American Board of Cardiovascular Disease Practice Exam
1. Which ion channel abnormality is most commonly associated with atrial fibrillation?
A. Sodium channel dysfunction
B. Potassium channel dysfunction
C. Calcium channel dysfunction
D. Chloride channel dysfunction
Answer: B
Explanation: Abnormalities in potassium channels can lead to electrical remodeling, a key factor
in atrial fibrillation.
2. In the context of supraventricular tachycardia, which maneuver is most useful in
terminating the rhythm?
A. Carotid massage
B. Deep breathing
C. Valsalva maneuver
D. Coughing
Answer: C
Explanation: The Valsalva maneuver increases vagal tone and can help break reentrant circuits in
supraventricular tachycardia.
3. What is the primary mechanism behind reentrant arrhythmias?
A. Enhanced automaticity
B. Triggered activity
C. Dual pathway conduction
D. Focal ectopic discharge
Answer: C
Explanation: Reentry involves dual pathway conduction that allows a circulating electrical
impulse to re-excite tissue.
4. Which diagnostic tool is most effective in identifying paroxysmal arrhythmias?
A. Standard 12-lead ECG
B. Echocardiography
C. Holter monitor
D. Cardiac MRI
Answer: C
Explanation: A Holter monitor records electrical activity over 24–48 hours, capturing
intermittent arrhythmias that a single ECG might miss.
5. In patients with Wolff-Parkinson-White syndrome, what is the characteristic ECG
finding?
A. Delta wave
B. Prolonged PR interval
C. Q wave abnormality
,D. Inverted T waves
Answer: A
Explanation: The presence of a delta wave indicates pre-excitation of the ventricles via an
accessory pathway.
6. Which medication is most commonly used as a first-line rate control agent in atrial
fibrillation?
A. Amiodarone
B. Beta-blockers
C. Calcium channel blockers
D. Digoxin
Answer: B
Explanation: Beta-blockers are typically used to control the ventricular rate in atrial fibrillation.
7. What is the mechanism of action of class III antiarrhythmic drugs?
A. Sodium channel blockade
B. Beta-adrenergic blockade
C. Potassium channel blockade
D. Calcium channel blockade
Answer: C
Explanation: Class III agents primarily work by blocking potassium channels, prolonging
repolarization.
8. Which condition predisposes a patient to torsades de pointes?
A. Hyperkalemia
B. QT prolongation
C. ST elevation
D. Short PR interval
Answer: B
Explanation: QT prolongation is a well-known risk factor for developing the polymorphic
ventricular tachycardia known as torsades de pointes.
9. The “holiday heart syndrome” is most often associated with which of the following?
A. Chronic alcohol abuse
B. Acute alcohol binge
C. Drug overdose
D. Hyperthyroidism
Answer: B
Explanation: Holiday heart syndrome refers to atrial fibrillation precipitated by an acute alcohol
binge, even in individuals without underlying heart disease.
10. Which electrophysiologic property is critical for sustaining reentrant arrhythmias?
A. Rapid conduction velocity
B. Prolonged refractoriness
C. Unidirectional block
D. Uniform excitability
,Answer: C
Explanation: A unidirectional block allows impulses to reenter previously excited tissue,
sustaining reentrant arrhythmias.
11. What is the most common cause of ischemic heart disease?
A. Coronary artery spasm
B. Atherosclerosis
C. Vasculitis
D. Embolism
Answer: B
Explanation: Atherosclerosis is the primary cause of coronary artery disease due to plaque
buildup in the coronary arteries.
12. Which risk factor is most strongly linked to the development of coronary artery
disease?
A. Obesity
B. Sedentary lifestyle
C. Smoking
D. Hypercholesterolemia
Answer: D
Explanation: Elevated cholesterol levels lead to atherosclerotic plaque formation and are a major
risk factor for coronary artery disease.
13. What is the purpose of a stress test in the evaluation of coronary artery disease?
A. To assess valvular function
B. To evaluate myocardial perfusion under stress
C. To measure cardiac output at rest
D. To detect arrhythmias
Answer: B
Explanation: Stress tests help to identify areas of the heart that receive inadequate blood flow
during increased demand.
