16 - ANTIARRHYTHMICS

Item Number: 11423 correct answer: 1 category: Antiarrhythmics

1. Properties of the class IA antiarrhythmics include

A. reduce automaticity of his-Purkinje fibers

B. decrease the rate of rise and amplitude of phase 0 depolarization

C. prolong P-R and Q-T intervals

D. facilitate inward sodium conductance during rapid depolarization

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11432 correct answer: 4 category: Antiarrhythmics

2. Which of the following antiarrhythmics may worsen angina symptoms by

increasing myocardial oxygen requirements?

A. lidocaine

B. verapamil

C. propranolol

D. disopyramide

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11433 correct answer: 4 category: Antiarrhythmics

3. Cinchonism is a dose-related adverse reaction associated with which of the

following antiarrhythmics?

A. tocainide

B. procainamide

C. disopyramide

D. quinidine

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11447 correct answer: 4 category: Antiarrhythmics

4. Addition of propranolol to the drug regimen of a patient receiving lidocaine

for premature ventricular contractions after a myocardial infarction results

in:

A. increased likelihood of breakthrough PVCs

B. displacement of protein-bound lidocaine

C. reduced renal clearance of lidocaine

D. increased likelihood of lidocaine toxicity

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11448 correct answer: 1 category: Antiarrhythmics

5. Electrophysiologic properties possessed by lidocaine include:

A. reduction of effective refractory period in normal his-Purkinje

fibers

B. prolonged effective refractory period in ischemic his-Purkinje

fibers

C. shortened Q-T interval

D. prolonged P-R interval

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11464 correct answer: 5 category: Antiarrhythmics

6. Which of the following are classified as IB antiarrhythmics?

A. lidocaine

B. phenytoin

C. tocainide

D. mexiletine

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11466 correct answer: 1 category: Antiarrhythmics

7. In treating supraventricular arrhythmias, which of the following reduces

ventricular response primarily by increasing the effective refractory period

of the A-V node?

A. propranolol

B. digoxin

C. verapamil

D. tocainide

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11474 correct answer: 1 category: Antiarrhythmics

8. Potential side effects associated with amiodarone therapy include:

A. pneumonitis

B. pseudocyanosis

C. photosensitivity

D. parotiditis

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11475 correct answer: 3 category: Antiarrhythmics

9. Class IC antiarrhythmics possess which of the following electrophysiologic

properties?

A. markedly prolong repolarization

B. markedly depress phase 0 depolarization

C. inhibit calcium entry during plateau portion of action potential

D. inhibit sodium entry during phase 0 depolarization

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 11476 correct answer: 1 category: Antiarrhythmics

10. Adverse effects associated with disopyramide therapy include:

A. urinary retention

B. constipation

C. blurred vision

D. lupus syndrome

1. A,B,C

2. A,C

3. B,D

4. D only

5. All are correct

Item Number: 289 correct answer: 5 category: Antiarrhythmics

11. Antiarrhythmic drugs can be separated into four groups, types I to IV. All of

the following are type I antiarrhythmic drugs EXCEPT:

1. quinidine

2. lidocaine

3. procainamide

4. phenytoin

5. propranolol

Item Number: 291 correct answer: 5 category: Antiarrhythmics

12. Individual antiarrhythmic agents can alter the surface electrocardiogram.

Characteristics of quinidine include:

1. decreased PR interval

2. increased QRS duration

3. increased QT interval

4. All of the above

5. 2,3

Item Number: 292 correct answer: 5 category: Antiarrhythmics

13. Quinidine toxicity includes all of the following EXCEPT:

1. thrombocytopenia

2. diarrhea

3. cinchonism

4. ventricular fibrillation

5. hypertension

Item Number: 293 correct answer: 1 category: Antiarrhythmics

14. Of the following antiarrhythmic agents, the one which most closely resembles

procainamide with respect to electrophysiologic effects and mechanism of

action is:

