SHARP ECG Test Preparation
Rhythm Interpretation Practice Questions and
Study Guide
Edition
150 Practice Questions Aligned with
SHARP ECG Certification Standards | AACN ECG Competencies | AHA/ACLS Rhythm Interpretation
Guidelines (2026/2027)
Cognitive Distribution: 25% Recall · 50% Application · 25% Analysis
Question Style: 75% Scenario-Based · 25% Direct Knowledge
Includes: 30 Rhythm Strip Interpretation Questions · 15 12-Lead/Ischemia-Infarction Questions · 10
Pacemaker/Artifact Questions
ECG & Rhythm Interpretation Certification Series | SHARP ECG Standards
,SHARP ECG Test Prep 2026/2027 Rhythm Interpretation Practice
About This Study Guide
This comprehensive 150-question certification examination preparation guide is designed for healthcare
professionals pursuing the SHARP (Society for Healthcare Advancement and Resource Professionals) ECG
Certification. Each question is aligned with SHARP ECG Certification Standards, AACN ECG Competencies, and
AHA/ACLS Rhythm Interpretation Guidelines (2026/2027 edition).
The exam is structured into nine sections covering cardiac anatomy, physiology, and electrophysiology; ECG
fundamentals and waveform analysis; sinus rhythms and variations; atrial dysrhythmias; junctional dysrhythmias;
ventricular dysrhythmias; atrioventricular blocks and conduction defects; pacemaker rhythms and artifacts; and
12-lead ECG, ischemia, injury, and infarction. Cognitive complexity follows the SHARP ECG blueprint:
approximately 25% recall (knowledge), 50% application (rhythm strip interpretation, protocol application), and 25%
analysis (clinical correlation, management decisions). Approximately 75% of questions are scenario-based,
mirroring real-world rhythm strip interpretation and clinical decision-making.
Each question is followed by four options (A-D) with exactly one correct answer marked *[CORRECT]*, a
'Correct Answer' line, and a 2-4 sentence rationale citing the governing SHARP ECG certification standard, AACN
ECG competency, and AHA/ACLS rhythm interpretation reference. Use this guide as both a self-assessment tool
and a structured study reference for SHARP ECG test preparation.
Section 1: Cardiac Anatomy, Physiology, & Electrophysiology
Cardiac chambers, valves, coronary arteries, conduction system (SA node, AV node, bundle of His, branches,
Purkinje fibers), action potentials, preload/afterload/contractility, refractory periods — 15 questions.
Q1. A nurse is explaining the cardiac conduction system to a patient. Which sequence correctly describes
the normal pathway of electrical impulses through the heart?
A. AV node → SA node → bundle of His → Purkinje fibers → bundle branches.
B. SA node → AV node → bundle of His → bundle branches → Purkinje fibers. *[CORRECT]*
C. Purkinje fibers → bundle branches → bundle of His → AV node → SA node.
D. SA node → Purkinje fibers → AV node → bundle of His → bundle branches.
Correct Answer: B
Rationale: The normal electrical pathway begins at the SA node (primary pacemaker, intrinsic rate 60-100 bpm),
proceeds to the AV node (delay of 0.04 sec allowing atrial kick), then to the bundle of His, bundle branches, and
finally the Purkinje fibers for ventricular depolarization. Options A, C, and D misorder the conduction sequence and
would not produce a normal sinus rhythm.
Aligned with SHARP ECG Standards, AACN ECG Competencies, and AHA/ACLS Rhythm Guidelines Page 2
,SHARP ECG Test Prep 2026/2027 Rhythm Interpretation Practice
Q2. A patient with an inferior wall STEMI is most likely to have occlusion in which coronary artery?
A. Left anterior descending (LAD) artery.
B. Right coronary artery (RCA). *[CORRECT]*
C. Left circumflex (LCx) artery.
D. Left main coronary artery.
Correct Answer: B
Rationale: The right coronary artery (RCA) supplies the inferior wall of the left ventricle, the SA node (in ~60% of
people), the AV node (in ~90%), and the right ventricle. Inferior STEMI (ST elevation in II, III, aVF) is typically
caused by RCA occlusion. The LAD supplies the anterior wall (Option A), the LCx supplies the lateral wall (Option
C), and the left main supplies both (Option D, catastrophic).
