Deck 11: Origin and Clinical Aspects of Sinus Node Dysrhythmias

Question 1

During normal heart activity, the _______ acts as the primary pacemaker.

A) AV node
B) atria
C) Purkinje fibers
D) SA node

Answer 1

SA node

Question 2

Sinus rhythms include all the following except:

A) Sinus tachycardia.
B) Sinus dysrhythmia.
C) Atrial tachycardia.
D) Sinus pause.

Answer 2

Atrial tachycardia.

Question 3

Characteristics of sinus rhythm include:

A) an irregular rhythm.
B) progressively longer P-R intervals.
C) an inverted P wave which follows each QRS complex.
D) a rate of between 60 and 100 beats per minute.

Answer 3

a rate of between 60 and 100 beats per minute.

Question 4

Cardiac output is defined as ________________.

A) blood pressure x stroke volume
B) peripheral resistance x heart rate
C) heart rate x stroke volume
D) blood pressure plus systole

Question 5

Sinus ____________ is a slow dysrhythmia.

A) dysrhythmia
B) bradycardia
C) tachycardia
D) rhythm

Question 6

Which of the following rhythms may result in hypotension?

A) Sinus tachycardia
B) Sinus bradycardia
C) Sinus dysrhythmia
D) Sinus arrest

Question 7

Sinus bradycardia:

A) often occurs naturally as the body's way to conserve energy.
B) arises from the AV junction.
C) results from sympathetic nervous system stimulation.
D) is caused by failure of the SA node.

Question 8

Characteristics seen with sinus bradycardia include:

A) there are two P waves preceding each QRS complex.
B) the heart rate is between 60 and 100 BPM.
C) the rhythm is regular.
D) the QT intervals are commonly shorter than normal.

Question 9

Sinus _______ is considered a diagnostic indicator of a seriously ill child because it denotes significant hypoxia and inadequate perfusion.

A) tachycardia
B) dysrhythmia
C) arrest
D) bradycardia

Question 10

Treatment of symptomatic sinus bradycardia includes:

A) administering atropine.
B) administering beta blockers.
C) treating the underlying cause.
D) defibrillation

Question 11

Sinus tachycardia

A) results in decreased cardiac output.
B) arises from the SA node.
C) is caused by parasympathetic nervous system stimulation.
D) leads to improved myocardial oxygenation.

Question 12

Characteristics seen with sinus tachycardia include:

A) there is one P wave preceding each QRS complex.
B) the heart rate is between 100 and 160 BPM.
C) the QT intervals are commonly shorter than normal.
D) All of these.

Question 13

Treatment of sinus tachycardia includes:

A) administering atropine.
B) administering beta blockers.
C) treating the underlying cause.
D) defibrillation

Question 14

Which of the following dysrhythmias has a heart rate that seems to speed up and slow down in a cyclical manner?

A) sinus bradycardia
B) sinus rhythm
C) sinus tachycardia
D) sinus dysrhythmia

Question 15

Sinus dysrhythmia is caused by:

A) blockage of the AV node.
B) failure of the heart's primary pacemaker.
C) increased excitability of the heart muscle.
D) inhibition of parasympathetic activity.

Question 16

Sinus dysrhythmia typically has a rate of _______ beats per minute.

A) less than 80
B) 20 to 40
C) 40 to 60
D) 60 to 100

Question 17

Sinus dysrhythmia typically has:

A) one P wave preceding each QRS complex.
B) wide and bizarre looking QRS complexes.
C) longer than normal QT intervals.
D) PR intervals of greater than 0.20 seconds in duration.

Question 18

Treatment of sinus dysrhythmia:

A) includes administering atropine.
B) requires administering beta blockers.
C) is unnecessary provided the patient is asymptomatic.
D) includes pacing.

Question 19

Sinus arrest is caused by:

A) blockage of the AV node.
B) a transient failure of the SA node to initiate a heart beat.
C) increased excitability of the heart muscle.
D) a rapid firing of the atria

Question 20

Characteristics of sinus arrest include:

A) inverted P waves.
B) a regularly irregular rhythm.
C) a heart rate of 60 to 100 beats per minute.
D) a PR interval of greater than 0.20 seconds in duration.

Question 21

Treatment of sinus arrest:

A) includes administering epinephrine.
B) requires administering beta blockers.
C) includes pacing.
D) is unnecessary provided the patient is asymptomatic.

Question 22

Sinoatrial exit block:

A) occurs when the SA node fires but conduction to the AV node is delayed or blocked
B) is caused by parasympathetic nervous system stimulation.
C) commonly produces hypotension.
D) is extremely common.

Question 23

The characteristic that helps you differentiate sinus dysrhythmia from the other dysrhythmias that arise from the SA node is:

A) a rate that is between 60 and 100 beats per minute.
B) the presence of one normal P wave preceding each QRS complex.
C) a patterned irregularity to the rhythm.
D) QRS complexes which are less than 0.12 seconds in duration

Question 24

A cause of sinus bradycardia is:

A) changes in intrathoracic pressure.
B) anterior wall myocardial infarction that involves the right coronary artery.
C) excessive caffeine use.
D) sympathomimetic drugs such as epinephrine, isoproterenol or dopamine.

Question 25

Sinus tachycardia may be caused by:

A) an underlying illness such as hypovolemia or respiratory distress.
B) excessive parasympathetic nervous system stimulation.
C) carotid sinus massage, vomiting or Valsalva's maneuver.
D) severe damage to the SA node

Question 26

Your patient is experiencing chest pain and has a heart rate of 132 beats per minute. You attach the ECG monitor to see a fast, regular rhythm with a tall upright P wave that precedes each QRS complex. The QRS complexes are 0.10 seconds in duration. This patient is experiencing:

A) sinus tachycardia
B) sick sinus syndrome
C) sinus dysrhythmia
D) sinus rhythm

Question 27

Stimulation of the vagus nerve increases the firing rate of the SA node while stimulation of the sympathetic system decreases it.

Question 28

Sick sinus syndrome is a group of abnormal rhythms that occur with malfunction of the SA node.

Question 29

Tachycardias that occur with sick sinus syndrome are characterized by a long pause after the tachycardia.

Question 30

In sinus arrest the heart rate increases during inspiration and decreases during expiration.