1. quinidine

2. lidocaine

3. phenytoin

4. propranolol

5. bretylium

Item Number: 1360 correct answer: 5 category: Antiarrhythmics

15. Bronchiolar constriction is a rare but potentially dangerous side effect of:

1. quinidine

2. lidocaine

3. procainamide

4. phenytoin

5. propranolol

Item Number: 1578 correct answer: 4 category: Antiarrhythmics

16. The effect of different antiarrhythmic agents is best understood by knowing

their predominant actions on cardiac fibers. All of the following general

statements are true EXCEPT:

1. quinidine slows the rate of depolarization of cardiac action potentials

and increases the refractory period

2. lidocaine and phenytoin are class 1 B antiarrhythmic

3. beta-receptor blocking drugs act by reducing the slope of the pacemaker

potential

4. procainamide acts as a specific calcium antagonist

5. bretylium prolongs the action potential and so prolongs the absolute

refractory period

Item Number: 9518 correct answer: 4 category: Antiarrhythmics

17. In the pharmacologic treatment of cardiovascular disorders, quinidine has all

of the following effects EXCEPT:

1. prolongation of the effective refractory period

2. slows conduction velocity

3. reduces spontaneous frequency of discharge of ectopic pacemaker

4. has a positive chronotropic effect

5. produces peripheral vasodilation in large doses

Item Number: 9893 correct answer: 3 category: Antiarrhythmics

18. Which of the following medications is contraindicated in a patient with

untreated complete heart block?

1. atropine

2. prednisone

3. quinidine

4. isoproterenol

5. hydrochlorothiazide

Item Number: 11386 correct answer: 1 category: Antiarrhythmics

19. The therapeutic rationale for the use of quinidine or procainamide includes

their ability to:

1. depress ectopic myocardial automaticity

2. enhance myocardial membrane responsiveness

3. decrease the effective refractory period

4. 1,2

5. 2,3

Item Number: 12788 correct answer: 3 category: Antiarrhythmics

20. All of the following are common side effects of quinidine administration

EXCEPT:

1. diarrhea

2. nausea and vomiting

3. dry mouth

4. tinnitus

5. headache

Item Number: 14457 correct answer: 4 category: Antiarrhythmics

21. 24 hours after an acute myocardial infarction, a 46-year-old male is being

treated with a continuous intravenous drip of an antiarrhythmic drug to

suppress frequent multifocal premature ventricular contractions. He develops

generalized seizure activity. The seizure activity can be most readily

explained by:

1. ventricular tachycardia

2. systemic embolization

3. systemic hypotension

4. lidocaine toxicity

5. ventricular asystole

Item Number: correct answer: 1 category: Antiarrhythmics

22. TRUE statements concerning Vaughan-Williams's Class III antiarrhythmic

drugs include all EXCEPT:

1. encainide, flecainide, and propafenone are in this class

2. bretylium, amiodarone, and sotalol are in this class

3. possess diverse pharmacologic effects but share the capacity to prolong

action potential duration and refractoriness in Purkinje fibers

4. block outflow of potassium during cell repolarization

5. do not alter phase 0 depolarization or resting membrane potential

Questions 23 - 29

Choose the correct answer for the following questions from the list below.

Each answer can be used once, more than once, or not at all.

1. bretylium

2. amiodarone

3. adenosine

4. flecainide

5. lidocaine

Item Number: correct answer: 5 category: Antiarrhythmics

23. In ACLS algorithm, first antiarrhythmic to be administered in the treatment of

ventricular fibrillation refractory to defibrillation and epinephrine.

Item Number: correct answer: 3 category: Antiarrhythmics

24. Drug of choice for paroxysmal supraventricular tachycardia unresponsive to

vagal maneuvers.

Item Number: correct answer: 1 category: Antiarrhythmics

25. Produces transient increase in blood pressure followed by hypotension due to

an initial release of norepinephrine from neurons followed by blockade of

norepinephrine re-uptake.

Item Number: correct answer: 2 category: Antiarrhythmics

26. Contains iodine in molecular structure, is similar to thyroxine, and use is

associated with hyper- or hypothyroidism in 2% - 5% of patients.