Q3. Phase 0 of the ventricular cardiac action potential corresponds to which electrophysiological event?
A. Rapid repolarization due to potassium efflux.
B. Slow calcium influx causing the plateau.
C. Rapid depolarization due to fast sodium influx. *[CORRECT]*
D. Resting membrane potential restored.
Correct Answer: C
Rationale: Phase 0 of the ventricular myocyte action potential is rapid depolarization caused by fast sodium influx
through Na+ channels. Phase 2 (Option B) is the plateau from slow Ca2+ influx. Phase 3 (Option A) is rapid
repolarization from K+ efflux. Phase 4 (Option D) is resting membrane potential. This distinction is critical for
understanding antiarrhythmic drug mechanisms (Class I drugs block sodium channels).
Q4. A patient in the ICU has a blood pressure of 90/50 mmHg, heart rate of 110, and stroke volume of 40
mL. Cardiac output is approximately:
A. 2.4 L/min (insufficient for tissue perfusion).
B. 4.4 L/min (low-normal). *[CORRECT]*
C. 6.0 L/min (normal).
D. 8.0 L/min (elevated).
Correct Answer: B
Rationale: Cardiac output (CO) = Heart Rate × Stroke Volume (CO = HR × SV). 110 × 40 mL = 4,400 mL/min or
4.4 L/min. While the value is technically in the low-normal range, the clinical picture (hypotension, tachycardia)
reflects compensation for low stroke volume. Option A miscalculates; Option C and D are incorrect given the inputs.
Aligned with SHARP ECG Standards, AACN ECG Competencies, and AHA/ACLS Rhythm Guidelines Page 3
, SHARP ECG Test Prep 2026/2027 Rhythm Interpretation Practice
Q5. Which of the following best defines 'preload'?
A. The resistance the left ventricle must overcome to eject blood.
B. The degree of ventricular stretch at end-diastole, determined by venous return. *[CORRECT]*
C. The force of myocardial contraction independent of loading.
D. The volume of blood ejected per beat.
Correct Answer: B
Rationale: Preload is the degree of ventricular stretch at end-diastole, determined by venous return (the volume of
blood filling the ventricle before contraction). Per the Frank-Starling law, increased preload increases stroke volume
up to a point. Option A defines afterload. Option C defines contractility. Option D defines stroke volume.
Q6. A patient with aortic stenosis develops increased myocardial workload. Which hemodynamic
parameter is primarily elevated in this condition?
A. Preload.
B. Afterload. *[CORRECT]*
C. Contractility.
D. Heart rate.
Correct Answer: B
Rationale: Aortic stenosis creates a fixed obstruction to left ventricular outflow, significantly increasing afterload
(the resistance the LV must overcome to eject blood). The LV compensates with concentric hypertrophy. Preload
(Option A), contractility (Option C), and heart rate (Option D) are not the primary hemodynamic change in aortic
stenosis.
Q7. The absolute refractory period of the cardiac action potential corresponds to which portion of the
ECG?
A. The P wave.
B. The PR interval.
C. The QRS complex and the initial portion of the ST segment (from QRS onset through approximately the
first half of the T wave). *[CORRECT]*
D. The T wave only.
Correct Answer: C
Rationale: The absolute refractory period corresponds to the QRS complex through approximately the first half of
the T wave. During this time, no stimulus — however strong — can generate a new action potential. This protects the
heart from fatal dysrhythmias by preventing sustained tetany. The relative refractory period corresponds to the
downstroke of the T wave (the 'vulnerable period' where R-on-T can precipitate V-Tach/V-Fib).
