NBME CBSE ACTUAL TEST – 350 UNIQUE
QUESTIONS WITH DETAILED VERIFIED
ANSWERS (100% CORRECT ANSWERS WITH
RATIONALES /ALREADY GRADED A+
SECTION 1: CARDIOLOGY (Questions 1–35)
Question 1
A 65-year-old man with a history of hypertension presents with chest pain that
occurs during exertion and is relieved by rest. An ECG shows ST-segment
depression during treadmill testing. Which of the following is the most likely
underlying mechanism?
A) Fixed atherosclerotic plaque causing critical stenosis
B) Rupture of an atherosclerotic plaque with thrombus formation
C) Transient platelet aggregation without plaque rupture
D) Coronary artery vasospasm
E) Myocardial bridging
Answer: A) Fixed atherosclerotic plaque causing critical stenosis
Rationale: This patient has stable angina, characterized by chest pain with exertion
that resolves with rest. The underlying mechanism is a fixed atherosclerotic plaque
causing critical coronary artery stenosis (typically >70% luminal narrowing).
During exertion, increased myocardial oxygen demand cannot be met due to the
fixed obstruction, leading to ischemia. Plaque rupture with thrombus formation (B)
causes unstable angina or myocardial infarction. Vasospasm (D) causes
1
,Prinzmetal/variant angina, which occurs at rest. Myocardial bridging (E) is a
congenital condition where a coronary artery runs through the myocardium.
---
Question 2
A 55-year-old woman with acute inferior wall ST-elevation myocardial infarction
develops hypotension, bradycardia, and jugular venous distention. Which of the
following is the most likely cause?
A) Papillary muscle rupture
B) Right ventricular infarction
C) Ventricular septal rupture
D) Cardiac tamponade
E) Left ventricular free wall rupture
Answer: B) Right ventricular infarction
Rationale: Inferior wall MI often involves the right ventricle due to the shared
blood supply from the right coronary artery. Right ventricular infarction presents
with hypotension, bradycardia (due to Bezold-Jarisch reflex), elevated JVP, and
clear lungs (Kussmaul's sign may be present). Treatment requires volume loading
and avoiding nitrates. Papillary muscle rupture (A) causes acute mitral
regurgitation with pulmonary edema. Ventricular septal rupture (C) causes a new
holosystolic murmur and acute heart failure. Cardiac tamponade (D) presents with
pulsus paradoxus and muffled heart sounds.
---
2
,Question 3
A 72-year-old man with a systolic ejection murmur heard best at the right upper
sternal border that radiates to the carotids has a diminished S2 heart sound. Which
of the following hemodynamic findings is most likely?
A) Increased left ventricular end-diastolic pressure
B) Decreased left ventricular ejection time
C) Increased left ventricular pressure gradient during systole
D) Decreased left ventricular afterload
E) Normal left ventricular pressure
Answer: C) Increased left ventricular pressure gradient during systole
Rationale: This patient has aortic stenosis, characterized by a systolic ejection
murmur at the right upper sternal border that radiates to the carotids, with a
diminished or absent S2. In aortic stenosis, there is a pressure gradient between the
left ventricle and aorta during systole due to the obstructed outflow tract. Left
ventricular pressure is increased while aortic pressure is normal or decreased,
creating the gradient. Left ventricular end-diastolic pressure (A) increases in later
stages but is not the primary hemodynamic finding. Ejection time (B) is prolonged,
not decreased. Afterload (D) is increased, not decreased.
---
Question 4
A 45-year-old woman presents with progressive dyspnea on exertion and a mid-
diastolic rumbling murmur with an opening snap. Echocardiography shows a
"hockey stick" appearance of the mitral valve leaflets. Which of the following is
the most common cause of this condition?
3
, A) Congenital mitral stenosis
B) Rheumatic heart disease
C) Infective endocarditis
D) Mitral annular calcification
E) Carcinoid syndrome
Answer: B) Rheumatic heart disease
Rationale: This patient has mitral stenosis, characterized by a mid-diastolic
rumbling murmur, opening snap, and "hockey stick" appearance of the anterior
mitral valve leaflet on echocardiography. The most common cause worldwide is
rheumatic heart disease, which results from prior group A streptococcal pharyngitis
causing an autoimmune reaction. Rheumatic fever leads to thickening, fusion, and
calcification of the mitral valve commissures and leaflets. Congenital mitral
stenosis (A) is rare. Mitral annular calcification (D) causes a different murmur
pattern and is seen in elderly patients.
---
Question 5
A 60-year-old man with a history of myocardial infarction presents with worsening
dyspnea. On auscultation, there is a holosystolic murmur at the apex that radiates
to the axilla. Which of the following is the most likely diagnosis?
