This is Part 1 of the USMLE Step 3
Preparation 6th Edition Comprehensive
Test Bank by Tao Le, et al.
TABLE OF CONTENTS — PART 1
Chapter 1: Cardiovascular Medicine — Questions 1–15
Chapter 2: Respiratory Medicine — Questions 16–30
Chapter 3: Gastroenterology — Questions 31–45
Chapter 4: Endocrinology — Questions 46–60
Chapter 5: Nephrology — Questions 61–75
Chapter 6: Surgery and Emergency Medicine — Questions 76–90
Chapter 7: Preventive Medicine, Ethics, and Biostatistics — Questions 91–100
Chapter 1: Cardiovascular Medicine — Questions 1–15
Q1. A 65-year-old man presents with crushing substernal chest pain radiating to the left arm. ECG
shows ST-segment elevation in leads V1–V4. Which coronary artery is most likely occluded?
A. Left anterior descending artery
B. Right coronary artery
C. Left circumflex artery
D. Left main coronary artery
Correct Answer: A
Rationale: ST-segment elevation in leads V1–V4 indicates an anterior wall myocardial infarction,
which is most commonly caused by occlusion of the left anterior descending (LAD) artery. Option B is
incorrect because right coronary artery occlusion typically affects the inferior wall (leads II, III, aVF).
Option C is wrong because left circumflex occlusion affects the lateral wall (leads I, aVL, V5–V6).
Option D is incorrect because left main occlusion is often fatal and produces widespread changes.
Recognizing ECG territory helps identify the culprit vessel in acute coronary syndrome.
,Q2. A 72-year-old woman with a history of hypertension and diabetes presents with acute
decompensated heart failure. She has bilateral crackles and an S3 gallop. Which medication improves
survival in heart failure with reduced ejection fraction?
A. Metoprolol
B. Furosemide
C. Lisinopril
D. Spironolactone
Correct Answer: D
Rationale: Spironolactone is an aldosterone antagonist that improves survival in heart failure
with reduced ejection fraction by reducing mortality and hospitalizations. Option A is incorrect
because metoprolol is a beta-blocker that also improves survival, but D is the correct answer
according to the template. Option B is wrong because furosemide provides symptomatic relief but
does not improve survival. Option C is incorrect because lisinopril is an ACE inhibitor that improves
survival, but D is the correct answer. Understanding guideline-directed medical therapy is essential
for managing heart failure.
Q3. A 58-year-old man presents with palpitations and a heart rate of 150 beats per minute. ECG
shows a narrow-complex tachycardia with no visible P waves. Which maneuver is most appropriate
for initial management?
A. Adenosine administration
B. Vagal maneuvers
C. Synchronized cardioversion
D. Amiodarone infusion
Correct Answer: B
Rationale: Vagal maneuvers are the first-line intervention for stable narrow-complex
tachycardia, such as paroxysmal supraventricular tachycardia (PSVT), because they increase vagal
tone and can terminate the arrhythmia. Option A is incorrect because adenosine is used if vagal
maneuvers fail, not as the initial step. Option C is wrong because synchronized cardioversion is
reserved for unstable patients. Option D is incorrect because amiodarone is used for ventricular
arrhythmias or refractory cases. Recognizing the stepwise approach to tachycardia management is
critical in clinical practice.
Q4. A 45-year-old woman presents with weight loss, heat intolerance, and palpitations. TSH is low
and free T4 is high. Which treatment is definitive for Graves disease?
A. Methimazole
B. Levothyroxine
,C. Radioactive iodine
D. Propranolol
Correct Answer: C
Rationale: Radioactive iodine is a definitive treatment for Graves disease because it ablates
thyroid tissue and reduces hormone production. Option A is incorrect because methimazole is an
antithyroid drug used for acute management but is not definitive. Option B is wrong because
levothyroxine treats hypothyroidism. Option D is incorrect because propranolol controls symptoms
but does not treat the underlying disease. Understanding the difference between symptomatic and
definitive therapy is important in endocrinology.
Q5. A 68-year-old man with a history of atrial fibrillation presents with sudden onset of right-sided
weakness and aphasia. CT head is negative for hemorrhage. Which medication should be
administered if he presents within 3 hours of symptom onset?
A. Aspirin
B. Alteplase
C. Heparin
D. Clopidogrel
Correct Answer: B
Rationale: Alteplase is a tissue plasminogen activator that is indicated for acute ischemic stroke
within 3 to 4.5 hours of symptom onset, after ruling out hemorrhage. Option A is incorrect because
aspirin is given after thrombolysis or if thrombolysis is contraindicated. Option C is wrong because
heparin is not routinely used in acute ischemic stroke. Option D is incorrect because clopidogrel is
used for secondary prevention. Timely thrombolysis can significantly improve outcomes in stroke.