Aligned with SHARP ECG Standards, AACN ECG Competencies, and AHA/ACLS Rhythm Guidelines Page 4
Rhythm Interpretation Practice Questions and
Study Guide
Edition
150 Practice Questions Aligned with
SHARP ECG Certification Standards | AACN ECG Competencies | AHA/ACLS Rhythm Interpretation
Guidelines (2026/2027)
Cognitive Distribution: 25% Recall · 50% Application · 25% Analysis
Question Style: 75% Scenario-Based · 25% Direct Knowledge
Includes: 30 Rhythm Strip Interpretation Questions · 15 12-Lead/Ischemia-Infarction Questions · 10
Pacemaker/Artifact Questions
ECG & Rhythm Interpretation Certification Series | SHARP ECG Standards
,SHARP ECG Test Prep 2026/2027 Rhythm Interpretation Practice
About This Study Guide
This comprehensive 150-question certification examination preparation guide is designed for healthcare
professionals pursuing the SHARP (Society for Healthcare Advancement and Resource Professionals) ECG
Certification. Each question is aligned with SHARP ECG Certification Standards, AACN ECG Competencies, and
AHA/ACLS Rhythm Interpretation Guidelines (2026/2027 edition).
The exam is structured into nine sections covering cardiac anatomy, physiology, and electrophysiology; ECG
fundamentals and waveform analysis; sinus rhythms and variations; atrial dysrhythmias; junctional dysrhythmias;
ventricular dysrhythmias; atrioventricular blocks and conduction defects; pacemaker rhythms and artifacts; and
12-lead ECG, ischemia, injury, and infarction. Cognitive complexity follows the SHARP ECG blueprint:
approximately 25% recall (knowledge), 50% application (rhythm strip interpretation, protocol application), and 25%
analysis (clinical correlation, management decisions). Approximately 75% of questions are scenario-based,
mirroring real-world rhythm strip interpretation and clinical decision-making.
Each question is followed by four options (A-D) with exactly one correct answer marked *[CORRECT]*, a
'Correct Answer' line, and a 2-4 sentence rationale citing the governing SHARP ECG certification standard, AACN
ECG competency, and AHA/ACLS rhythm interpretation reference. Use this guide as both a self-assessment tool
and a structured study reference for SHARP ECG test preparation.
Section 1: Cardiac Anatomy, Physiology, & Electrophysiology
Cardiac chambers, valves, coronary arteries, conduction system (SA node, AV node, bundle of His, branches,
Purkinje fibers), action potentials, preload/afterload/contractility, refractory periods — 15 questions.
Q1. A nurse is explaining the cardiac conduction system to a patient. Which sequence correctly describes
the normal pathway of electrical impulses through the heart?
A. AV node → SA node → bundle of His → Purkinje fibers → bundle branches.
B. SA node → AV node → bundle of His → bundle branches → Purkinje fibers. *[CORRECT]*
C. Purkinje fibers → bundle branches → bundle of His → AV node → SA node.
D. SA node → Purkinje fibers → AV node → bundle of His → bundle branches.
Correct Answer: B
Rationale: The normal electrical pathway begins at the SA node (primary pacemaker, intrinsic rate 60-100 bpm),
proceeds to the AV node (delay of 0.04 sec allowing atrial kick), then to the bundle of His, bundle branches, and
finally the Purkinje fibers for ventricular depolarization. Options A, C, and D misorder the conduction sequence and
would not produce a normal sinus rhythm.
Aligned with SHARP ECG Standards, AACN ECG Competencies, and AHA/ACLS Rhythm Guidelines Page 2
,SHARP ECG Test Prep 2026/2027 Rhythm Interpretation Practice
Q2. A patient with an inferior wall STEMI is most likely to have occlusion in which coronary artery?
A. Left anterior descending (LAD) artery.
B. Right coronary artery (RCA). *[CORRECT]*
C. Left circumflex (LCx) artery.
D. Left main coronary artery.
Correct Answer: B
Rationale: The right coronary artery (RCA) supplies the inferior wall of the left ventricle, the SA node (in ~60% of
people), the AV node (in ~90%), and the right ventricle. Inferior STEMI (ST elevation in II, III, aVF) is typically
caused by RCA occlusion. The LAD supplies the anterior wall (Option A), the LCx supplies the lateral wall (Option
C), and the left main supplies both (Option D, catastrophic).
