,CHAPTER LIST
Chapter 1: Normal Cardiac Structure and Function
Chapter 2: The Cardiac Cycle — Mechanisms of Heart Sounds and
Murmurs
Chapter 3: Cardiac Imaging and Hemodynamic Assessment
Chapter 4: The Electrocardiogram
Chapter 5: Atherosclerosis
Chapter 6: Ischemic Heart Disease
Chapter 7: Acute Coronary Syndromes
Chapter 8: Valvular Heart Disease
Chapter 9: Heart Failure
Chapter 10: The Cardiomyopathies
Chapter 11: Mechanisms of Cardiac Arrhythmias
Chapter 12: Clinical Aspects of Cardiac Arrhythmias
Chapter 13: Hypertension
Chapter 14: Diseases of the Pericardium
Chapter 15: Diseases of the Peripheral Vasculature
Chapter 16: Congenital Heart Disease
Chapter 17: Cardiovascular Drugs
,CHAPTER 1: Normal Cardiac Structure and Function
Q1. Which chamber of the heart has the thickest myocardium under normal physiologic
conditions and why?
A. Right atrium – because it receives systemic venous blood
B. Left atrium – because it pumps to the left ventricle
C. Right ventricle – because it pumps against pulmonary resistance
D. Left ventricle – because it pumps against systemic vascular resistance
Answer: D
Rationale: The left ventricle must generate high pressures to overcome systemic
vascular resistance, so it has the thickest myocardial wall. In contrast, the right ventricle
pumps against lower pulmonary pressures.
Key words: left ventricle, myocardial thickness, systemic resistance, cardiac anatomy
Q2. Which coronary artery primarily supplies the sinoatrial (SA) node in the majority of
individuals?
A. Left anterior descending artery
B. Right coronary artery
C. Circumflex artery
D. Posterior descending artery
Answer: B
Rationale: In approximately 60% of individuals, the SA node is supplied by the right
coronary artery. This is clinically relevant because RCA occlusion can cause
bradyarrhythmias.
Key words: SA node, coronary artery supply, right coronary artery, conduction system
Q3. The atrioventricular (AV) node delays conduction primarily to:
A. Allow atrial contraction to complete before ventricular contraction
B. Prevent atrial fibrillation
,C. Increase cardiac output by increasing heart rate
D. Synchronize ventricular and pulmonary contractions
Answer: A
Rationale: The AV node imposes a physiologic delay (~0.1 s) to allow atrial contraction
to complete ventricular filling before the ventricles contract, optimizing stroke volume.
Key words: AV node, conduction delay, atrial contraction, stroke volume
Q4. During early diastole, ventricular filling is mainly driven by:
A. Ventricular systole
B. Atrial contraction
C. Passive pressure gradient from atrium to ventricle
D. AV nodal depolarization
Answer: C
Rationale: Most ventricular filling occurs passively due to a pressure gradient from atria
to ventricles during early diastole. Atrial contraction contributes only in late diastole.
Key words: diastole, ventricular filling, atrial pressure, cardiac cycle
Q5. Preload is best described as:
A. Afterload during systole
B. Ventricular wall stress at end-diastole
C. Heart rate multiplied by stroke volume
D. Aortic pressure during diastole
Answer: B
Rationale: Preload refers to ventricular wall stress at the end of diastole, reflecting the
degree of stretch of myocardial fibers before contraction.
Key words: preload, wall stress, Frank-Starling law, end-diastolic volume
,Q6. Which myocardial layer contains the contractile fibers responsible for systolic
ejection?
A. Epicardium
B. Endocardium
C. Myocardium
D. Pericardium
Answer: C
Rationale: The myocardium, especially the middle and inner layers of ventricular walls,
contains contractile myocytes responsible for generating systolic pressure.
Key words: myocardium, contraction, ventricular ejection, cardiac layers
Q7. The Frank-Starling mechanism explains:
A. The inverse relationship between heart rate and stroke volume
B. How increased ventricular filling leads to increased stroke volume
C. The regulation of cardiac output by sympathetic tone
D. The effect of afterload on myocardial oxygen consumption
Answer: B
Rationale: The Frank-Starling mechanism states that increased end-diastolic volume
stretches myocardial fibers, enhancing contractile force and stroke volume, up to a
physiologic limit.
Key words: Frank-Starling, stroke volume, preload, contractility
Q8. Cardiac output is determined by:
A. Heart rate × stroke volume
B. Preload × afterload
C. Ventricular wall thickness × heart rate
D. Systemic vascular resistance × ejection fraction
Answer: A
Rationale: Cardiac output (CO) is defined as the product of heart rate (HR) and stroke
volume (SV). SV is influenced by preload, afterload, and contractility.
, Key words: cardiac output, stroke volume, heart rate, CO formula
Q9. Which statement best describes afterload?
A. The pressure the ventricles must overcome to eject blood
B. End-diastolic ventricular volume
C. Atrial contribution to ventricular filling
D. Rate of myocardial depolarization
Answer: A
Rationale: Afterload represents the force or pressure the ventricles must overcome to
eject blood during systole, primarily determined by arterial pressure and systemic
vascular resistance.
Key words: afterload, systole, ventricular ejection, vascular resistance
Q10. Gap junctions in cardiac myocytes are critical because they:
A. Provide structural support to valves
B. Allow synchronized electrical conduction between cells
C. Store calcium for contraction
D. Maintain pericardial integrity
Answer: B
Rationale: Gap junctions allow rapid passage of ions between myocytes, enabling
coordinated depolarization and synchronous contraction of the heart.
