Deck 13: Origin and Clinical Aspects of Junctional Dysrhythmias

Question 1

Rhythms that originate in the AV junction, the area around the AV node and the bundle of His, are referred to as ______ rhythms.

A) junctional
B) atrial
C) ventricular
D) sinus

Answer 1

junctional

Question 2

PR intervals of less than 0.12 seconds indicate:

A) an intermittent blocking of the impulse as it passes through the AV node
B) a delay in conduction of the impulse between the SA node and the ventricles
C) an increased rate of impulse discharge from the SA node
D) a pacemaker site which is either in or close to the AV junction

Answer 2

a pacemaker site which is either in or close to the AV junction

Question 3

Impulses that originate in the AV junction travel:

A) upward and cause backward or retrograde depolarization of the atria
B) horizontally, first depolarizing the skeleton of the heart then the atria and ventricles
C) mostly downward
D) across the ventricular myocardium depolarizing the ventricles in an abnormal manner

Answer 3

upward and cause backward or retrograde depolarization of the atria

Question 4

P waves resulting from impulses that originate outside the SA node are called:

A) P neutral
B) R'
C) P prime
D) Retro P

Question 5

Which of the following is a junctional dysrhythmia?

A) wandering atrial pacemaker
B) accelerated junctional rhythm
C) sick sinus syndrome
D) PAC

Question 6

Which of the following is the most distinguishing characteristic that helps identify junctional dysrhythmias?

A) Narrow QRS complexes.
B) An irregular rhythm.
C) Inverted P' waves.
D) PR intervals that are between 0.12 and 0.20 seconds in duration.

Question 7

Premature junctional complexes:

A) are preceded by an upright P' wave.
B) are typically followed by a compensatory pause.
C) have a narrow QRS complex.
D) have inverted T waves.

Question 8

When premature junctional complexes occur the first thing you see as you look across the ECG tracing is/are:

A) an irregular rhythm.
B) inverted P' waves.
C) compensatory pauses.
D) wide, bizarre shaped QRS complexes.

Question 9

When every third beat is a PJC, it is called ______ PACs.

A) unifocal
B) bigeminal
C) trigeminal
D) quadrigeminal

Question 10

In junctional escape rhythm, the pacemaker site is in the:

A) SA node
B) atrial and internodal conduction pathways
C) AV junction
D) right bundle branch

Question 11

Your patient is experiencing hypotension and lightheadedness as a result of a heart rate of 40 beats per minute. You attach the ECG monitor to see a slow, regular rhythm with an inverted P' wave immediately preceding each narrow, upright QRS complex. You note the P'R intervals are 0.10 seconds in duration. This patient is experiencing:

A) sinus bradycardia.
B) accelerated junctional rhythm.
C) wandering atrial pacemaker.
D) junctional escape rhythm.

Question 12

Causes of junctional escape rhythm include:

A) increased vagal tone over the SA node.
B) increased automaticity of the AV node
C) ventricular irritability
D) digitalis toxicity

Question 13

Treatment of symptomatic junctional escape includes:

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

Question 14

Match the following junctional rhythms with the appropriate heart rate. beats per minute dysrhythmiasjunctional tachycardia:

-junctional escape rhythm

A)less than 40
B)40 to 60
C)60 to 100
D)100 to 180

Question 15

Match the following junctional rhythms with the appropriate heart rate. beats per minute dysrhythmiasjunctional tachycardia:

-junctional tachycardia

A)less than 41
B)40 to 61
C)60 to 101
D)100 to 181

Question 16

Match the following junctional rhythms with the appropriate heart rate. beats per minute dysrhythmiasjunctional tachycardia:

-slow junctional escape

A)less than 42
B)40 to 62
C)60 to 102
D)100 to 182

Question 17

Match the following junctional rhythms with the appropriate heart rate. beats per minute dysrhythmiasjunctional tachycardia:

-accelerated junctional rhythm

A)less than 43
B)40 to 63
C)60 to 103
D)100 to 183

Question 18

Accelerated junction rhythm has:

A) a regular rhythm.
B) T waves that take the opposite direction to the QRS complexes.
C) wide QRS complexes.
D) P'R intervals of greater than 0.20 seconds.

Question 19

Causes of accelerated junctional rhythm include:

A) increased vagal tone over the SA node.
B) increased automaticity of the AV node
C) ventricular irritability
D) impulses traveling along an accessory pathway

Question 20

Junctional tachycardia has:

A) an irregular rhythm.
B) a rate of between 60 and 180 beats per minute.
C) inverted QRS complexes.
D) P'R intervals of less than 0.12 seconds.

Question 21

In AVNRT:

A) accessory conduction pathways exist between the atria and ventricles that bypass the AV node and bundle of His and allow the atria to depolarize the ventricles earlier than usual.
B) increased automaticity causes the AV node to discharge at an abnormally fast rate.
C) fast and slow pathways located within the right atrium in close proximity to or within the AV node allow for development of SVT.
D) the ventricles discharge at an abnormally fast rate and depolarize the AV node in a retrograde fashion.

Question 22

Criteria for WPW include:

A) a PR interval less than 0.12 seconds.
B) wide QRS complexes due to the presence of a delta wave.
C) elevated ST segments and inverted T waves.
D) a and b

Question 23

Initial treatment of unstable junctional tachycardia includes:

A) administering atropine.
B) administering beta blockers.
C) treating the underlying cause.
D) delivering synchronized cardioversion

Question 24

Impulses that originate in the AV junction produce inverted P' waves (when they would otherwise be upright) with a P'R interval that is less than 0.12 seconds in duration.

Question 25

P' waves that originate from the AV junction are most often buried in or follow the QRS complex.

Question 26

PJCs are thought to result from enhanced automaticity or a reentry mechanism.

Question 27

Junctional escape rhythm with a rate of less than 50 beats per minute is usually well tolerated.

Question 28

The sustained rapid ventricular rates and retrograde depolarization of the atria in junctional tachycardia can lead to compromised cardiac output in patients with underlying heart disease.

Question 29

Preexcitation syndromes occur when accessory conduction pathways exist between the atria and ventricles that bypass the AV node and bundle of His and allow the atria to depolarize the ventricles earlier than usual.

Question 30

Patients with WPW are vulnerable to PSVT.