Q3. Phase 0 of the ventricular cardiac action potential corresponds to which electrophysiological event?
A. Rapid repolarization due to potassium efflux.
B. Slow calcium influx causing the plateau.
C. Rapid depolarization due to fast sodium influx. *[CORRECT]*
D. Resting membrane potential restored.
Correct Answer: C
Rationale: Phase 0 of the ventricular myocyte action potential is rapid depolarization caused by fast sodium influx
through Na+ channels. Phase 2 (Option B) is the plateau from slow Ca2+ influx. Phase 3 (Option A) is rapid
repolarization from K+ efflux. Phase 4 (Option D) is resting membrane potential. This distinction is critical for
understanding antiarrhythmic drug mechanisms (Class I drugs block sodium channels).
Q4. A patient in the ICU has a blood pressure of 90/50 mmHg, heart rate of 110, and stroke volume of 40
mL. Cardiac output is approximately:
A. 2.4 L/min (insufficient for tissue perfusion).
B. 4.4 L/min (low-normal). *[CORRECT]*
C. 6.0 L/min (normal).
D. 8.0 L/min (elevated).
Correct Answer: B
Rationale: Cardiac output (CO) = Heart Rate × Stroke Volume (CO = HR × SV). 110 × 40 mL = 4,400 mL/min or
4.4 L/min. While the value is technically in the low-normal range, the clinical picture (hypotension, tachycardia)
reflects compensation for low stroke volume. Option A miscalculates; Option C and D are incorrect given the inputs.
Aligned with SHARP ECG Standards, AACN ECG Competencies, and AHA/ACLS Rhythm Guidelines Page 3
, SHARP ECG Test Prep 2026/2027 Rhythm Interpretation Practice
Q5. Which of the following best defines 'preload'?
A. The resistance the left ventricle must overcome to eject blood.
B. The degree of ventricular stretch at end-diastole, determined by venous return. *[CORRECT]*
C. The force of myocardial contraction independent of loading.
D. The volume of blood ejected per beat.
Correct Answer: B
Rationale: Preload is the degree of ventricular stretch at end-diastole, determined by venous return (the volume of
blood filling the ventricle before contraction). Per the Frank-Starling law, increased preload increases stroke volume
up to a point. Option A defines afterload. Option C defines contractility. Option D defines stroke volume.
Q6. A patient with aortic stenosis develops increased myocardial workload. Which hemodynamic
parameter is primarily elevated in this condition?
A. Preload.
B. Afterload. *[CORRECT]*
C. Contractility.
D. Heart rate.
Correct Answer: B
Rationale: Aortic stenosis creates a fixed obstruction to left ventricular outflow, significantly increasing afterload
(the resistance the LV must overcome to eject blood). The LV compensates with concentric hypertrophy. Preload
(Option A), contractility (Option C), and heart rate (Option D) are not the primary hemodynamic change in aortic
stenosis.
Q7. The absolute refractory period of the cardiac action potential corresponds to which portion of the
ECG?
A. The P wave.
B. The PR interval.
C. The QRS complex and the initial portion of the ST segment (from QRS onset through approximately the
first half of the T wave). *[CORRECT]*
D. The T wave only.
Correct Answer: C
Rationale: The absolute refractory period corresponds to the QRS complex through approximately the first half of
the T wave. During this time, no stimulus — however strong — can generate a new action potential. This protects the
heart from fatal dysrhythmias by preventing sustained tetany. The relative refractory period corresponds to the
downstroke of the T wave (the 'vulnerable period' where R-on-T can precipitate V-Tach/V-Fib).
Aligned with SHARP ECG Standards, AACN ECG Competencies, and AHA/ACLS Rhythm Guidelines Page 4
