Deck 23: Treatment of Cardiac Arrhythmias

Question 1

Which of the following drug categories is NOT used to treat cardiac arrhythmias?

A) sodium channel blockers
B) chloride channel blockers
C) beta blockers
D) calcium channel blockers
E) drugs that prolong cardiac repolarization

Answer 1

chloride channel blockers

Question 2

While attempting to control one type of arrhythmia,antiarrhythmic drugs can exert "proarrhythmic" effects,which are indicated by

A) a delay of 4 to 6 weeks before these drugs become effective
B) common musculoskeletal abnormalities such as skeletal muscle fasciculations
C) their ability to aggravate or initiate other cardiac rhythm abnormalities
D) their ability to aggravate the proton pump in the stomach, resulting in gastric ulcers
E) their ability to increase body temperature and cause fever

Answer 2

their ability to aggravate or initiate other cardiac rhythm abnormalities

Question 3

Calcium channel blockers are useful in treating certain cardiac arrhythmias because they

A) decrease the rate of discharge of the SA node
B) increase conduction velocity through the AV node
C) block the effects of catecholamines (epinephrine, norepinephrine) on cardiac tissues
D) inhibit the ability of sodium to excite cardiac membranes
E) none of the above are true; calcium channel blockers are not used to treat arrhythmias

Answer 3

decrease the rate of discharge of the SA node

Question 4

An antiarrhythmic drug that prolongs the effective refractory period of the cardiac action potential

A) will speed up repolarization of cardiac muscle cells
B) will generally increase heart rate
C) will decrease the time interval between cardiac action potentials
D) all the above are true
E) none of the above are true

Question 5

An antiarrhythmic drug used to treat bradycardia inadvertently creates tachycardia.The most likely reason is that this drug causes _____ of the ______.

A) inhibition; sinoatrial node
B) excitation; sinoatrial node
C) inhibition; bundle of His
D) excitation; bundle of His
E) inhibition; atrioventricular node

Question 6

Depending on the dose and route of administration,lidocaine and similar drugs can be used as local anesthetics or cardiac antiarrhythmic drugs because these drugs affect the excitability of _____ ion channels.

A) sodium
B) potassium
C) chloride
D) calcium
E) magnesium

Question 7

Beta blockers are effective in treating certain cardiac arrhythmias because they _____ the excitatory effects of ______ on the heart

A) increase; acetylcholine
B) decrease; acetylcholine
C) increase; catecholamines (epinephrine and norepinephrine)
D) decrease; catecholamines (epinephrine and norepinephrine)
E) increase; beta interferons