ECG INTERPRETATION & CARDIAC RHYTHM ANALYSIS
SHARP EKG
TEST BANK
A comprehensive study guide covering cardiac
anatomy, EKG fundamentals, all major rhythm
classifications, AV blocks, ischemia and infarction
patterns, pacemaker management, and integrated
clinical scenarios for nursing exam preparation.
250 Verified Questions & Answers
10 Content Domains | 2026/2027 Edition
NURSING EXAM PREPARATION RESOURCE
, SHARP EKG Test Bank | Verified Questions & Answers | 2026/2027
SHARP EKG Test Bank & Study Guide
Verified Questions & Answers 2026/2027
Comprehensive ECG Interpretation and Cardiac Rhythm Analysis
250 Multiple Choice Questions | Grade A Verified
Section 1: Cardiac Anatomy and Physiology (Q1-Q35)
Section 2: EKG Fundamentals and Lead Placement (Q36-Q65)
Section 3: Sinus Rhythms (Q66-Q85)
Section 4: Atrial Rhythms (Q86-Q105)
Section 5: Junctional Rhythms (Q106-Q120)
Section 6: Ventricular Rhythms (Q121-Q145)
Section 7: AV Blocks (Q146-Q175)
Section 8: Ischemia, Injury, and Infarction (Q176-Q205)
Section 9: Pacemakers and Artificial Rhythms (Q206-Q220)
Section 10: Clinical Scenarios (Q221-Q250)
Cardiac Anatomy & Physiology
Q1. The sinoatrial (SA) node is located in which chamber of the heart?
A. Right atrium near the opening of the superior vena cava [CORRECT]
B. Left atrium near the opening of the pulmonary vein
C. Right ventricle near the interventricular septum
D. Left ventricle near the aortic valve
Correct Answer: A
Rationale: The SA node, often called the heart's natural pacemaker, is located in the upper wall of the right atrium near the opening of
the superior vena cava. It initiates the electrical impulse that begins each normal heartbeat. This strategic location allows the impulse to
spread rapidly through the atria.
Q2. What is the normal intrinsic firing rate of the SA node?
A. 40-60 impulses per minute
B. 60-100 impulses per minute [CORRECT]
C. 20-40 impulses per minute
D. 100-150 impulses per minute
Correct Answer: B
Rationale: The SA node normally fires at a rate of 60-100 impulses per minute, establishing the normal sinus rhythm. If the SA node
fails, secondary pacemakers take over at their own slower intrinsic rates. The AV node fires at 40-60 bpm and ventricular pacemakers at
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, SHARP EKG Test Bank | Verified Questions & Answers | 2026/2027
20-40 bpm.
Q3. Which structure is responsible for delaying the electrical impulse at the AV junction?
A. Bundle of His
B. SA node
C. AV node [CORRECT]
D. Purkinje fibers
Correct Answer: C
Rationale: The AV node intentionally delays the electrical impulse by approximately 0.04-0.11 seconds, allowing the atria to complete
contraction before ventricular depolarization. This essential delay is reflected as the PR interval on the EKG.
Q4. The left anterior descending (LAD) coronary artery supplies blood primarily to which area of the heart?
A. Lateral wall of the left ventricle
B. Anterior wall of the left ventricle and anterior two-thirds of the interventricular septum [CORRECT]
C. Inferior wall of the left ventricle
D. Right atrium and right ventricle
Correct Answer: B
Rationale: The LAD, often called the 'widow maker' artery, supplies the anterior wall of the left ventricle and the anterior two-thirds of
the interventricular septum. Occlusion of this artery can cause extensive anterior myocardial infarction. It is a major branch of the left
main coronary artery.
Q5. Which coronary artery supplies the inferior wall of the left ventricle?
A. Left anterior descending artery
B. Circumflex artery
C. Right coronary artery (RCA) [CORRECT]
D. Left main coronary artery
Correct Answer: C
Rationale: In most individuals (about 85% of the population), the RCA supplies the inferior wall of the left ventricle along with the right
atrium and right ventricle. This is referred to as right dominance. The posterior descending artery, a branch of the RCA in dominant
hearts, supplies the inferior wall.