A) Aortic stenosis
B) Mitral regurgitation
C) Ventricular septal defect
4
QUESTIONS WITH DETAILED VERIFIED
ANSWERS (100% CORRECT ANSWERS WITH
RATIONALES /ALREADY GRADED A+
SECTION 1: CARDIOLOGY (Questions 1–35)
Question 1
A 65-year-old man with a history of hypertension presents with chest pain that
occurs during exertion and is relieved by rest. An ECG shows ST-segment
depression during treadmill testing. Which of the following is the most likely
underlying mechanism?
A) Fixed atherosclerotic plaque causing critical stenosis
B) Rupture of an atherosclerotic plaque with thrombus formation
C) Transient platelet aggregation without plaque rupture
D) Coronary artery vasospasm
E) Myocardial bridging
Answer: A) Fixed atherosclerotic plaque causing critical stenosis
Rationale: This patient has stable angina, characterized by chest pain with exertion
that resolves with rest. The underlying mechanism is a fixed atherosclerotic plaque
causing critical coronary artery stenosis (typically >70% luminal narrowing).
During exertion, increased myocardial oxygen demand cannot be met due to the
fixed obstruction, leading to ischemia. Plaque rupture with thrombus formation (B)
causes unstable angina or myocardial infarction. Vasospasm (D) causes
1
,Prinzmetal/variant angina, which occurs at rest. Myocardial bridging (E) is a
congenital condition where a coronary artery runs through the myocardium.
---
Question 2
A 55-year-old woman with acute inferior wall ST-elevation myocardial infarction
develops hypotension, bradycardia, and jugular venous distention. Which of the
following is the most likely cause?
A) Papillary muscle rupture
B) Right ventricular infarction
C) Ventricular septal rupture
D) Cardiac tamponade
E) Left ventricular free wall rupture
Answer: B) Right ventricular infarction
Rationale: Inferior wall MI often involves the right ventricle due to the shared
blood supply from the right coronary artery. Right ventricular infarction presents
with hypotension, bradycardia (due to Bezold-Jarisch reflex), elevated JVP, and
clear lungs (Kussmaul's sign may be present). Treatment requires volume loading
and avoiding nitrates. Papillary muscle rupture (A) causes acute mitral
regurgitation with pulmonary edema. Ventricular septal rupture (C) causes a new
holosystolic murmur and acute heart failure. Cardiac tamponade (D) presents with
pulsus paradoxus and muffled heart sounds.
---
2
,Question 3
A 72-year-old man with a systolic ejection murmur heard best at the right upper
sternal border that radiates to the carotids has a diminished S2 heart sound. Which
of the following hemodynamic findings is most likely?
A) Increased left ventricular end-diastolic pressure
B) Decreased left ventricular ejection time
C) Increased left ventricular pressure gradient during systole
D) Decreased left ventricular afterload
E) Normal left ventricular pressure
Answer: C) Increased left ventricular pressure gradient during systole
Rationale: This patient has aortic stenosis, characterized by a systolic ejection
murmur at the right upper sternal border that radiates to the carotids, with a
diminished or absent S2. In aortic stenosis, there is a pressure gradient between the
left ventricle and aorta during systole due to the obstructed outflow tract. Left
ventricular pressure is increased while aortic pressure is normal or decreased,
creating the gradient. Left ventricular end-diastolic pressure (A) increases in later
stages but is not the primary hemodynamic finding. Ejection time (B) is prolonged,
not decreased. Afterload (D) is increased, not decreased.
---
Question 4
A 45-year-old woman presents with progressive dyspnea on exertion and a mid-
diastolic rumbling murmur with an opening snap. Echocardiography shows a
"hockey stick" appearance of the mitral valve leaflets. Which of the following is
the most common cause of this condition?
3
, A) Congenital mitral stenosis
B) Rheumatic heart disease
C) Infective endocarditis
D) Mitral annular calcification
E) Carcinoid syndrome
Answer: B) Rheumatic heart disease
Rationale: This patient has mitral stenosis, characterized by a mid-diastolic
rumbling murmur, opening snap, and "hockey stick" appearance of the anterior
mitral valve leaflet on echocardiography. The most common cause worldwide is
rheumatic heart disease, which results from prior group A streptococcal pharyngitis
causing an autoimmune reaction. Rheumatic fever leads to thickening, fusion, and
calcification of the mitral valve commissures and leaflets. Congenital mitral
stenosis (A) is rare. Mitral annular calcification (D) causes a different murmur
pattern and is seen in elderly patients.
---
Question 5
A 60-year-old man with a history of myocardial infarction presents with worsening
dyspnea. On auscultation, there is a holosystolic murmur at the apex that radiates
to the axilla. Which of the following is the most likely diagnosis?
A) Aortic stenosis
B) Mitral regurgitation
C) Ventricular septal defect
4
