PALS-Rationales.
PALS Written 2006 Precourse Self-Assessment
ECG Rhythm Identification Answer Sheet
Pediatric Rhythms (core PALS rhythms A to H; non-core rhythms I to M):
A. Normal sinus rhythm
B. Sinus tachycardia
C. Sinus bradycardia
D. Supraventricular tachycardia (SVT)
E. Wide-complex tachycardia; presumed ventricular tachycardia (monomorphic)
F. Ventricular fibrillation (VF)
G. Asystole
H. Pulseless electrical activity (PEA)
I. SVT converting to sinus rhythm with adenosine administration
J. Wide-complex tachycardia (in a child with known aberrant intraventricular
conduction; this is SVT with aberrant conduction)
K. First-degree AV block
L. Torsades de pointes (polymorphic ventricular tachycardia)
M. VF converted to organized rhythm after successful shock delivery
(defibrillation) Rhythms 1 to 8: Core PALS Rhythms (select single best answer
from rhythms A to H)
Rhythm 1 (clinical clue: heart rate 214/min)
Correct answer is E: Wide-complex tachycardia; presumed ventricular
tachycardia (monomorphic)
Pediatric ECG tip: Ventricular tachycardia is a sustained series of wide QRS
PALS Written 2006 Precourse Self- 1
Assessment
© 2006 American Heart Association
,PALS-Rationales.
complexes (ie, ventricular depolarizations) typically at a rate of at least
120/min. This VT can be further classified as monomorphic because all
complexes have the same appearance. If
PALS Written 2006 Precourse Self- 2
Assessment
© 2006 American Heart Association
,PALS-Rationales.
this rhythm is observed in a child with no history of aberrant intraventricular
conduction and no aberrant conduction apparent on 12-lead ECG, the
rhythm should be presumed to be ventricular tachycardia.
For further information: see the PALS Provider Manual Chapter 6: Recognition
and Management of Bradyarrhythmias and Tachyarrhythmias and Chapter 7:
Recognition and Management of Cardiac Arrest.
Rhythm 2 (clinical clues: heart rate 44/min; no detectable pulses)
Correct answer is H: Pulseless electrical activity (PEA)
Pediatric ECG tip: In the absence of detectable pulses, this organized rhythm
is one of the cardiac arrest rhythms—Pulseless electrical activity (PEA) (PEA).
It is treated using the asystole/PEA portion of the PALS Pulseless Arrest
algorithm. This particular rhythm may be described as an idioventricular escape
rhythm (an escape rhythm originating from a slow ventricular pacemaker
during periods of significant sinus bradycardia or high-grade AV block). It is
characterized by wide QRS complexes, and it is often seen in the setting of a
severely hypoxic-ischemic myocardium.
For further information: see the PALS Provider Manual Chapter 6: Recognition
and Management of Bradyarrhythmias and Tachyarrhythmias.
PALS Written 2006 Precourse Self- 3
Assessment
© 2006 American Heart Association
, PALS-Rationales.
Rhythm 3 (clinical clues: age 8 years; heart rate 50/min)
Correct answer is C: Sinus bradycardia.
Pediatric ECG tip: Sinus bradycardia is characterized by a sinus rhythm with
a rate that is slower than normal for the patient’s age. P waves and QRS
complexes are usually normal in appearance; the QRS is narrow.
For further information: see the PALS Provider Manual Chapter 6: Recognition
and Management of Bradyarrhythmias and Tachyarrhythmias.
Rhythm 4 (clinical clue: no detectable pulses)
Correct answer is G: Asystole
Pediatric ECG tip: Asystole is the absence of ventricular depolarization (ie,
cardiac standstill). It may be preceded by an agonal (usually wide-
complex) bradyarrhythmia (see an example of this in Rhythm 2). When you
observe this rhythm in a child who is unresponsive, apneic, and pulseless,
you should begin compressions and ventilations (CPR) immediately. Of
course, if you are uncertain whether the rhythm is asystole, confirm the
flat-line rhythm in 2 perpendicular leads but do not delay CPR for an
unresponsive, apneic child.
