ECG WORKOUT
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1
Reference
Ch. 1 — Description & Location of the Heart
Stem
A telemetry strip shows a normal sinus rhythm at 70 bpm with
right-axis deviation on the frontal-plane leads (QRS axis ~
+110°). Which anatomic explanation best accounts for the
electrical axis shift?
,Options
A. Dextrocardia (apex oriented to the right)
B. Left ventricular hypertrophy shifting vector leftward
C. Right ventricular hypertrophy or enlargement shifting vector
rightward
D. Pericardial effusion electrically insulating the heart
Correct answer
C
Rationales
Correct (C): Right ventricular hypertrophy/enlargement
increases the electrical forces directed to the right, producing
right-axis deviation; anatomy of an enlarged RV explains the
axis shift.
A: Dextrocardia causes mirror-image ECG changes with reversal
of lead patterns, not an isolated right-axis deviation in an
otherwise normal-appearing strip.
B: LV hypertrophy typically produces left-axis deviation, not
right-axis deviation.
D: Pericardial effusion reduces voltage globally but does not
selectively shift the frontal-plane axis to the right.
Teaching point
Right-axis deviation commonly reflects increased right
ventricular electrical forces.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
,2
Reference
Ch. 1 — Function of the Heart
Stem
Telemetry shows sinus tachycardia at 120 bpm with low-
amplitude QRS complexes and no ST changes. A patient has
acute shortness of breath and muffled heart sounds. Which
anatomic/physiologic failure best explains these findings?
Options
A. Acute left ventricular systolic failure causing global low
voltage
B. Cardiac tamponade with impaired ventricular filling and low
QRS voltage
C. Right-sided heart failure from RV infarction producing low
QRS voltage
D. Acute myocardial ischemia producing hyperdynamic
myocardium and low voltage
Correct answer
B
Rationales
Correct (B): Cardiac tamponade (fluid in pericardial space)
causes muffled heart sounds, low-voltage QRS, and signs of
impaired filling; clinically fits shortness of breath and
tachycardia.
, A: LV systolic failure causes pulmonary edema and dyspnea but
usually not globally low QRS voltage with muffled sounds.
C: RV infarction may cause hypotension and JVD but typically
does not produce muffled heart sounds and diffuse low
voltages.
D: Acute ischemia produces ST/T changes more commonly than
global voltage reduction and muffled sounds.
Teaching point
Pericardial fluid electrically dampens QRS amplitude and
impairs diastolic filling.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
3
Reference
Ch. 1 — Heart Surfaces
Stem
A monitor strip shows frequent premature ventricular
complexes (PVCs) with compensatory pauses. The patient’s
exam reveals a displaced point of maximal impulse (PMI)
laterally. Which anatomical change best explains the lateral PMI
and PVC predisposition?
Options
A. Left ventricular dilation/hypertrophy increasing ectopic
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1
Reference
Ch. 1 — Description & Location of the Heart
Stem
A telemetry strip shows a normal sinus rhythm at 70 bpm with
right-axis deviation on the frontal-plane leads (QRS axis ~
+110°). Which anatomic explanation best accounts for the
electrical axis shift?
,Options
A. Dextrocardia (apex oriented to the right)
B. Left ventricular hypertrophy shifting vector leftward
C. Right ventricular hypertrophy or enlargement shifting vector
rightward
D. Pericardial effusion electrically insulating the heart
Correct answer
C
Rationales
Correct (C): Right ventricular hypertrophy/enlargement
increases the electrical forces directed to the right, producing
right-axis deviation; anatomy of an enlarged RV explains the
axis shift.
A: Dextrocardia causes mirror-image ECG changes with reversal
of lead patterns, not an isolated right-axis deviation in an
otherwise normal-appearing strip.
B: LV hypertrophy typically produces left-axis deviation, not
right-axis deviation.
D: Pericardial effusion reduces voltage globally but does not
selectively shift the frontal-plane axis to the right.
Teaching point
Right-axis deviation commonly reflects increased right
ventricular electrical forces.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
,2
Reference
Ch. 1 — Function of the Heart
Stem
Telemetry shows sinus tachycardia at 120 bpm with low-
amplitude QRS complexes and no ST changes. A patient has
acute shortness of breath and muffled heart sounds. Which
anatomic/physiologic failure best explains these findings?
Options
A. Acute left ventricular systolic failure causing global low
voltage
B. Cardiac tamponade with impaired ventricular filling and low
QRS voltage
C. Right-sided heart failure from RV infarction producing low
QRS voltage
D. Acute myocardial ischemia producing hyperdynamic
myocardium and low voltage
Correct answer
B
Rationales
Correct (B): Cardiac tamponade (fluid in pericardial space)
causes muffled heart sounds, low-voltage QRS, and signs of
impaired filling; clinically fits shortness of breath and
tachycardia.
, A: LV systolic failure causes pulmonary edema and dyspnea but
usually not globally low QRS voltage with muffled sounds.
C: RV infarction may cause hypotension and JVD but typically
does not produce muffled heart sounds and diffuse low
voltages.
D: Acute ischemia produces ST/T changes more commonly than
global voltage reduction and muffled sounds.
Teaching point
Pericardial fluid electrically dampens QRS amplitude and
impairs diastolic filling.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
3
Reference
Ch. 1 — Heart Surfaces
Stem
A monitor strip shows frequent premature ventricular
complexes (PVCs) with compensatory pauses. The patient’s
exam reveals a displaced point of maximal impulse (PMI)
laterally. Which anatomical change best explains the lateral PMI
and PVC predisposition?
Options
A. Left ventricular dilation/hypertrophy increasing ectopic