Item Number: correct answer: 2 category: Antiarrhythmics

27. Pharmacokinetic properties characterized by very high protein-binding (99.9%),

very large volume of distribution (66 L/kg), and average elimination half-life

of 25 days.

Item Number: correct answer: 4 category: Antiarrhythmics

28. A class IC antiarrhythmic, characterized by high affinity for and slow

dissociation from fast sodium channels

Item Number: correct answer: 5 category: Antiarrhythmics

29. A class IB antiarrhythmic, characterized by rapid association - dissociation

from sodium channels

Item Number: correct answer: 4 category: Antiarrhythmics

30. Correct statements concerning propafenone include all EXCEPT:

1. class IC antiarrhythmic

2. slows actions potential conduction by blocking sodium channels

3. possesses weak beta blocking activity

4. class III antiarrhythmic

5. increases duration of QRS complex

Item Number: correct answer: 1 category: Antiarrhythmics

31. Correct statements concerning sotalol include all EXCEPT:

1. prolongs action potential duration and effective refractory period by

blocking sodium channels.

2. prolongs cell repolarization by blocking potassium channels.

3. produces bradycardia

4. prolongs Q-T interval

5. increases effective refractory period

Questions 32 - 35

Choose the correct answer for the following questions from the list below.

Each answer can be used once, more than once, or not at all.

1. propranolol

2. acebutolol

3. sotalol

4. esmolol

5. butorphanol

Item Number: correct answer: 4 category: Antiarrhythmics

32. Cardioselective beta blocker with a short elimination half-life administered

intravenously only.

Item Number: correct answer: 3 category: Antiarrhythmics

33. Nonselective beta blocker which slows heart rate and also prolongs action

potential duration by blocking transmembrane potassium currents.

Item Number: correct answer: 2 category: Antiarrhythmics

34. Cardioselective beta blocker possessing intrinsic sympathetic activity and

given by oral administration only.

Item Number: correct answer: 1 category: Antiarrhythmics

35. Nonselective beta blocker possessing quinidine-like membrane stabilizing

effects.

Item Number: correct answer: 5 category: Antiarrhythmics

36. FALSE statement concerning use of calcium antagonists as antiarrhythmics:

1. slows inward calcium current thereby decreasing the rate of spontaneous

phase 4 depolarization in Purkinje fibers

2. slows conduction velocity through the atrio-ventricular node and

increases functional refractory period

3. useful for slowing ventricular rate in atrial fibrillation

4. hypotension may be a limiting side effect

5. verapamil, diltiazem, and nifedipine all exert equally effective

antiarrhythmic actions

Item Number: correct answer: 3 category: Antiarrhythmics

37. CORRECT statement concerning the antiarrhythmic drug adenosine:

1. undergoes extensive hepatic metabolism

2. produces coronary vasoconstriction

3. causes frequent but transient post-conversion arrhythmias

4. increases sinus node rate

5. increases atrio-ventricular conduction

Item Number: correct answer: 1 category: Antiarrhythmics

38. True statement concerning adenosine include all EXCEPT:

1. administered sublingually

2. negative chronotrope

3. negative dromotrope

4. negative inotrope

5. may precipitate bronchospasm

Item Number: correct answer: 5 category: Antiarrhythmics

39. FALSE statement concerning adenosine:

1. half-life of 1 - 10 seconds

2. higher doses necessary in patients taking theophylline

3. chest pain and shortness of breath are common but short-lived side

effects

4. indicated for treating paroxysmal supraventricular tachycardia

5. less effective than verapamil for treating paroxysmal supraventricular

tachycardia

Item Number: correct answer: 2 category: Antiarrhythmics

40. Correct statements about epinephrine administration for ventricular

fibrillation include all EXCEPT:

1. 1 mg IV push every 3 - 5 minutes

2. 0.1 mg IV push every 3 - 5 minutes

3. 0.1 mg/kg IV push every 3 - 5 minutes

4. 1 mg IV push followed by 3 mg IV push followed by 5 mg IV push 3 minutes

apart

5. 2.5 mg diluted to a total volume of 10 ml in saline solution via an

endotracheal tube when no IV access is available