14. Which imaging modality is best for evaluating myocardial perfusion?
A. Echocardiogram
B. CT angiography
C. Nuclear perfusion scan
D. Cardiac MRI
Answer: C
Explanation: A nuclear perfusion scan uses radioactive tracers to assess blood flow to the
myocardium during stress and rest.
15. What does a positive stress test typically indicate in a patient with suspected coronary
artery disease?
A. Normal coronary arteries
B. Presence of coronary ischemia
C. Myocardial hypertrophy
, D. Valvular disease
Answer: B
Explanation: A positive stress test usually reveals areas of myocardial ischemia due to reduced
coronary blood flow.
16. Which lifestyle modification is most effective in reducing coronary artery disease risk?
A. Increased caffeine intake
B. Smoking cessation
C. High protein diet
D. Reduced water consumption
Answer: B
Explanation: Smoking cessation significantly reduces the risk of atherosclerosis and subsequent
coronary artery disease.
17. What is the main goal of percutaneous coronary intervention (PCI) in coronary artery
disease?
A. To replace the valve
B. To restore blood flow
C. To diagnose heart failure
D. To prevent arrhythmias
Answer: B
Explanation: PCI is used to open narrowed coronary arteries and restore adequate blood flow to
the myocardium.
18. Which biomarker is most useful in diagnosing an acute myocardial infarction?
A. C-reactive protein
B. Troponin I
C. Creatinine
D. D-dimer
Answer: B
Explanation: Troponin I is a highly sensitive and specific marker for myocardial injury.
19. In coronary artery disease, which plaque component is most responsible for acute
coronary syndromes?
A. Calcified plaque
B. Stable fibrous plaque
C. Ruptured vulnerable plaque
D. Non-obstructive plaque
Answer: C
Explanation: Ruptured vulnerable plaques with a thin fibrous cap can lead to thrombosis and
acute coronary syndromes.
20. Which antiplatelet agent is commonly used for secondary prevention in coronary artery
disease?
A. Clopidogrel
B. Warfarin
1. Which ion channel abnormality is most commonly associated with atrial fibrillation?
A. Sodium channel dysfunction
B. Potassium channel dysfunction
C. Calcium channel dysfunction
D. Chloride channel dysfunction
Answer: B
Explanation: Abnormalities in potassium channels can lead to electrical remodeling, a key factor
in atrial fibrillation.
2. In the context of supraventricular tachycardia, which maneuver is most useful in
terminating the rhythm?
A. Carotid massage
B. Deep breathing
C. Valsalva maneuver
D. Coughing
Answer: C
Explanation: The Valsalva maneuver increases vagal tone and can help break reentrant circuits in
supraventricular tachycardia.
3. What is the primary mechanism behind reentrant arrhythmias?
A. Enhanced automaticity
B. Triggered activity
C. Dual pathway conduction
D. Focal ectopic discharge
Answer: C
Explanation: Reentry involves dual pathway conduction that allows a circulating electrical
impulse to re-excite tissue.
4. Which diagnostic tool is most effective in identifying paroxysmal arrhythmias?
A. Standard 12-lead ECG
B. Echocardiography
C. Holter monitor
D. Cardiac MRI
Answer: C
Explanation: A Holter monitor records electrical activity over 24–48 hours, capturing
intermittent arrhythmias that a single ECG might miss.
5. In patients with Wolff-Parkinson-White syndrome, what is the characteristic ECG
finding?
A. Delta wave
B. Prolonged PR interval
C. Q wave abnormality
,D. Inverted T waves
Answer: A
Explanation: The presence of a delta wave indicates pre-excitation of the ventricles via an
accessory pathway.
6. Which medication is most commonly used as a first-line rate control agent in atrial
fibrillation?
A. Amiodarone
B. Beta-blockers
C. Calcium channel blockers
D. Digoxin
Answer: B
Explanation: Beta-blockers are typically used to control the ventricular rate in atrial fibrillation.
