ECG WORKOUT
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
Ch. 1 — Anatomy & Physiology of the Heart — Description &
Location / Function / Surfaces / Wall Structure / Chambers /
Valves / Blood Flow / Circulatory System / Coronary
Circulation / Cardiac Innervation
Q1 — Reference
Ch. 1 — Description and Location of the Heart
Question Stem (2–3 sentences)
A 62-year-old patient’s chest x-ray shows the cardiac silhouette
,shifted rightward after surgical removal of a left lung mass. On
continuous telemetry, expected frontal QRS axis and lead
appearance may change. Which physiologic explanation best
accounts for a rightward QRS axis shift after left lung volume
loss?
A. Right ventricular hypertrophy from increased pulmonary
pressures.
B. Clockwise rotation of the heart within the thorax due to
mediastinal shift.
C. Ischemic injury to left ventricular myocardium producing loss
of leftward forces.
D. Increased vagal tone causing slowed conduction and axis
change.
Correct Answer
B
Rationales
Correct (B): Loss of left lung volume commonly causes
mediastinal shift and rotation of the heart toward the right; this
mechanical rotation alters the vector orientation of ventricular
depolarization producing a rightward frontal QRS axis. Clinically,
lead appearances (limb leads/precordial R-wave progression)
change because the heart’s position relative to electrodes has
rotated.
Incorrect (A): RV hypertrophy would produce right-axis
deviation but requires chronic pulmonary pressure overload—
not an immediate mechanical mediastinal shift.
,Incorrect (C): Ischemic loss of left ventricular forces can shift
axis, but sudden mechanical displacement is a more likely
explanation after lung removal.
Incorrect (D): Vagal tone affects rate and AV conduction, not the
spatial axis of ventricular depolarization.
Teaching Point
Cardiac rotation or displacement shifts electrical axis by
changing the heart’s orientation to surface leads.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
Q2 — Reference
Ch. 1 — Function of the Heart / Heart Chambers
Question Stem (2–3 sentences)
A telemetry nurse notes intermittent tall, peaked P waves on
monitoring in a patient with long-standing mitral valve disease.
Considering chamber anatomy and valve pathology, which
structural change most likely explains the altered P-wave
morphology?
A. Left ventricular enlargement causing anterior displacement
of the P-wave vector.
B. Right atrial enlargement producing increased P-wave
amplitude in inferior leads.
C. Left atrial enlargement producing broad, notched P waves in
, limb leads.
D. Biatrial atrophy reducing P-wave amplitude globally.
Correct Answer
C
Rationales
Correct (C): Mitral valve disease commonly causes left atrial
enlargement; anatomically this enlarges left atrial
depolarization contribution, often producing broad, notched (or
prolonged) P waves in limb leads due to delayed left atrial
activation.
Incorrect (A): LV enlargement affects QRS morphology rather
than P waves.
Incorrect (B): Right atrial enlargement leads to tall, peaked P
waves (especially in II, III, aVF), but mitral disease more
classically enlarges the left atrium.
Incorrect (D): Atrophy would reduce amplitude, not cause
pronounced P-wave changes seen with valve disease.
Teaching Point
Mitral valve pathology → left atrial enlargement → broad,
notched P waves (atrial depolarization prolonged).
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
Ch. 1 — Anatomy & Physiology of the Heart — Description &
Location / Function / Surfaces / Wall Structure / Chambers /
Valves / Blood Flow / Circulatory System / Coronary
Circulation / Cardiac Innervation
Q1 — Reference
Ch. 1 — Description and Location of the Heart
Question Stem (2–3 sentences)
A 62-year-old patient’s chest x-ray shows the cardiac silhouette
,shifted rightward after surgical removal of a left lung mass. On
continuous telemetry, expected frontal QRS axis and lead
appearance may change. Which physiologic explanation best
accounts for a rightward QRS axis shift after left lung volume
loss?
A. Right ventricular hypertrophy from increased pulmonary
pressures.
B. Clockwise rotation of the heart within the thorax due to
mediastinal shift.
C. Ischemic injury to left ventricular myocardium producing loss
of leftward forces.
D. Increased vagal tone causing slowed conduction and axis
change.
Correct Answer
B
Rationales
Correct (B): Loss of left lung volume commonly causes
mediastinal shift and rotation of the heart toward the right; this
mechanical rotation alters the vector orientation of ventricular
depolarization producing a rightward frontal QRS axis. Clinically,
lead appearances (limb leads/precordial R-wave progression)
change because the heart’s position relative to electrodes has
rotated.
Incorrect (A): RV hypertrophy would produce right-axis
deviation but requires chronic pulmonary pressure overload—
not an immediate mechanical mediastinal shift.
,Incorrect (C): Ischemic loss of left ventricular forces can shift
axis, but sudden mechanical displacement is a more likely
explanation after lung removal.
Incorrect (D): Vagal tone affects rate and AV conduction, not the
spatial axis of ventricular depolarization.
Teaching Point
Cardiac rotation or displacement shifts electrical axis by
changing the heart’s orientation to surface leads.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
Q2 — Reference
Ch. 1 — Function of the Heart / Heart Chambers
Question Stem (2–3 sentences)
A telemetry nurse notes intermittent tall, peaked P waves on
monitoring in a patient with long-standing mitral valve disease.
Considering chamber anatomy and valve pathology, which
structural change most likely explains the altered P-wave
morphology?
A. Left ventricular enlargement causing anterior displacement
of the P-wave vector.
B. Right atrial enlargement producing increased P-wave
amplitude in inferior leads.
C. Left atrial enlargement producing broad, notched P waves in
, limb leads.
D. Biatrial atrophy reducing P-wave amplitude globally.
Correct Answer
C
Rationales
Correct (C): Mitral valve disease commonly causes left atrial
enlargement; anatomically this enlarges left atrial
depolarization contribution, often producing broad, notched (or
prolonged) P waves in limb leads due to delayed left atrial
activation.
Incorrect (A): LV enlargement affects QRS morphology rather
than P waves.
Incorrect (B): Right atrial enlargement leads to tall, peaked P
waves (especially in II, III, aVF), but mitral disease more
classically enlarges the left atrium.
Incorrect (D): Atrophy would reduce amplitude, not cause
pronounced P-wave changes seen with valve disease.
Teaching Point
Mitral valve pathology → left atrial enlargement → broad,
notched P waves (atrial depolarization prolonged).
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
