Quiz 12 - Cardiovascular Emergencies / Arrhythmias

Question 1

It is MOST important to evaluate a cardiac arrhythmia in the context of the:

A. patient’s heart rate.

B. width of the QRS complex.

C. patient’s overall condition.

D. patient’s medical history.

Answer 1

C. patient’s overall condition.

Question 2

Bombardment of the AV node by more than one impulse, potentially blocking the pathway for one impulse and allowing the other impulse to stimulate cardiac cells that have already depolarized, is called:

A. ectopy.

B. reentry.

C. excitability.

D. fusion.

Answer 2

B. reentry

Question 3

The PR interval should be no shorter than ____ seconds and no longer than ____ seconds in duration.

A. 0.18, 2.0

B. 0.14, 0.30

C. 0.12, 0.20

D. 0.16, 0.40

Answer 3

C. 0.12, 0.20

Question 4

Junctional escape rhythms are CONSISTENTLY characterized by:

A. QRS complexes greater than 0.12 seconds.

B. inverted P waves before the QRS complex.

C. an absence of P waves.

D. a ventricular rate of 40 to 60 beats/min.

Answer 4

D. a ventricular rate of 40 to 60 beats/min.

Question 5

An electrical wave moving in the direction of a positive electrode will:

A. manifest with narrow QRS complexes.

B. cause a positive deflection on the ECG.

C. cause a negative deflection on the ECG.

D. produce a significant amount of artifact.

Answer 5

B. cause a positive deflection on the ECG.

Question 6

A prolonged PR interval:

A. indicates an abnormal delay at the AV node.

B. is greater than 120 milliseconds.

C. is a sign of rapid atrial depolarization.

D. indicates that the AV node was bypassed.

Answer 6

A. indicates an abnormal delay at the AV node.

Question 7

The MOST immediate forms of reperfusion therapy for an injured myocardium are:

A. supplemental oxygen and an infusion of nitroglycerin.

B. angioplasty and coronary artery bypass grafting.

C. fibrinolytics and percutaneous coronary intervention.

D. high-dose aspirin and high-flow supplemental oxygen.

Answer 7

C. fibrinolytics and percutaneous coronary intervention.

Question 8

In order to call a cardiac rhythm “paroxysmal” supraventricular tachycardia, you would have to:

A. confirm the pacemaker origin with a 12-lead ECG.

B. observe a consistent heart rate greater than 150 beats/min.

C. ask the patient when he or she began feeling palpitations.

D. witness its onset and/or spontaneous termination.

Answer 8

D. witness its onset and/or spontaneous termination.

Question 9

Q waves are considered abnormal or pathologic if they are:

A. greater than 0.02 seconds wide and consistently precede the R wave.

B. more than one third the overall height of the QRS complex in lead II.

C. present in a patient who is experiencing chest pressure or discomfort.

D. not visible in leads I or II when the QRS gain sensitivity is increased.

Answer 9

B. more than one third the overall height of the QRS complex in lead II.

Question 10

On the ECG graph paper, 6 seconds is represented by how many large boxes?

A. 40

B. 30

C. 20

D. 50

Answer 10

B. 30

Question 11

Damage to the cardiac electrical conduction system caused by an acute myocardial infarction MOST commonly results in:

A. acute bundle branch block.

B. severe tachycardia.

C. bradycardia or heart block.

D. ventricular dysrhythmias.

Answer 11

C. bradycardia or heart block.

Question 12

A second-degree heart block, Mobitz type I, occurs when:

A. each successive impulse is progressively delayed, until one impulse is blocked from entering the ventricles.

B. the PR interval progressively grows narrower, until there is a P wave that is not followed by a QRS complex.

C. every other impulse generated by the SA node is blocked at the AV node and does not depolarize the ventricles.

D. more than one successive impulse from the SA node is blocked at the AV node and is not allowed to enter the ventricles

Answer 12

A. each successive impulse is progressively delayed, until one impulse is blocked from entering the ventricles.

Question 13

A regular rhythm with inverted P waves before each QRS complex, a ventricular rate of 70 beats/min, narrow QRS complexes, and a PR interval of 0.16 seconds should be interpreted as a(n):

