COMSAE Phase 2 Form 116 Practice
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download
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Question 1
A 67-year-old man presents with crushing substernal chest pain radiating to his left
arm for 45 minutes. ECG shows ST-segment elevations in leads II, III, and aVF.
Which coronary artery is most likely occluded?
A) Left anterior descending artery
B) Left circumflex artery
C) Right coronary artery
D) Posterior descending artery
Rationale & Explanation:
ST-segment elevations in leads II, III, and aVF indicate an inferior wall
myocardial infarction . The inferior wall of the left ventricle is supplied by
the right coronary artery (RCA) in approximately 80% of individuals (right-
dominant circulation). The remaining 20% have left-dominant circulation where
the left circumflex supplies the inferior wall.
Clinical correlates of RCA occlusion:
, • Often presents with bradycardia (sinus bradycardia or AV block) due to
increased vagal tone or ischemia to the AV node (supplied by RCA in 90%
of people)
• May involve the right ventricle (obtain right-sided ECG leads V3R-V4R)
• Complications include hypotension, heart block, and mitral regurgitation (if
papillary muscle involved)
Key distinctions:
• LAD occlusion → anterior wall MI (V1-V4)
• LCx occlusion → lateral wall MI (I, aVL, V5-V6)
• Posterior wall MI (tall R waves in V1-V2, ST depression in anterior leads)
Question 2
A 72-year-old woman with atrial fibrillation presents with sudden onset of severe
pain in her right leg. The right leg is pale, cold, and pulseless with paresthesias and
paralysis. What is the most likely diagnosis?
A) Deep vein thrombosis
B) Acute arterial embolism
C) Cellulitis
D) Sciatica
Rationale & Explanation:
This patient presents with the five P's of acute limb ischemia: Pain, Pallor,
Pulselessness, Paresthesia, and Paralysis . In a patient with atrial fibrillation, the
most common source is a cardioembolic event (thrombus from the left atrium or
left atrial appendage embolizing to the femoral or popliteal artery).
Key features:
, • Atrial fibrillation is the most common cause of arterial embolism
• Emboli tend to lodge at arterial bifurcations (femoral, popliteal, brachial)
• This is a surgical emergency requiring emergent embolectomy or
thrombolysis to prevent limb loss
Differential diagnosis:
• DVT presents with swelling, warmth, and pain but not pallor or
pulselessness
• Cellulitis presents with erythema, warmth, and tenderness
• Sciatica presents with radiating pain but not vascular compromise
Question 3
A 4-year-old boy is brought to the clinic for a routine checkup. On cardiac
auscultation, a harsh, holosystolic murmur is best appreciated at the lower left
sternal border. The child is active, meets all developmental milestones, and shows
no signs of cyanosis or digital clubbing. Which of the following is the most likely
diagnosis?
A) Patent ductus arteriosus
B) Ventricular septal defect
C) Tetralogy of Fallot
D) Atrial septal defect
Rationale & Explanation:
A harsh, holosystolic murmur heard best at the lower left sternal border is the
classic presentation of a ventricular septal defect (VSD) . Small defects are often
asymptomatic aside from the loud murmur.
Key characteristics of VSD:
, • Most common congenital heart defect (25-30% of all CHD)
• Holosystolic murmur (blood shunts from left to right throughout systole)
• Best heard at left lower sternal border
• Small VSDs may close spontaneously (especially muscular type)
• Large VSDs present with heart failure, failure to thrive, and recurrent
infections
Differential diagnosis by murmur location:
Defect Murmur Location
VSD Harsh, holosystolic Lower left sternal border
PDA Continuous "machinery" Left infraclavicular area
ASD Systolic ejection murmur Left upper sternal border (fixed split S2
Tetralogy of Fallot Systolic ejection murmur Left sternal border (cyanotic spells)
Question 4
A 55-year-old man with a 15-year history of type 2 diabetes mellitus presents with
a gradual onset of numbness and a "pins and needles" sensation in both feet.
Physical examination demonstrates decreased sensation to light touch, pinprick,
and vibration in a symmetrical distribution up to the mid-calf. Monofilament
testing is abnormal. Which of the following is the most likely diagnosis?