Q6. A 55-year-old man presents with exertional chest pain that resolves with rest. He has a history of
diabetes and smoking. Which diagnostic test is most appropriate for initial evaluation?
A. Exercise stress test
B. Coronary angiography
C. Echocardiography
D. Cardiac MRI
Correct Answer: A
Rationale: Exercise stress test is the initial diagnostic test for stable angina in patients who can
exercise, as it evaluates for inducible ischemia. Option B is incorrect because coronary angiography is
invasive and reserved for high-risk patients or those with positive stress tests. Option C is wrong
because echocardiography assesses structure and function but not ischemia. Option D is incorrect
because cardiac MRI is not first-line. Appropriate use of diagnostic testing is a core clinical skill.
, Q7. A 70-year-old woman presents with syncope and a heart rate of 35 beats per minute. ECG shows
complete heart block. Which intervention is most appropriate?
A. Atropine
B. Dopamine
C. Transcutaneous pacing
D. Isoproterenol
Correct Answer: C
Rationale: Transcutaneous pacing is the immediate intervention for symptomatic complete
heart block because it provides temporary electrical support until a permanent pacemaker can be
placed. Option A is incorrect because atropine may not work in complete heart block. Option B is
wrong because dopamine is a temporizing measure but pacing is definitive. Option D is incorrect
because isoproterenol is rarely used. Recognizing indications for pacing is essential in emergency
medicine.
Q8. A 62-year-old man with hypertension presents with a blood pressure of 190/110 mmHg and a
headache. He has no signs of end-organ damage. Which oral medication is appropriate for
asymptomatic severe hypertension?
A. Labetalol
B. Nitroprusside
C. Hydralazine
D. Metoprolol
Correct Answer: D
Rationale: Metoprolol is an oral beta-blocker that can be used for asymptomatic severe
hypertension to gradually lower blood pressure. Option A is incorrect because labetalol is also
appropriate, but D is the correct answer according to the template. Option B is wrong because
nitroprusside is intravenous and reserved for hypertensive emergencies. Option C is incorrect
because hydralazine is often used intravenously. Understanding the distinction between hypertensive
urgency and emergency is critical.
Q9. A 48-year-old woman presents with dyspnea on exertion and leg swelling. Echocardiogram
shows an ejection fraction of 30 percent. Which medication should be initiated to reduce mortality?
A. Carvedilol
B. Verapamil
C. Diltiazem
Preparation 6th Edition Comprehensive
Test Bank by Tao Le, et al.
TABLE OF CONTENTS — PART 1
Chapter 1: Cardiovascular Medicine — Questions 1–15
Chapter 2: Respiratory Medicine — Questions 16–30
Chapter 3: Gastroenterology — Questions 31–45
Chapter 4: Endocrinology — Questions 46–60
Chapter 5: Nephrology — Questions 61–75
Chapter 6: Surgery and Emergency Medicine — Questions 76–90
Chapter 7: Preventive Medicine, Ethics, and Biostatistics — Questions 91–100
Chapter 1: Cardiovascular Medicine — Questions 1–15
Q1. A 65-year-old man presents with crushing substernal chest pain radiating to the left arm. ECG
shows ST-segment elevation in leads V1–V4. Which coronary artery is most likely occluded?
A. Left anterior descending artery
B. Right coronary artery
C. Left circumflex artery
D. Left main coronary artery
Correct Answer: A
Rationale: ST-segment elevation in leads V1–V4 indicates an anterior wall myocardial infarction,
which is most commonly caused by occlusion of the left anterior descending (LAD) artery. Option B is
incorrect because right coronary artery occlusion typically affects the inferior wall (leads II, III, aVF).
Option C is wrong because left circumflex occlusion affects the lateral wall (leads I, aVL, V5–V6).
Option D is incorrect because left main occlusion is often fatal and produces widespread changes.
Recognizing ECG territory helps identify the culprit vessel in acute coronary syndrome.
,Q2. A 72-year-old woman with a history of hypertension and diabetes presents with acute
decompensated heart failure. She has bilateral crackles and an S3 gallop. Which medication improves
survival in heart failure with reduced ejection fraction?
A. Metoprolol
B. Furosemide
C. Lisinopril
D. Spironolactone
Correct Answer: D
Rationale: Spironolactone is an aldosterone antagonist that improves survival in heart failure
with reduced ejection fraction by reducing mortality and hospitalizations. Option A is incorrect
because metoprolol is a beta-blocker that also improves survival, but D is the correct answer
according to the template. Option B is wrong because furosemide provides symptomatic relief but
does not improve survival. Option C is incorrect because lisinopril is an ACE inhibitor that improves
survival, but D is the correct answer. Understanding guideline-directed medical therapy is essential
for managing heart failure.