Q6. What is the primary function of the pericardium?
A. To generate electrical impulses for the heartbeat
B. To pump blood to the systemic circulation
C. To protect the heart and reduce friction during cardiac movement [CORRECT]
D. To regulate blood pressure through the renin-angiotensin system
Correct Answer: C
Rationale: The pericardium is a fibrous sac that encloses the heart and the roots of the great vessels. It contains a small amount of
pericardial fluid that lubricates the heart's surface, reducing friction as the heart beats. It also provides protection and anchors the heart
within the mediastinum.
Q7. The bundle of His is located in which anatomical structure?
A. Left atrial wall
B. Interventricular septum [CORRECT]
C. Right atrial appendage
D. Superior vena cava
Correct Answer: B
Rationale: The bundle of His, also known as the atrioventricular bundle, travels through the interventricular septum after emerging from
the AV node. It divides into the right and left bundle branches that conduct impulses to the respective ventricles. Its location in the septum
allows rapid and coordinated ventricular depolarization.
Q8. Which layer of the heart wall is responsible for the heart's contractile ability?
A. Epicardium
B. Myocardium [CORRECT]
C. Endocardium
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, SHARP EKG Test Bank | Verified Questions & Answers | 2026/2027
D. Pericardium
Correct Answer: B
Rationale: The myocardium is the thick, muscular middle layer of the heart wall composed of cardiac muscle cells. It is responsible for
the heart's ability to contract and pump blood. The myocardium of the left ventricle is significantly thicker than the right because it must
generate sufficient pressure to pump blood through the systemic circulation.
Q9. What is the intrinsic firing rate of the AV node when it acts as a pacemaker?
A. 60-100 impulses per minute
B. 40-60 impulses per minute [CORRECT]
C. 20-40 impulses per minute
D. 10-20 impulses per minute
Correct Answer: B
Rationale: The AV node has an intrinsic firing rate of 40-60 impulses per minute. If the SA node fails and the AV node takes over as the
primary pacemaker, a junctional rhythm at this rate will result. This slower rate underscores the hierarchical nature of the cardiac
conduction system's pacemaker sites.
Q10. The mitral (bicuspid) valve is located between which two cardiac structures?
A. Right atrium and right ventricle
B. Left atrium and left ventricle [CORRECT]
C. Left ventricle and aorta
D. Right ventricle and pulmonary artery
Correct Answer: B
Rationale: The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. It prevents the
backflow of blood from the left ventricle into the left atrium during ventricular systole. It has two leaflets (anterior and posterior) attached
to papillary muscles by chordae tendineae.
Q11. Which chamber of the heart has the thickest myocardial wall?
A. Right atrium
B. Left atrium
C. Right ventricle
D. Left ventricle [CORRECT]
Correct Answer: D
Rationale: The left ventricle has the thickest myocardial wall because it must generate enough pressure to pump blood through the entire
systemic circulation. The right ventricle wall is thinner since it only needs to pump blood to the nearby pulmonary circulation. This
difference in wall thickness is clearly visible on echocardiography.
Q12. The Purkinje fibers have an intrinsic firing rate of approximately:
A. 60-100 impulses per minute
B. 40-60 impulses per minute
C. 20-40 impulses per minute [CORRECT]
D. Less than 20 impulses per minute
Correct Answer: C
Rationale: Purkinje fibers are the terminal branches of the conduction system and have the slowest intrinsic firing rate at 20-40 impulses
per minute. They are the last line of defense for maintaining a heartbeat if higher pacemakers fail. Rhythms originating from Purkinje
fibers are called idioventricular rhythms.
Q13. Which vessel drains deoxygenated blood from the myocardium?
A. Aorta
B. Pulmonary veins
C. Coronary sinus [CORRECT]
D. Superior vena cava
Correct Answer: C
Rationale: The coronary sinus is a large vein on the posterior aspect of the heart that collects deoxygenated blood from the myocardium
through the cardiac veins. It empties into the right atrium. Most of the heart's venous drainage passes through the coronary sinus before
returning to the right atrium.
