ECG WORKOUT
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1 — Reference
Ch. 1 — Description & Location of the Heart
Question Stem
A telemetry lead II rhythm strip from a patient shows normal
sinus rhythm with upright P waves in lead II and a consistent PR
interval of 0.16 sec. The nurse notes the point of maximal
impulse is displaced laterally at the left midclavicular line.
,Which anatomical statement best explains the ECG
appearance?
Options
A. The heart’s leftward orientation brings the atrial
depolarization vector closer to lead II, producing upright P
waves.
B. A lateral PMI shifts the AV node toward lead II, producing
shorter PR intervals.
C. Leftward displacement causes QRS complexes to invert in
lead II.
D. A lateral PMI indicates right atrial enlargement and negative
P waves in lead II.
Correct Answer
A
Rationales
Correct Option: The heart’s normal left-anterior orientation
aligns atrial depolarization toward lead II, producing upright P
waves; lateral PMI is consistent with leftward cardiac position.
Incorrect Options:
B — AV nodal position does not shift PR interval simply from
lateral displacement; PR reflects AV conduction time, not gross
cardiac position.
C — Leftward orientation typically does not invert QRS in lead II;
inversion would need an opposing depolarization vector.
D — Right atrial enlargement causes peaked P waves, not a
,lateral PMI; negative P waves in II would indicate ectopic atrial
focus, not PMI lateralization.
Teaching Point
Cardiac position influences surface lead vectors; leftward
orientation often yields upright P waves in lead II.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
2 — Reference
Ch. 1 — Function of the Heart
Question Stem
A post-op patient on telemetry becomes hypotensive. The
monitor shows sinus bradycardia at 40 bpm with preserved P–
QRS relationship. The nurse knows cardiac output = heart rate ×
stroke volume. Which immediate ECG-based interpretation
supports that decreased cardiac output is due to rate change
rather than stroke volume?
Options
A. Sinus bradycardia with normal QRS and unchanged waveform
morphology indicates decreased heart rate is the main driver of
reduced output.
B. Sinus bradycardia with normal waveform morphology
indicates reduced stroke volume is primary.
C. The presence of normal P waves rules out any change in
, cardiac output.
D. Bradycardia with unchanged QRS amplitude proves
preserved stroke volume.
Correct Answer
A
Rationales
Correct Option: A low sinus rate with preserved conduction and
unchanged QRS/P wave morphology suggests stroke volume is
likely unchanged acutely, so reduced heart rate is the
immediate cause of decreased cardiac output.
Incorrect Options:
B — The ECG cannot directly prove reduced stroke volume;
bradycardia primarily reduces CO via rate.
C — Normal P waves do not rule out CO changes; they only
indicate sinus origin.
D — QRS amplitude on surface ECG is not a reliable immediate
measure of stroke volume.
Teaching Point
Acute falls in cardiac output on telemetry are often rate-
mediated when ECG waveform morphology is preserved.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
3 — Reference
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1 — Reference
Ch. 1 — Description & Location of the Heart
Question Stem
A telemetry lead II rhythm strip from a patient shows normal
sinus rhythm with upright P waves in lead II and a consistent PR
interval of 0.16 sec. The nurse notes the point of maximal
impulse is displaced laterally at the left midclavicular line.
,Which anatomical statement best explains the ECG
appearance?
Options
A. The heart’s leftward orientation brings the atrial
depolarization vector closer to lead II, producing upright P
waves.
B. A lateral PMI shifts the AV node toward lead II, producing
shorter PR intervals.
C. Leftward displacement causes QRS complexes to invert in
lead II.
D. A lateral PMI indicates right atrial enlargement and negative
P waves in lead II.
Correct Answer
A
Rationales
Correct Option: The heart’s normal left-anterior orientation
aligns atrial depolarization toward lead II, producing upright P
waves; lateral PMI is consistent with leftward cardiac position.
Incorrect Options:
B — AV nodal position does not shift PR interval simply from
lateral displacement; PR reflects AV conduction time, not gross
cardiac position.
C — Leftward orientation typically does not invert QRS in lead II;
inversion would need an opposing depolarization vector.
D — Right atrial enlargement causes peaked P waves, not a
,lateral PMI; negative P waves in II would indicate ectopic atrial
focus, not PMI lateralization.
Teaching Point
Cardiac position influences surface lead vectors; leftward
orientation often yields upright P waves in lead II.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
2 — Reference
Ch. 1 — Function of the Heart
Question Stem
A post-op patient on telemetry becomes hypotensive. The
monitor shows sinus bradycardia at 40 bpm with preserved P–
QRS relationship. The nurse knows cardiac output = heart rate ×
stroke volume. Which immediate ECG-based interpretation
supports that decreased cardiac output is due to rate change
rather than stroke volume?
Options
A. Sinus bradycardia with normal QRS and unchanged waveform
morphology indicates decreased heart rate is the main driver of
reduced output.
B. Sinus bradycardia with normal waveform morphology
indicates reduced stroke volume is primary.
C. The presence of normal P waves rules out any change in
, cardiac output.
D. Bradycardia with unchanged QRS amplitude proves
preserved stroke volume.
Correct Answer
A
Rationales
Correct Option: A low sinus rate with preserved conduction and
unchanged QRS/P wave morphology suggests stroke volume is
likely unchanged acutely, so reduced heart rate is the
immediate cause of decreased cardiac output.
Incorrect Options:
B — The ECG cannot directly prove reduced stroke volume;
bradycardia primarily reduces CO via rate.
C — Normal P waves do not rule out CO changes; they only
indicate sinus origin.
D — QRS amplitude on surface ECG is not a reliable immediate
measure of stroke volume.
Teaching Point
Acute falls in cardiac output on telemetry are often rate-
mediated when ECG waveform morphology is preserved.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
3 — Reference
