 4

Which of the following Class I antiarrhythmic agents has CNS toxicity effects?

a) Quinidine
b) Lidocaine
c) Procainamide
d) Flecainide

Answer 4

b) Lidocaine

Question 5

Class III antiarrhythmics mainly act on potassium channels. Potassium ion movement out of the cell governs which of the following?

a) Membrane voltage potential
b) Action potential voltage
c) Refractory period duration
d) Action potential duration

Answer 5

d) Action potential duration

Question 6

Which of the following is the main adverse effect of Potassium channel blockade with Class III agents:

a) QT prolongation
b) AV blockade
c) Widening of QRS duration
d) Negative Inotropy

Answer 6

a) QT prolongation

Question 7

Which of the following is true regarding class II agents:
Select ALL that apply.
a) Class II agents are non-competitive beta antagonists
b) Class II agents competitively bind with beta adrenoceptor sites
c) Class II agents work on the kidney to decreasing renin secretion
d) Class II agents strictly reduce heart rate and contractility
e) Class II agents can be selective, non-selective or non-selective mixed agents
f) Class II agents are strictly selective agents

Answer 7

b) Class II agents competitively bind with beta adrenoceptor sites
c) Class II agents work on the kidney to decreasing renin secretion
e) Class II agents can be selective, non-selective or non-selective mixed agents

Question 8

Amiodarone can increase the effect of Heparin as well as the serum concentrations of Digoxin, Procainamide, and other medications. True or False?

Answer 8

False

Question 9

Class IVa agents such as Diltiazem have relatively localized nodal calcium ion channels due to:

a) Phase O of SA node action potential is Calcium dependent
b) Phase 1 of AV and SA node action potential is Calcium dependent
c) Phase 0 of AV and SA node action potential is Calcium dependent
d) Phase 1 of AV node action potential is Calcium dependent

Answer 9

c) Phase 0 of AV and SA node action potential is Calcium dependent

Question 10

Class IVb agents are calcium channel blockers through indirect action via:

a) Sodium ion channel blocking
b) Potassium ion channel opening
c) Sodium ion channel opening
d) Potassium ion channel blocking

Answer 10

b) Potassium ion channel opening

Question 11

Class V antiarrhythmic medications account for:

a) Medications that do not fit into the other categories
b) Anticholinergics
c) Cardiac glycosides
d) Sodium potassium pump inhibitors

Answer 11

a) Medications that do not fit into the other categories