Chapter 06: Ventricular Rhythms
Aehlert: ECGs Made Easy, 6th Edition
MULTIPLE CHOICE
1. Which of the following best describes an idioventricular rhythm?
a. Rapid, chaotic rhythm with no pattern or regularity
b. Gradual alteration in the amplitude and direction of the QRS; atrial rate
indiscernible; ventricular rate 150 to 250 beats/min
c. Essentially regular ventricular rhythm with QRS complexes measuring 0.12 second
or greater; atrial rate not discernible; ventricular rate 20 to 40 beats/min
d. Regular ventricular rhythm with QRS complexes measuring less than 0.10 second;
P waves may occur before, during, or after the QRS; ventricular rate 40 to 60
beats/min
ANS: C
An idioventricular rhythm (IVR), which is also called a ventricular escape rhythm, exists
when three or more ventricular escape beats occur in a row at a rate of 20 to 40 beats/min (i.e.,
the intrinsic firing rate of the Purkinje fibers). The QRS complexes seen in IVR are wide and
bizarre because the impulses begin in the ventricles, bypassing the normal conduction
pathway. When the ventricular rate slows to a rate of less than 20 beats/min, some
practitioners refer to the rhythm as an agonal rhythm or dying heart.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
2. What is meant by the term pulseless electrical activity (PEA)?
a. A chaotic rhythm that is likely to degenerate into cardiac arrest
b. An organized rhythm on the cardiac monitor (other than VT), although a pulse is
not present
c. A slow rhythm with a wide QRS complex
d. A flat line on the cardiac monitor
ANS: B
If the patient is not breathing and has no pulse despite the appearance of organized electrical
activity on the cardiac monitor (other than VT), pulseless electrical activity (PEA) exists.
OBJ: Explain the term pulseless electrical activity.
3. How would you differentiate a junctional escape rhythm at 40 beats/min from a ventricular
escape rhythm at the same rate?
a. It is impossible to differentiate a junctional escape rhythm from a ventricular
escape rhythm.
b. The junctional escape rhythm will have a narrow-QRS complex; the ventricular
escape rhythm will have a wide QRS complex.
c. The rate (40 beats/min) would indicate a junctional escape rhythm, not a ventricular
escape rhythm.
d. The junctional escape rhythm will have a wide QRS complex; the ventricular
escape rhythm will have a narrow-QRS complex.
, ANS: B
Although junctional and ventricular rhythms are ectopic pacemaker sites, their rhythms can
generally be differentiated by the width of their QRS complexes. The junctional escape
rhythm will have a narrow-QRS complex; the ventricular escape rhythm will have a wide
QRS complex.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
4. Which of the following best describes an accelerated idioventricular rhythm (AIVR)?
a. Rapid, chaotic rhythm with no pattern or regularity
b. Gradual alteration in the amplitude and direction of the QRS; atrial rate
indiscernible, ventricular rate 150 to 250 beats/min
c. Regular ventricular rhythm with QRS complexes measuring 0.10 second or less; P
waves may occur before, during, or after the QRS; ventricular rate 41 to 60
beats/min
d. Essentially regular ventricular rhythm with QRS complexes measuring 0.12 second
or greater; atrial rate not discernible; ventricular rate 41 to 100 beats/min
ANS: D
Characteristics of accelerated idioventricular rhythm:
Rhythm Ventricular rhythm is essentially
regular.
Rate 41 to 100 (41 to 120 per some
cardiologists) beats/min.
P waves Usually absent or, with retrograde
conduction to the atria, may appear after
the QRS (usually upright in the ST
segment or T wave).
PR interval None.
QRS duration Greater than 0.12 second; the T wave
frequently in the opposite direction of
the QRS complex.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an accelerated idioventricular rhythm.
5. The rate of an idioventricular rhythm is _____ beats/min.
a. 20 to 40
b. 41 to 60
c. 61 to 100
d. 101 to 180
ANS: A
The intrinsic rate of an idioventricular rhythm, which is also called a ventricular escape
rhythm, is 20 to 40 beats/min (i.e., the intrinsic firing rate of the Purkinje fibers).
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
, TRUE/FALSE
1. The term premature ventricular complex is technically more correct than premature
ventricular contraction.
ANS: T
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for premature ventricular complexes (PVCs).
2. Transcutaneous pacing is the treatment of choice for pulseless ventricular tachycardia or
ventricular fibrillation.
ANS: F
Cardiopulmonary resuscitation and defibrillation are the treatments of choice for pulseless
ventricular tachycardia or ventricular fibrillation.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for ventricular fibrillation.
3. Medications to suppress an idioventricular rhythm should generally be avoided.
ANS: T
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
4. An idioventricular (ventricular escape) rhythm has an intrinsic rate of 40 to 60 beats/min.
ANS: F
An idioventricular rhythm (IVR), which is also called a ventricular escape rhythm, exists
when three or more ventricular escape beats occur in a row at a rate of 20 to 40 beats/min (i.e.,
the intrinsic firing rate of the Purkinje fibers).
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
5. Sustained monomorphic VT is often associated with underlying heart disease, particularly
myocardial ischemia, and rarely occurs in patients without underlying structural heart disease.
ANS: T
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for monomorphic VT.