A. supraventricular tachycardia.

B. accelerated junctional rhythm.

C. junctional escape rhythm.

D. ectopic atrial rhythm.

Answer 13

B. accelerated junctional rhythm.

Question 14

Normally, the ST segment should be:

A. elevated by no more than 1 mm.

B. depressed by no more than 2 mm.

C. at the level of the isoelectric line.

D. invisible on a normal ECG tracing.

Answer 14

C. at the level of the isoelectric line.

Question 15

Stimulation of the parasympathetic nervous system:

A. completely blocks the AV node, preventing ventricular depolarization.

B. causes a decrease in the production of epinephrine and norepinephrine.

C. is characterized by a large P wave and a PR interval that is shorter than normal.

D. slows SA nodal discharge and decreases conduction through the AV node.

Answer 15

D. slows SA nodal discharge and decreases conduction through the AV node.

Question 16

A wandering atrial pacemaker:

A. may have variable PR intervals.

B. is generally faster than 100 beats/min.

C. is generally treated with atropine.

D. has consistent P-wave shapes.

Answer 16

A. may have variable PR intervals.

Question 17

The MOST common cause of cardiac arrest in adult patients is:

A. a dysrhythmia.

B. respiratory failure.

C. electrocution.

D. acute myocardial infarction

Answer 17

A. a dysrhythmia.

Question 18

The 6-second method for calculating the rate of a cardiac rhythm:

A. is an accurate method for calculating the heart rate if the cardiac rhythm is grossly irregular and very fast.

B. takes longer than other methods of calculating the rate and is thus impractical to use with critical patients.

C. will yield an estimated heart rate that is typically within 2 to 3 beats per minute of the actual heart rate.

D. involves counting the number of QRS complexes in a 6-second strip and multiplying that number by 10.

Answer 18

D. involves counting the number of QRS complexes in a 6-second strip and multiplying that number by 10.

Question 19

A normal QT interval lasts:

A. 0.36 to 0.44 seconds.

B. 0.15 to 0.25 seconds.

C. 0.38 to 0.48 seconds.

D. 0.30 to 0.40 seconds.

Answer 19

A. 0.36 to 0.44 seconds.

Question 20

The brief pause between the P wave and QRS complex represents:

A. full dispersal of electricity throughout both atria.

B. the period of time when the atria are repolarizing.

C. depolarization of the inferior part of the atria.

D. a momentary conduction delay at the AV junction.

Answer 20

D. a momentary conduction delay at the AV junction.

Question 21

On the ECG graph paper, amplitude is measured in _____________ and width is measure in ____________.

A. milliseconds, millimeters

B. centimeters, seconds

C. millimeters, milliseconds

D. seconds, centimeters

Answer 21

C. millimeters, milliseconds

Question 22

A wide QRS complex that is preceded by a normal P wave indicates:

A. a delay in conduction at the AV junction.

B. rapid conduction through the ventricles.

C. an abnormality in ventricular conduction.

D. that the rhythm is ventricular in origin.

Answer 22

C. an abnormality in ventricular conduction.

Question 23

According to the Einthoven triangle, lead II is assessed by placing the:

A. negative lead on the left arm and the positive lead on the left leg.

B. positive lead on the left arm and the negative lead on the right arm.

C. positive lead on the left leg and the negative lead on the right arm.

D. negative lead on the right arm and the positive lead on the left leg.

Answer 23

D. negative lead on the right arm and the positive lead on the left leg.

Question 24

The P wave represents:

A. contraction of the atria.

B. a delay at the AV node.

C. atrial depolarization.

D. SA nodal discharge.

Answer 24

C. atrial depolarization.

Question 25

Which of the following statements regarding sinus bradycardia is correct?

A. Sinus bradycardia is caused by decreased vagal tone in most patients.

B. Treatment focuses on the patient’s tolerance to the bradycardia.

C. Sinus bradycardia often requires multiple doses of atropine to correct it.

D. Symptomatic bradycardia is often caused by a decreased atrial rate.

Answer 25

B. Treatment focuses on the patient’s tolerance to the bradycardia.