Page 3
SHARP EKG
TEST BANK
A comprehensive study guide covering cardiac
anatomy, EKG fundamentals, all major rhythm
classifications, AV blocks, ischemia and infarction
patterns, pacemaker management, and integrated
clinical scenarios for nursing exam preparation.
250 Verified Questions & Answers
10 Content Domains | 2026/2027 Edition
NURSING EXAM PREPARATION RESOURCE
, SHARP EKG Test Bank | Verified Questions & Answers | 2026/2027
SHARP EKG Test Bank & Study Guide
Verified Questions & Answers 2026/2027
Comprehensive ECG Interpretation and Cardiac Rhythm Analysis
250 Multiple Choice Questions | Grade A Verified
Section 1: Cardiac Anatomy and Physiology (Q1-Q35)
Section 2: EKG Fundamentals and Lead Placement (Q36-Q65)
Section 3: Sinus Rhythms (Q66-Q85)
Section 4: Atrial Rhythms (Q86-Q105)
Section 5: Junctional Rhythms (Q106-Q120)
Section 6: Ventricular Rhythms (Q121-Q145)
Section 7: AV Blocks (Q146-Q175)
Section 8: Ischemia, Injury, and Infarction (Q176-Q205)
Section 9: Pacemakers and Artificial Rhythms (Q206-Q220)
Section 10: Clinical Scenarios (Q221-Q250)
Cardiac Anatomy & Physiology
Q1. The sinoatrial (SA) node is located in which chamber of the heart?
A. Right atrium near the opening of the superior vena cava [CORRECT]
B. Left atrium near the opening of the pulmonary vein
C. Right ventricle near the interventricular septum
D. Left ventricle near the aortic valve
Correct Answer: A
Rationale: The SA node, often called the heart's natural pacemaker, is located in the upper wall of the right atrium near the opening of
the superior vena cava. It initiates the electrical impulse that begins each normal heartbeat. This strategic location allows the impulse to
spread rapidly through the atria.
Q2. What is the normal intrinsic firing rate of the SA node?
A. 40-60 impulses per minute
B. 60-100 impulses per minute [CORRECT]
C. 20-40 impulses per minute
D. 100-150 impulses per minute
Correct Answer: B
Rationale: The SA node normally fires at a rate of 60-100 impulses per minute, establishing the normal sinus rhythm. If the SA node
fails, secondary pacemakers take over at their own slower intrinsic rates. The AV node fires at 40-60 bpm and ventricular pacemakers at
Page 1
, SHARP EKG Test Bank | Verified Questions & Answers | 2026/2027
20-40 bpm.
Q3. Which structure is responsible for delaying the electrical impulse at the AV junction?
A. Bundle of His
B. SA node
C. AV node [CORRECT]
D. Purkinje fibers
Correct Answer: C
Rationale: The AV node intentionally delays the electrical impulse by approximately 0.04-0.11 seconds, allowing the atria to complete
contraction before ventricular depolarization. This essential delay is reflected as the PR interval on the EKG.
Q4. The left anterior descending (LAD) coronary artery supplies blood primarily to which area of the heart?
A. Lateral wall of the left ventricle
B. Anterior wall of the left ventricle and anterior two-thirds of the interventricular septum [CORRECT]
C. Inferior wall of the left ventricle
D. Right atrium and right ventricle
Correct Answer: B
Rationale: The LAD, often called the 'widow maker' artery, supplies the anterior wall of the left ventricle and the anterior two-thirds of
the interventricular septum. Occlusion of this artery can cause extensive anterior myocardial infarction. It is a major branch of the left
main coronary artery.
Q5. Which coronary artery supplies the inferior wall of the left ventricle?
A. Left anterior descending artery
B. Circumflex artery
C. Right coronary artery (RCA) [CORRECT]
D. Left main coronary artery
Correct Answer: C
Rationale: In most individuals (about 85% of the population), the RCA supplies the inferior wall of the left ventricle along with the right
atrium and right ventricle. This is referred to as right dominance. The posterior descending artery, a branch of the RCA in dominant
hearts, supplies the inferior wall.