A) Charcot arthropathy
B) Distal symmetric polyneuropathy
C) Guillain-Barré syndrome
D) Myasthenia gravis
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download
Question 1
A 67-year-old man presents with crushing substernal chest pain radiating to his left
arm for 45 minutes. ECG shows ST-segment elevations in leads II, III, and aVF.
Which coronary artery is most likely occluded?
A) Left anterior descending artery
B) Left circumflex artery
C) Right coronary artery
D) Posterior descending artery
Rationale & Explanation:
ST-segment elevations in leads II, III, and aVF indicate an inferior wall
myocardial infarction . The inferior wall of the left ventricle is supplied by
the right coronary artery (RCA) in approximately 80% of individuals (right-
dominant circulation). The remaining 20% have left-dominant circulation where
the left circumflex supplies the inferior wall.
Clinical correlates of RCA occlusion:
, • Often presents with bradycardia (sinus bradycardia or AV block) due to
increased vagal tone or ischemia to the AV node (supplied by RCA in 90%
of people)
• May involve the right ventricle (obtain right-sided ECG leads V3R-V4R)
• Complications include hypotension, heart block, and mitral regurgitation (if
papillary muscle involved)
Key distinctions:
• LAD occlusion → anterior wall MI (V1-V4)
• LCx occlusion → lateral wall MI (I, aVL, V5-V6)
• Posterior wall MI (tall R waves in V1-V2, ST depression in anterior leads)
Question 2
A 72-year-old woman with atrial fibrillation presents with sudden onset of severe
pain in her right leg. The right leg is pale, cold, and pulseless with paresthesias and
paralysis. What is the most likely diagnosis?
A) Deep vein thrombosis
B) Acute arterial embolism
C) Cellulitis
D) Sciatica
Rationale & Explanation:
This patient presents with the five P's of acute limb ischemia: Pain, Pallor,
Pulselessness, Paresthesia, and Paralysis . In a patient with atrial fibrillation, the
most common source is a cardioembolic event (thrombus from the left atrium or
left atrial appendage embolizing to the femoral or popliteal artery).
Key features:
, • Atrial fibrillation is the most common cause of arterial embolism
• Emboli tend to lodge at arterial bifurcations (femoral, popliteal, brachial)
• This is a surgical emergency requiring emergent embolectomy or
thrombolysis to prevent limb loss
Differential diagnosis:
• DVT presents with swelling, warmth, and pain but not pallor or
pulselessness
• Cellulitis presents with erythema, warmth, and tenderness
• Sciatica presents with radiating pain but not vascular compromise
Question 3
A 4-year-old boy is brought to the clinic for a routine checkup. On cardiac
auscultation, a harsh, holosystolic murmur is best appreciated at the lower left
sternal border. The child is active, meets all developmental milestones, and shows
no signs of cyanosis or digital clubbing. Which of the following is the most likely
diagnosis?
A) Patent ductus arteriosus
B) Ventricular septal defect
C) Tetralogy of Fallot
D) Atrial septal defect
Rationale & Explanation:
A harsh, holosystolic murmur heard best at the lower left sternal border is the
classic presentation of a ventricular septal defect (VSD) . Small defects are often
asymptomatic aside from the loud murmur.
Key characteristics of VSD:
, • Most common congenital heart defect (25-30% of all CHD)
• Holosystolic murmur (blood shunts from left to right throughout systole)
• Best heard at left lower sternal border
• Small VSDs may close spontaneously (especially muscular type)
• Large VSDs present with heart failure, failure to thrive, and recurrent
infections
Differential diagnosis by murmur location:
Defect Murmur Location
VSD Harsh, holosystolic Lower left sternal border
PDA Continuous "machinery" Left infraclavicular area
ASD Systolic ejection murmur Left upper sternal border (fixed split S2
Tetralogy of Fallot Systolic ejection murmur Left sternal border (cyanotic spells)
Question 4
A 55-year-old man with a 15-year history of type 2 diabetes mellitus presents with
a gradual onset of numbness and a "pins and needles" sensation in both feet.
Physical examination demonstrates decreased sensation to light touch, pinprick,
and vibration in a symmetrical distribution up to the mid-calf. Monofilament
testing is abnormal. Which of the following is the most likely diagnosis?
A) Charcot arthropathy
B) Distal symmetric polyneuropathy
C) Guillain-Barré syndrome
D) Myasthenia gravis