SHORT ANSWER
1. Complete the following ECG criteria for ventricular fibrillation:
Rhythm
Rate
P waves
PR interval
QRS duration
Aehlert: ECGs Made Easy, 6th Edition
MULTIPLE CHOICE
1. Which of the following best describes an idioventricular rhythm?
a. Rapid, chaotic rhythm with no pattern or regularity
b. Gradual alteration in the amplitude and direction of the QRS; atrial rate
indiscernible; ventricular rate 150 to 250 beats/min
c. Essentially regular ventricular rhythm with QRS complexes measuring 0.12 second
or greater; atrial rate not discernible; ventricular rate 20 to 40 beats/min
d. Regular ventricular rhythm with QRS complexes measuring less than 0.10 second;
P waves may occur before, during, or after the QRS; ventricular rate 40 to 60
beats/min
ANS: C
An idioventricular rhythm (IVR), which is also called a ventricular escape rhythm, exists
when three or more ventricular escape beats occur in a row at a rate of 20 to 40 beats/min (i.e.,
the intrinsic firing rate of the Purkinje fibers). The QRS complexes seen in IVR are wide and
bizarre because the impulses begin in the ventricles, bypassing the normal conduction
pathway. When the ventricular rate slows to a rate of less than 20 beats/min, some
practitioners refer to the rhythm as an agonal rhythm or dying heart.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
2. What is meant by the term pulseless electrical activity (PEA)?
a. A chaotic rhythm that is likely to degenerate into cardiac arrest
b. An organized rhythm on the cardiac monitor (other than VT), although a pulse is
not present
c. A slow rhythm with a wide QRS complex
d. A flat line on the cardiac monitor
ANS: B
If the patient is not breathing and has no pulse despite the appearance of organized electrical
activity on the cardiac monitor (other than VT), pulseless electrical activity (PEA) exists.
OBJ: Explain the term pulseless electrical activity.
3. How would you differentiate a junctional escape rhythm at 40 beats/min from a ventricular
escape rhythm at the same rate?
a. It is impossible to differentiate a junctional escape rhythm from a ventricular
escape rhythm.
b. The junctional escape rhythm will have a narrow-QRS complex; the ventricular
escape rhythm will have a wide QRS complex.
c. The rate (40 beats/min) would indicate a junctional escape rhythm, not a ventricular
escape rhythm.
d. The junctional escape rhythm will have a wide QRS complex; the ventricular
escape rhythm will have a narrow-QRS complex.
, ANS: B
Although junctional and ventricular rhythms are ectopic pacemaker sites, their rhythms can
generally be differentiated by the width of their QRS complexes. The junctional escape
rhythm will have a narrow-QRS complex; the ventricular escape rhythm will have a wide
QRS complex.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
4. Which of the following best describes an accelerated idioventricular rhythm (AIVR)?
a. Rapid, chaotic rhythm with no pattern or regularity
b. Gradual alteration in the amplitude and direction of the QRS; atrial rate
indiscernible, ventricular rate 150 to 250 beats/min
c. Regular ventricular rhythm with QRS complexes measuring 0.10 second or less; P
waves may occur before, during, or after the QRS; ventricular rate 41 to 60
beats/min
d. Essentially regular ventricular rhythm with QRS complexes measuring 0.12 second
or greater; atrial rate not discernible; ventricular rate 41 to 100 beats/min
ANS: D
Characteristics of accelerated idioventricular rhythm:
Rhythm Ventricular rhythm is essentially
regular.
Rate 41 to 100 (41 to 120 per some
cardiologists) beats/min.
P waves Usually absent or, with retrograde
conduction to the atria, may appear after
the QRS (usually upright in the ST
segment or T wave).
PR interval None.
QRS duration Greater than 0.12 second; the T wave
frequently in the opposite direction of
the QRS complex.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an accelerated idioventricular rhythm.
5. The rate of an idioventricular rhythm is _____ beats/min.
a. 20 to 40
b. 41 to 60
c. 61 to 100
d. 101 to 180
ANS: A
The intrinsic rate of an idioventricular rhythm, which is also called a ventricular escape
rhythm, is 20 to 40 beats/min (i.e., the intrinsic firing rate of the Purkinje fibers).
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
, TRUE/FALSE
1. The term premature ventricular complex is technically more correct than premature
ventricular contraction.
ANS: T
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for premature ventricular complexes (PVCs).
2. Transcutaneous pacing is the treatment of choice for pulseless ventricular tachycardia or
ventricular fibrillation.
ANS: F
Cardiopulmonary resuscitation and defibrillation are the treatments of choice for pulseless
ventricular tachycardia or ventricular fibrillation.
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for ventricular fibrillation.
3. Medications to suppress an idioventricular rhythm should generally be avoided.
ANS: T
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
4. An idioventricular (ventricular escape) rhythm has an intrinsic rate of 40 to 60 beats/min.
ANS: F
An idioventricular rhythm (IVR), which is also called a ventricular escape rhythm, exists
when three or more ventricular escape beats occur in a row at a rate of 20 to 40 beats/min (i.e.,
the intrinsic firing rate of the Purkinje fibers).
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for an idioventricular rhythm.
5. Sustained monomorphic VT is often associated with underlying heart disease, particularly
myocardial ischemia, and rarely occurs in patients without underlying structural heart disease.
ANS: T
OBJ: Describe the ECG characteristics, possible causes, signs and symptoms, and initial emergency
care for monomorphic VT.
SHORT ANSWER
1. Complete the following ECG criteria for ventricular fibrillation:
Rhythm
Rate
P waves
PR interval
QRS duration
