ECG WORKOUT
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1️⃣
Reference
Ch. 1 — Description and Location of the Heart
Question Stem
A telemetry strip shows new, persistent low-voltage QRS
complexes and the nurse notes muffled heart sounds on
examination. Which anatomic relationship best explains why
pericardial fluid produces these findings? Answer requires
,integrating cardiac location, surrounding spaces, and physical
exam correlation.
Options
A. The heart lies centrally in the mediastinum so pericardial
fluid attenuates electrical signals to surface leads.
B. The apex of the heart is posterior, so fluid selectively
dampens left-sided leads.
C. The heart rests on the vertebral column; posterior fluid
causes low voltages anteriorly.
D. The right heart is positioned laterally, so pericardial fluid only
affects right chest leads.
Correct Answer
A
Rationales
Correct (A): The heart occupies the middle mediastinum; an
accumulating pericardial effusion surrounds the heart,
increasing distance and insulating the myocardium from surface
electrodes and the stethoscope—producing low QRS voltages
and muffled sounds.
Incorrect (B): The apex is anterior-inferior and leftward, not
posterior; fluid does not selectively dampen left leads only.
Incorrect (C): The heart rests anterior to the vertebral column;
posterior fluid alone would not explain global low voltages.
Incorrect (D): Pericardial fluid encases the whole heart; it does
not selectively affect only the right chest leads.
,Teaching Point
Pericardial effusion surrounds the heart in the mediastinum,
uniformly dampening electrical and acoustic transmission.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
2️⃣
Reference
Ch. 1 — Function of the Heart
Question Stem
A post-op patient on telemetry has a sustained increase in heart
rate with unchanged stroke volume. The nurse recognizes that
cardiac output is most directly influenced by which paired
physiologic variables from the heart’s function? Use cardiac
function principles to choose the best pair.
Options
A. Heart rate and systemic vascular resistance
B. Stroke volume and heart rate
C. Endocardial thickness and chamber position
D. Coronary blood flow and valve competence
Correct Answer
B
, Rationales
Correct (B): Cardiac output equals stroke volume × heart rate; a
change in either variable directly alters output.
Incorrect (A): Systemic vascular resistance affects afterload and
indirectly stroke volume, but cardiac output is not the direct
product of heart rate and resistance.
Incorrect (C): Wall thickness and chamber position influence
mechanics, but they are not the primary determinants of
instantaneous cardiac output.
Incorrect (D): Coronary flow and valve competence affect
myocardial performance and forward flow over time, but they
are not the direct multiplicative components of cardiac output.
Teaching Point
Cardiac output = heart rate × stroke volume; both are primary
determinants of perfusion.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
3️⃣
Reference
Ch. 1 — Heart Surfaces
Question Stem
A telemetry alarm accompanies new hypotension and elevated
jugular venous pressure. Bedside inspection shows a bulge on
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1️⃣
Reference
Ch. 1 — Description and Location of the Heart
Question Stem
A telemetry strip shows new, persistent low-voltage QRS
complexes and the nurse notes muffled heart sounds on
examination. Which anatomic relationship best explains why
pericardial fluid produces these findings? Answer requires
,integrating cardiac location, surrounding spaces, and physical
exam correlation.
Options
A. The heart lies centrally in the mediastinum so pericardial
fluid attenuates electrical signals to surface leads.
B. The apex of the heart is posterior, so fluid selectively
dampens left-sided leads.
C. The heart rests on the vertebral column; posterior fluid
causes low voltages anteriorly.
D. The right heart is positioned laterally, so pericardial fluid only
affects right chest leads.
Correct Answer
A
Rationales
Correct (A): The heart occupies the middle mediastinum; an
accumulating pericardial effusion surrounds the heart,
increasing distance and insulating the myocardium from surface
electrodes and the stethoscope—producing low QRS voltages
and muffled sounds.
Incorrect (B): The apex is anterior-inferior and leftward, not
posterior; fluid does not selectively dampen left leads only.
Incorrect (C): The heart rests anterior to the vertebral column;
posterior fluid alone would not explain global low voltages.
Incorrect (D): Pericardial fluid encases the whole heart; it does
not selectively affect only the right chest leads.
,Teaching Point
Pericardial effusion surrounds the heart in the mediastinum,
uniformly dampening electrical and acoustic transmission.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
2️⃣
Reference
Ch. 1 — Function of the Heart
Question Stem
A post-op patient on telemetry has a sustained increase in heart
rate with unchanged stroke volume. The nurse recognizes that
cardiac output is most directly influenced by which paired
physiologic variables from the heart’s function? Use cardiac
function principles to choose the best pair.
Options
A. Heart rate and systemic vascular resistance
B. Stroke volume and heart rate
C. Endocardial thickness and chamber position
D. Coronary blood flow and valve competence
Correct Answer
B
, Rationales
Correct (B): Cardiac output equals stroke volume × heart rate; a
change in either variable directly alters output.
Incorrect (A): Systemic vascular resistance affects afterload and
indirectly stroke volume, but cardiac output is not the direct
product of heart rate and resistance.
Incorrect (C): Wall thickness and chamber position influence
mechanics, but they are not the primary determinants of
instantaneous cardiac output.
Incorrect (D): Coronary flow and valve competence affect
myocardial performance and forward flow over time, but they
are not the direct multiplicative components of cardiac output.
Teaching Point
Cardiac output = heart rate × stroke volume; both are primary
determinants of perfusion.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. 1.
3️⃣
Reference
Ch. 1 — Heart Surfaces
Question Stem
A telemetry alarm accompanies new hypotension and elevated
jugular venous pressure. Bedside inspection shows a bulge on
