ECG WORKOUT
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1
Reference
Ch. 1 — Description and Location of the Heart
Question Stem
A telemetry strip shows a regular rhythm at 60–70 bpm with
upright P waves in lead II preceding every QRS and normal PR
interval. The patient reports no symptoms. Which anatomical
feature best explains the origin of this rhythm?
,Options
A. Ectopic focus in the atrioventricular (AV) junction.
B. Sinoatrial (SA) node located in the right atrium near the
superior vena cava.
C. Left ventricular Purkinje network pacing the heart.
D. Reentrant circuit around the tricuspid valve annulus.
Correct Answer
B
Rationales
Correct (B): The described rhythm is normal sinus rhythm;
impulses originate from the SA node situated in the right atrium
near the superior vena cava, producing upright P waves in lead
II. This anatomical location explains physiologic pacemaking.
Incorrect (A): An AV junctional focus would produce absent or
inverted P waves or P waves after the QRS, not normal upright P
waves before each QRS.
Incorrect (C): Purkinje or ventricular-origin rhythms cause wide
QRS complexes and usually dissociated/absent P waves.
Incorrect (D): A reentrant circuit around a valve annulus
typically produces atrial tachyarrhythmias, not normal sinus
rhythm.
Teaching Point
Normal sinus rhythm arises from the SA node in the right
atrium near the SVC.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
,Interpretation (8th ed.). Ch. Description and Location of the
Heart.
2
Reference
Ch. 1 — Function of the Heart
Question Stem
A patient’s telemetry shows sinus tachycardia at 120 bpm
during pain and anxiety. Which physiologic mechanism most
directly explains the tachycardia in terms of cardiac function?
Options
A. Increased parasympathetic output causing enhanced AV
nodal conduction.
B. Increased venous return causing immediate decrease in heart
rate.
C. Sympathetic stimulation increasing SA node firing rate and
contractility.
D. Coronary artery vasoconstriction decreasing myocardial
oxygen demand.
Correct Answer
C
Rationales
Correct (C): Sympathetic stimulation raises the SA node firing
rate and increases cardiac contractility, producing sinus
tachycardia during pain or anxiety—directly tied to the heart’s
, autonomic control of function.
Incorrect (A): Parasympathetic output slows the heart and
reduces AV nodal conduction—opposite of tachycardia.
Incorrect (B): Increased venous return (via Bainbridge reflex)
can increase heart rate, but acute tachycardia during
pain/anxiety is primarily sympathetic-mediated.
Incorrect (D): Coronary vasoconstriction would reduce oxygen
supply and not directly cause sinus tachycardia as a first
mechanism.
Teaching Point
Sympathetic activation increases SA node firing and
contractility, causing sinus tachycardia.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. Function of the Heart.
3
Reference
Ch. 1 — Heart Surfaces
Question Stem
A telemetry rhythm shows frequent premature ventricular
complexes (PVCs) with wide QRS complexes and no preceding P
waves. A coronary angiogram localizes ischemia to the inferior
surface of the heart. Which coronary distribution/anatomical
relation best explains PVCs originating from this surface?
EXERCISES IN ARRHYTHMIA
INTERPRETATION
8TH EDITION
• AUTHOR(S)JANE HUFF
TEST BANK
1
Reference
Ch. 1 — Description and Location of the Heart
Question Stem
A telemetry strip shows a regular rhythm at 60–70 bpm with
upright P waves in lead II preceding every QRS and normal PR
interval. The patient reports no symptoms. Which anatomical
feature best explains the origin of this rhythm?
,Options
A. Ectopic focus in the atrioventricular (AV) junction.
B. Sinoatrial (SA) node located in the right atrium near the
superior vena cava.
C. Left ventricular Purkinje network pacing the heart.
D. Reentrant circuit around the tricuspid valve annulus.
Correct Answer
B
Rationales
Correct (B): The described rhythm is normal sinus rhythm;
impulses originate from the SA node situated in the right atrium
near the superior vena cava, producing upright P waves in lead
II. This anatomical location explains physiologic pacemaking.
Incorrect (A): An AV junctional focus would produce absent or
inverted P waves or P waves after the QRS, not normal upright P
waves before each QRS.
Incorrect (C): Purkinje or ventricular-origin rhythms cause wide
QRS complexes and usually dissociated/absent P waves.
Incorrect (D): A reentrant circuit around a valve annulus
typically produces atrial tachyarrhythmias, not normal sinus
rhythm.
Teaching Point
Normal sinus rhythm arises from the SA node in the right
atrium near the SVC.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
,Interpretation (8th ed.). Ch. Description and Location of the
Heart.
2
Reference
Ch. 1 — Function of the Heart
Question Stem
A patient’s telemetry shows sinus tachycardia at 120 bpm
during pain and anxiety. Which physiologic mechanism most
directly explains the tachycardia in terms of cardiac function?
Options
A. Increased parasympathetic output causing enhanced AV
nodal conduction.
B. Increased venous return causing immediate decrease in heart
rate.
C. Sympathetic stimulation increasing SA node firing rate and
contractility.
D. Coronary artery vasoconstriction decreasing myocardial
oxygen demand.
Correct Answer
C
Rationales
Correct (C): Sympathetic stimulation raises the SA node firing
rate and increases cardiac contractility, producing sinus
tachycardia during pain or anxiety—directly tied to the heart’s
, autonomic control of function.
Incorrect (A): Parasympathetic output slows the heart and
reduces AV nodal conduction—opposite of tachycardia.
Incorrect (B): Increased venous return (via Bainbridge reflex)
can increase heart rate, but acute tachycardia during
pain/anxiety is primarily sympathetic-mediated.
Incorrect (D): Coronary vasoconstriction would reduce oxygen
supply and not directly cause sinus tachycardia as a first
mechanism.
Teaching Point
Sympathetic activation increases SA node firing and
contractility, causing sinus tachycardia.
Citation
Huff, J. (2022). ECG Workout: Exercises in Arrhythmia
Interpretation (8th ed.). Ch. Function of the Heart.
3
Reference
Ch. 1 — Heart Surfaces
Question Stem
A telemetry rhythm shows frequent premature ventricular
complexes (PVCs) with wide QRS complexes and no preceding P
waves. A coronary angiogram localizes ischemia to the inferior
surface of the heart. Which coronary distribution/anatomical
relation best explains PVCs originating from this surface?