7. What is the mechanism of action of class III antiarrhythmic drugs?
A. Sodium channel blockade
B. Beta-adrenergic blockade
C. Potassium channel blockade
D. Calcium channel blockade
Answer: C
Explanation: Class III agents primarily work by blocking potassium channels, prolonging
repolarization.
8. Which condition predisposes a patient to torsades de pointes?
A. Hyperkalemia
B. QT prolongation
C. ST elevation
D. Short PR interval
Answer: B
Explanation: QT prolongation is a well-known risk factor for developing the polymorphic
ventricular tachycardia known as torsades de pointes.
9. The “holiday heart syndrome” is most often associated with which of the following?
A. Chronic alcohol abuse
B. Acute alcohol binge
C. Drug overdose
D. Hyperthyroidism
Answer: B
Explanation: Holiday heart syndrome refers to atrial fibrillation precipitated by an acute alcohol
binge, even in individuals without underlying heart disease.
10. Which electrophysiologic property is critical for sustaining reentrant arrhythmias?
A. Rapid conduction velocity
B. Prolonged refractoriness
C. Unidirectional block
D. Uniform excitability
,Answer: C
Explanation: A unidirectional block allows impulses to reenter previously excited tissue,
sustaining reentrant arrhythmias.
11. What is the most common cause of ischemic heart disease?
A. Coronary artery spasm
B. Atherosclerosis
C. Vasculitis
D. Embolism
Answer: B
Explanation: Atherosclerosis is the primary cause of coronary artery disease due to plaque
buildup in the coronary arteries.
12. Which risk factor is most strongly linked to the development of coronary artery
disease?
A. Obesity
B. Sedentary lifestyle
C. Smoking
D. Hypercholesterolemia
Answer: D
Explanation: Elevated cholesterol levels lead to atherosclerotic plaque formation and are a major
risk factor for coronary artery disease.
13. What is the purpose of a stress test in the evaluation of coronary artery disease?
A. To assess valvular function
B. To evaluate myocardial perfusion under stress
C. To measure cardiac output at rest
D. To detect arrhythmias
Answer: B
Explanation: Stress tests help to identify areas of the heart that receive inadequate blood flow
during increased demand.
14. Which imaging modality is best for evaluating myocardial perfusion?
A. Echocardiogram
B. CT angiography
C. Nuclear perfusion scan
D. Cardiac MRI
Answer: C
Explanation: A nuclear perfusion scan uses radioactive tracers to assess blood flow to the
myocardium during stress and rest.
15. What does a positive stress test typically indicate in a patient with suspected coronary
artery disease?
A. Normal coronary arteries
B. Presence of coronary ischemia
C. Myocardial hypertrophy
, D. Valvular disease
Answer: B
Explanation: A positive stress test usually reveals areas of myocardial ischemia due to reduced
coronary blood flow.
16. Which lifestyle modification is most effective in reducing coronary artery disease risk?
A. Increased caffeine intake
B. Smoking cessation
C. High protein diet
D. Reduced water consumption
Answer: B
Explanation: Smoking cessation significantly reduces the risk of atherosclerosis and subsequent
coronary artery disease.
17. What is the main goal of percutaneous coronary intervention (PCI) in coronary artery
disease?
A. To replace the valve
B. To restore blood flow
C. To diagnose heart failure
D. To prevent arrhythmias
Answer: B
Explanation: PCI is used to open narrowed coronary arteries and restore adequate blood flow to
the myocardium.
18. Which biomarker is most useful in diagnosing an acute myocardial infarction?
A. C-reactive protein
B. Troponin I
C. Creatinine
D. D-dimer
Answer: B
Explanation: Troponin I is a highly sensitive and specific marker for myocardial injury.
19. In coronary artery disease, which plaque component is most responsible for acute
coronary syndromes?
A. Calcified plaque
B. Stable fibrous plaque
C. Ruptured vulnerable plaque
D. Non-obstructive plaque
Answer: C
Explanation: Ruptured vulnerable plaques with a thin fibrous cap can lead to thrombosis and
acute coronary syndromes.
20. Which antiplatelet agent is commonly used for secondary prevention in coronary artery
disease?
A. Clopidogrel
B. Warfarin