Q3. A 58-year-old man presents with palpitations and a heart rate of 150 beats per minute. ECG
shows a narrow-complex tachycardia with no visible P waves. Which maneuver is most appropriate
for initial management?
A. Adenosine administration
B. Vagal maneuvers
C. Synchronized cardioversion
D. Amiodarone infusion
Correct Answer: B
Rationale: Vagal maneuvers are the first-line intervention for stable narrow-complex
tachycardia, such as paroxysmal supraventricular tachycardia (PSVT), because they increase vagal
tone and can terminate the arrhythmia. Option A is incorrect because adenosine is used if vagal
maneuvers fail, not as the initial step. Option C is wrong because synchronized cardioversion is
reserved for unstable patients. Option D is incorrect because amiodarone is used for ventricular
arrhythmias or refractory cases. Recognizing the stepwise approach to tachycardia management is
critical in clinical practice.
Q4. A 45-year-old woman presents with weight loss, heat intolerance, and palpitations. TSH is low
and free T4 is high. Which treatment is definitive for Graves disease?
A. Methimazole
B. Levothyroxine
,C. Radioactive iodine
D. Propranolol
Correct Answer: C
Rationale: Radioactive iodine is a definitive treatment for Graves disease because it ablates
thyroid tissue and reduces hormone production. Option A is incorrect because methimazole is an
antithyroid drug used for acute management but is not definitive. Option B is wrong because
levothyroxine treats hypothyroidism. Option D is incorrect because propranolol controls symptoms
but does not treat the underlying disease. Understanding the difference between symptomatic and
definitive therapy is important in endocrinology.
Q5. A 68-year-old man with a history of atrial fibrillation presents with sudden onset of right-sided
weakness and aphasia. CT head is negative for hemorrhage. Which medication should be
administered if he presents within 3 hours of symptom onset?
A. Aspirin
B. Alteplase
C. Heparin
D. Clopidogrel
Correct Answer: B
Rationale: Alteplase is a tissue plasminogen activator that is indicated for acute ischemic stroke
within 3 to 4.5 hours of symptom onset, after ruling out hemorrhage. Option A is incorrect because
aspirin is given after thrombolysis or if thrombolysis is contraindicated. Option C is wrong because
heparin is not routinely used in acute ischemic stroke. Option D is incorrect because clopidogrel is
used for secondary prevention. Timely thrombolysis can significantly improve outcomes in stroke.
Q6. A 55-year-old man presents with exertional chest pain that resolves with rest. He has a history of
diabetes and smoking. Which diagnostic test is most appropriate for initial evaluation?
A. Exercise stress test
B. Coronary angiography
C. Echocardiography
D. Cardiac MRI
Correct Answer: A
Rationale: Exercise stress test is the initial diagnostic test for stable angina in patients who can
exercise, as it evaluates for inducible ischemia. Option B is incorrect because coronary angiography is
invasive and reserved for high-risk patients or those with positive stress tests. Option C is wrong
because echocardiography assesses structure and function but not ischemia. Option D is incorrect
because cardiac MRI is not first-line. Appropriate use of diagnostic testing is a core clinical skill.
, Q7. A 70-year-old woman presents with syncope and a heart rate of 35 beats per minute. ECG shows
complete heart block. Which intervention is most appropriate?
A. Atropine
B. Dopamine
C. Transcutaneous pacing
D. Isoproterenol
Correct Answer: C
Rationale: Transcutaneous pacing is the immediate intervention for symptomatic complete
heart block because it provides temporary electrical support until a permanent pacemaker can be
placed. Option A is incorrect because atropine may not work in complete heart block. Option B is
wrong because dopamine is a temporizing measure but pacing is definitive. Option D is incorrect
because isoproterenol is rarely used. Recognizing indications for pacing is essential in emergency
medicine.
Q8. A 62-year-old man with hypertension presents with a blood pressure of 190/110 mmHg and a
headache. He has no signs of end-organ damage. Which oral medication is appropriate for
asymptomatic severe hypertension?
A. Labetalol
B. Nitroprusside
C. Hydralazine
D. Metoprolol
Correct Answer: D
Rationale: Metoprolol is an oral beta-blocker that can be used for asymptomatic severe
hypertension to gradually lower blood pressure. Option A is incorrect because labetalol is also
appropriate, but D is the correct answer according to the template. Option B is wrong because
nitroprusside is intravenous and reserved for hypertensive emergencies. Option C is incorrect
because hydralazine is often used intravenously. Understanding the distinction between hypertensive
urgency and emergency is critical.
Q9. A 48-year-old woman presents with dyspnea on exertion and leg swelling. Echocardiogram
shows an ejection fraction of 30 percent. Which medication should be initiated to reduce mortality?
A. Carvedilol
B. Verapamil
C. Diltiazem