Q6. What is the primary function of the pericardium?
A. To generate electrical impulses for the heartbeat
B. To pump blood to the systemic circulation
C. To protect the heart and reduce friction during cardiac movement [CORRECT]
D. To regulate blood pressure through the renin-angiotensin system
Correct Answer: C
Rationale: The pericardium is a fibrous sac that encloses the heart and the roots of the great vessels. It contains a small amount of
pericardial fluid that lubricates the heart's surface, reducing friction as the heart beats. It also provides protection and anchors the heart
within the mediastinum.
Q7. The bundle of His is located in which anatomical structure?
A. Left atrial wall
B. Interventricular septum [CORRECT]
C. Right atrial appendage
D. Superior vena cava
Correct Answer: B
Rationale: The bundle of His, also known as the atrioventricular bundle, travels through the interventricular septum after emerging from
the AV node. It divides into the right and left bundle branches that conduct impulses to the respective ventricles. Its location in the septum
allows rapid and coordinated ventricular depolarization.
Q8. Which layer of the heart wall is responsible for the heart's contractile ability?
A. Epicardium
B. Myocardium [CORRECT]
C. Endocardium
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, SHARP EKG Test Bank | Verified Questions & Answers | 2026/2027
D. Pericardium
Correct Answer: B
Rationale: The myocardium is the thick, muscular middle layer of the heart wall composed of cardiac muscle cells. It is responsible for
the heart's ability to contract and pump blood. The myocardium of the left ventricle is significantly thicker than the right because it must
generate sufficient pressure to pump blood through the systemic circulation.
Q9. What is the intrinsic firing rate of the AV node when it acts as a pacemaker?
A. 60-100 impulses per minute
B. 40-60 impulses per minute [CORRECT]
C. 20-40 impulses per minute
D. 10-20 impulses per minute
Correct Answer: B
Rationale: The AV node has an intrinsic firing rate of 40-60 impulses per minute. If the SA node fails and the AV node takes over as the
primary pacemaker, a junctional rhythm at this rate will result. This slower rate underscores the hierarchical nature of the cardiac
conduction system's pacemaker sites.
Q10. The mitral (bicuspid) valve is located between which two cardiac structures?
A. Right atrium and right ventricle
B. Left atrium and left ventricle [CORRECT]
C. Left ventricle and aorta
D. Right ventricle and pulmonary artery
Correct Answer: B
Rationale: The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. It prevents the
backflow of blood from the left ventricle into the left atrium during ventricular systole. It has two leaflets (anterior and posterior) attached
to papillary muscles by chordae tendineae.
Q11. Which chamber of the heart has the thickest myocardial wall?
A. Right atrium
B. Left atrium
C. Right ventricle
D. Left ventricle [CORRECT]
Correct Answer: D
Rationale: The left ventricle has the thickest myocardial wall because it must generate enough pressure to pump blood through the entire
systemic circulation. The right ventricle wall is thinner since it only needs to pump blood to the nearby pulmonary circulation. This
difference in wall thickness is clearly visible on echocardiography.
Q12. The Purkinje fibers have an intrinsic firing rate of approximately:
A. 60-100 impulses per minute
B. 40-60 impulses per minute
C. 20-40 impulses per minute [CORRECT]
D. Less than 20 impulses per minute
Correct Answer: C
Rationale: Purkinje fibers are the terminal branches of the conduction system and have the slowest intrinsic firing rate at 20-40 impulses
per minute. They are the last line of defense for maintaining a heartbeat if higher pacemakers fail. Rhythms originating from Purkinje
fibers are called idioventricular rhythms.
Q13. Which vessel drains deoxygenated blood from the myocardium?
A. Aorta
B. Pulmonary veins
C. Coronary sinus [CORRECT]
D. Superior vena cava
Correct Answer: C
Rationale: The coronary sinus is a large vein on the posterior aspect of the heart that collects deoxygenated blood from the myocardium
through the cardiac veins. It empties into the right atrium. Most of the heart's venous drainage passes through the coronary sinus before
returning to the right atrium.
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