PALS Written 2006 Precourse Self- 4
Assessment
© 2006 American Heart Association
PALS Written 2006 Precourse Self-Assessment
ECG Rhythm Identification Answer Sheet
Pediatric Rhythms (core PALS rhythms A to H; non-core rhythms I to M):
A. Normal sinus rhythm
B. Sinus tachycardia
C. Sinus bradycardia
D. Supraventricular tachycardia (SVT)
E. Wide-complex tachycardia; presumed ventricular tachycardia (monomorphic)
F. Ventricular fibrillation (VF)
G. Asystole
H. Pulseless electrical activity (PEA)
I. SVT converting to sinus rhythm with adenosine administration
J. Wide-complex tachycardia (in a child with known aberrant intraventricular
conduction; this is SVT with aberrant conduction)
K. First-degree AV block
L. Torsades de pointes (polymorphic ventricular tachycardia)
M. VF converted to organized rhythm after successful shock delivery
(defibrillation) Rhythms 1 to 8: Core PALS Rhythms (select single best answer
from rhythms A to H)
Rhythm 1 (clinical clue: heart rate 214/min)
Correct answer is E: Wide-complex tachycardia; presumed ventricular
tachycardia (monomorphic)
Pediatric ECG tip: Ventricular tachycardia is a sustained series of wide QRS
PALS Written 2006 Precourse Self- 1
Assessment
© 2006 American Heart Association
,PALS-Rationales.
complexes (ie, ventricular depolarizations) typically at a rate of at least
120/min. This VT can be further classified as monomorphic because all
complexes have the same appearance. If
PALS Written 2006 Precourse Self- 2
Assessment
© 2006 American Heart Association
,PALS-Rationales.
this rhythm is observed in a child with no history of aberrant intraventricular
conduction and no aberrant conduction apparent on 12-lead ECG, the
rhythm should be presumed to be ventricular tachycardia.
For further information: see the PALS Provider Manual Chapter 6: Recognition
and Management of Bradyarrhythmias and Tachyarrhythmias and Chapter 7:
Recognition and Management of Cardiac Arrest.
Rhythm 2 (clinical clues: heart rate 44/min; no detectable pulses)
Correct answer is H: Pulseless electrical activity (PEA)
Pediatric ECG tip: In the absence of detectable pulses, this organized rhythm
is one of the cardiac arrest rhythms—Pulseless electrical activity (PEA) (PEA).
It is treated using the asystole/PEA portion of the PALS Pulseless Arrest
algorithm. This particular rhythm may be described as an idioventricular escape
rhythm (an escape rhythm originating from a slow ventricular pacemaker
during periods of significant sinus bradycardia or high-grade AV block). It is
characterized by wide QRS complexes, and it is often seen in the setting of a
severely hypoxic-ischemic myocardium.
For further information: see the PALS Provider Manual Chapter 6: Recognition
and Management of Bradyarrhythmias and Tachyarrhythmias.
PALS Written 2006 Precourse Self- 3
Assessment
© 2006 American Heart Association
, PALS-Rationales.
Rhythm 3 (clinical clues: age 8 years; heart rate 50/min)
Correct answer is C: Sinus bradycardia.
Pediatric ECG tip: Sinus bradycardia is characterized by a sinus rhythm with
a rate that is slower than normal for the patient’s age. P waves and QRS
complexes are usually normal in appearance; the QRS is narrow.
For further information: see the PALS Provider Manual Chapter 6: Recognition
and Management of Bradyarrhythmias and Tachyarrhythmias.
Rhythm 4 (clinical clue: no detectable pulses)
Correct answer is G: Asystole
Pediatric ECG tip: Asystole is the absence of ventricular depolarization (ie,
cardiac standstill). It may be preceded by an agonal (usually wide-
complex) bradyarrhythmia (see an example of this in Rhythm 2). When you
observe this rhythm in a child who is unresponsive, apneic, and pulseless,
you should begin compressions and ventilations (CPR) immediately. Of
course, if you are uncertain whether the rhythm is asystole, confirm the
flat-line rhythm in 2 perpendicular leads but do not delay CPR for an
unresponsive, apneic child.
PALS Written 2006 Precourse Self- 4
Assessment
© 2006 American Heart Association
