Deck 5: Junctional Rhythms

Question 1

The atrioventricular (AV) junction consists of the _____.

A) SA and AV nodes
B) AV node and the Purkinje fibers
C) AV node and nonbranching portion of the bundle of His
D) AV node, bundle of His, and the right and left bundle branches

Answer 1

C
The AV node and the nonbranching portion of the bundle of His are called the AV junction. The bundle of His has pacemaker cells that are capable of discharging at a rhythmic rate of 40 to 60 beats/min.

Question 2

Identify the following rhythm (lead II).

A) Sinus arrhythmia
B) Sinus rhythm with junctional escape beats
C) Sinus tachycardia with premature atrial complexes
D) Sinus tachycardia with premature junctional complexes

Answer 2

D
The rhythm strip shows a sinus tachycardia with premature junctional complexes.

Question 3

A beat originating from the AV junction that appears later than the next expected sinus beat is called a(n) _______________.

Answer 3

junctional escape beat

Question 4

If seen, the P wave of a rhythm originating in the AV junction will appear _____ in lead II.

A) upright
B) inverted
C) tall and peaked
D) wide and notched

Question 5

A beat originating from the AV junction that appears later than the next expected sinus beat is called a _____.

A) junctional escape beat
B) period of SA block
C) premature junctional complex (PJC)
D) premature atrial complex (PAC)

Question 6

The pacemaker cells in the AV junction are located near the nonbranching portion of the bundle of His.

Question 7

Identify the following rhythm (lead II).

A) Accelerated junctional rhythm
B) Sinus rhythm
C) Junctional rhythm
D) Sinus arrhythmia

Question 8

Identify the following rhythm (lead II).

A) Junctional tachycardia
B) Sinus rhythm with PACs
C) Sinus rhythm with PJCs
D) Accelerated junctional rhythm

Question 9

Which of the following medications increases heart rate by accelerating the SA node discharge rate and blocking the vagus nerve?

A) Digitalis
B) Atropine
C) Amiodarone
D) Beta-blocker

Question 10

In a junctional rhythm viewed in lead II, where is the location of the P wave on the ECG if atrial depolarization precedes ventricular depolarization?

A) Before the QRS complex
B) During the QRS complex
C) After the QRS complex

Question 11

In a junctional rhythm viewed in lead II, where is the location of the P wave on the ECG if atrial and ventricular depolarization occur simultaneously?

A) Before the QRS complex
B) During the QRS complex
C) After the QRS complex

Question 12

The AV junction consists of the AV node and the nonbranching portion of the bundle of His.

Question 13

Adenosine is the drug of choice when treating a symptomatic patient with a junctional rhythm at a rate of 40 beats/min.

Question 14

Common causes of junctional dysrhythmias may include acute coronary syndromes and _____.

A) hyperthyroidism
B) hypovolemia
C) digitalis toxicity
D) hypoxia

Question 15

A junctional escape rhythm occurs because of _____.

A) severe chronic obstructive pulmonary disease
B) multiple irritable sites firing within the AV junction
C) slowing of the rate of the heart's primary pacemaker
D) intrathoracic pressure changes associated with the normal respiratory cycle

Question 16

An escape rhythm is initiated by a lower pacemaker site when the sinoatrial (SA) node slows or fails to initiate an impulse.

Question 17

Depending on the severity of the patient's signs and symptoms, management of slow rhythms originating from the AV junction may require intervention including _____.

A) defibrillation
B) intravenous atropine
C) synchronized cardioversion
D) vagal maneuvers or adenosine, or both

Question 18

If the AV junction paces the heart, the electrical impulse must travel in a backward direction to activate the atria. This is called _____ conduction.

Question 19

A(n) _____ pause often follows a PJC and represents the delay during which the SA node resets its rhythm for the next beat.

Question 20

The usual rate of nonparoxysmal junctional tachycardia is _____ beats/min.

A) 50 to 80
B) 80 to 120
C) 101 to 140
D) 150 to 300

Question 21

Identify the following rhythm (lead II): ____________________

Question 22

Identify the following rhythm (lead II): ____________________

Question 23

Identify the following rhythm: ____________________

Question 24

Identify the following rhythm (lead II): ____________________

Question 25

Identify the following rhythm (lead II): ____________________

Question 26

Identify the following rhythm (lead II): ____________________

Question 27

Identify the following rhythm: ____________________

Question 28

Identify the following rhythm (lead II): ____________________

Question 29

Identify the following rhythm: ____________________

Question 30

Identify the following rhythm (lead II): ____________________

Question 31

Identify the following rhythm (lead II): ____________________

Question 32

Identify the following rhythm (lead II): ____________________

Question 33

Identify the following rhythm (lead II): ____________________

Question 34

Identify the following rhythm (lead II): ____________________

Question 35

Identify the following rhythm (lead II): ____________________

Question 36

Identify the following rhythm: ____________________

Question 37

Identify the following rhythm (lead II): ____________________

Question 38

Identify the following rhythm: ____________________

Question 39

Identify the following rhythm (lead II): ____________________

Question 40

Identify the following rhythm (lead II): ____________________

Question 41

Complete the following ECG criteria for an accelerated junctional rhythm:

Question 42

Identify the following rhythm (lead II): ____________________

Question 43

Identify the following rhythm (lead II): ____________________

Question 44

Identify the following rhythm (lead II): ____________________

Question 45

Complete the following ECG criteria for a junctional escape rhythm:

Question 46

Identify the following rhythm (lead II): ____________________

Question 47

Complete the following ECG criteria for a junctional tachycardia:

Question 48

List four reasons why the AV junction may assume responsibility for pacing the heart.

Question 49

Indicate the ventricular rates for each of the following junctional dysrhythmias:

Question 50

Identify the following rhythm (lead II): ____________________

Question 51

Identify the following rhythm (lead II): ____________________