Key words: gap junctions, myocytes, conduction, syncytium
Q11. The ratio of end-systolic volume to end-diastolic volume determines:
A. Ejection fraction
B. Preload
C. Afterload
D. Cardiac output
Answer: A
Chapter 1: Normal Cardiac Structure and Function
Chapter 2: The Cardiac Cycle — Mechanisms of Heart Sounds and
Murmurs
Chapter 3: Cardiac Imaging and Hemodynamic Assessment
Chapter 4: The Electrocardiogram
Chapter 5: Atherosclerosis
Chapter 6: Ischemic Heart Disease
Chapter 7: Acute Coronary Syndromes
Chapter 8: Valvular Heart Disease
Chapter 9: Heart Failure
Chapter 10: The Cardiomyopathies
Chapter 11: Mechanisms of Cardiac Arrhythmias
Chapter 12: Clinical Aspects of Cardiac Arrhythmias
Chapter 13: Hypertension
Chapter 14: Diseases of the Pericardium
Chapter 15: Diseases of the Peripheral Vasculature
Chapter 16: Congenital Heart Disease
Chapter 17: Cardiovascular Drugs
,CHAPTER 1: Normal Cardiac Structure and Function
Q1. Which chamber of the heart has the thickest myocardium under normal physiologic
conditions and why?
A. Right atrium – because it receives systemic venous blood
B. Left atrium – because it pumps to the left ventricle
C. Right ventricle – because it pumps against pulmonary resistance
D. Left ventricle – because it pumps against systemic vascular resistance
Answer: D
Rationale: The left ventricle must generate high pressures to overcome systemic
vascular resistance, so it has the thickest myocardial wall. In contrast, the right ventricle
pumps against lower pulmonary pressures.
Key words: left ventricle, myocardial thickness, systemic resistance, cardiac anatomy
Q2. Which coronary artery primarily supplies the sinoatrial (SA) node in the majority of
individuals?
A. Left anterior descending artery
B. Right coronary artery
C. Circumflex artery
D. Posterior descending artery
Answer: B
Rationale: In approximately 60% of individuals, the SA node is supplied by the right
coronary artery. This is clinically relevant because RCA occlusion can cause
bradyarrhythmias.
Key words: SA node, coronary artery supply, right coronary artery, conduction system
Q3. The atrioventricular (AV) node delays conduction primarily to:
A. Allow atrial contraction to complete before ventricular contraction
B. Prevent atrial fibrillation
,C. Increase cardiac output by increasing heart rate
D. Synchronize ventricular and pulmonary contractions
Answer: A
Rationale: The AV node imposes a physiologic delay (~0.1 s) to allow atrial contraction
to complete ventricular filling before the ventricles contract, optimizing stroke volume.
Key words: AV node, conduction delay, atrial contraction, stroke volume
Q4. During early diastole, ventricular filling is mainly driven by:
A. Ventricular systole
B. Atrial contraction
C. Passive pressure gradient from atrium to ventricle
D. AV nodal depolarization
Answer: C
Rationale: Most ventricular filling occurs passively due to a pressure gradient from atria
to ventricles during early diastole. Atrial contraction contributes only in late diastole.
Key words: diastole, ventricular filling, atrial pressure, cardiac cycle
Q5. Preload is best described as:
A. Afterload during systole
B. Ventricular wall stress at end-diastole
C. Heart rate multiplied by stroke volume
D. Aortic pressure during diastole
Answer: B
Rationale: Preload refers to ventricular wall stress at the end of diastole, reflecting the
degree of stretch of myocardial fibers before contraction.
Key words: preload, wall stress, Frank-Starling law, end-diastolic volume
,Q6. Which myocardial layer contains the contractile fibers responsible for systolic
ejection?
A. Epicardium
B. Endocardium
C. Myocardium
D. Pericardium
Answer: C
Rationale: The myocardium, especially the middle and inner layers of ventricular walls,
contains contractile myocytes responsible for generating systolic pressure.
Key words: myocardium, contraction, ventricular ejection, cardiac layers
Q7. The Frank-Starling mechanism explains:
A. The inverse relationship between heart rate and stroke volume
B. How increased ventricular filling leads to increased stroke volume
C. The regulation of cardiac output by sympathetic tone
D. The effect of afterload on myocardial oxygen consumption
Answer: B
Rationale: The Frank-Starling mechanism states that increased end-diastolic volume
stretches myocardial fibers, enhancing contractile force and stroke volume, up to a
physiologic limit.
Key words: Frank-Starling, stroke volume, preload, contractility
Q8. Cardiac output is determined by:
A. Heart rate × stroke volume
B. Preload × afterload
C. Ventricular wall thickness × heart rate
D. Systemic vascular resistance × ejection fraction
Answer: A
Rationale: Cardiac output (CO) is defined as the product of heart rate (HR) and stroke
volume (SV). SV is influenced by preload, afterload, and contractility.
, Key words: cardiac output, stroke volume, heart rate, CO formula
Q9. Which statement best describes afterload?
A. The pressure the ventricles must overcome to eject blood
B. End-diastolic ventricular volume
C. Atrial contribution to ventricular filling
D. Rate of myocardial depolarization
Answer: A
Rationale: Afterload represents the force or pressure the ventricles must overcome to
eject blood during systole, primarily determined by arterial pressure and systemic
vascular resistance.
Key words: afterload, systole, ventricular ejection, vascular resistance
Q10. Gap junctions in cardiac myocytes are critical because they:
A. Provide structural support to valves
B. Allow synchronized electrical conduction between cells
C. Store calcium for contraction
D. Maintain pericardial integrity
Answer: B
Rationale: Gap junctions allow rapid passage of ions between myocytes, enabling
coordinated depolarization and synchronous contraction of the heart.
Key words: gap junctions, myocytes, conduction, syncytium
Q11. The ratio of end-systolic volume to end-diastolic volume determines:
A. Ejection fraction
B. Preload
C. Afterload
D. Cardiac output
Answer: A
