Diagnosis (Chamberlain) Complete A+ Guide with
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Section 1: Cardiovascular System (Questions 1-40)
1. A 62-year-old male presents to the emergency department with substernal
chest pressure that began 90 minutes ago while shoveling snow. The pain radiates
to his left arm and jaw, and he reports diaphoresis and nausea. His blood pressure
is 155/95 mmHg, heart rate 110 bpm. What is the most appropriate initial
diagnostic test?
A. Chest X-ray
B. 12-lead ECG
C. Cardiac troponin
D. Stress echocardiogram
Correct Answer: B
Rationale: For any patient presenting with symptoms suggestive of acute
coronary syndrome (ACS), a 12-lead ECG should be obtained within 10 minutes of
arrival. The ECG can identify ST-elevation myocardial infarction (STEMI) requiring
immediate reperfusion therapy. While troponin is important for diagnosis, the
ECG provides immediate actionable information for time-sensitive interventions.
2. The ECG shows ST-segment elevation in leads V1-V4. Which coronary artery is
most likely occluded?
A. Right coronary artery
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,B. Left circumflex artery
C. Left anterior descending artery
D. Posterior descending artery
Correct Answer: C
Rationale: ST-segment elevation in the anterior precordial leads (V1-V4) indicates
an anterior wall myocardial infarction, which is typically caused by occlusion of
the left anterior descending artery (LAD). The LAD supplies the anterior wall of
the left ventricle and the interventricular septum.
3. A 55-year-old woman with a history of hypertension presents with intermittent
chest tightness that occurs when she walks briskly and resolves with rest. Her ECG
is normal at rest. Which diagnostic test is most appropriate next?
A. Coronary angiography
B. Exercise stress test
C. Echocardiogram
D. Serum troponin
Correct Answer: B
Rationale: The patient has stable angina symptoms. An exercise stress test is
indicated to evaluate for inducible ischemia. It is safe and noninvasive. Coronary
angiography is reserved for patients with high-risk features or positive stress test.
4. A 70-year-old man presents with syncope while mowing the lawn. He has a
history of heart failure with reduced ejection fraction (EF 30%). On exam, heart
rate is 140 bpm, irregularly irregular, with variable S1 intensity. What is the most
likely diagnosis?
A. Atrial flutter
B. Atrial fibrillation
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,C. Multifocal atrial tachycardia
D. Ventricular tachycardia
Correct Answer: B
Rationale: Atrial fibrillation is characterized by irregularly irregular rhythm with no
discernible P waves. It is common in patients with heart failure. Atrial flutter
typically has regular rhythm with sawtooth waves. Ventricular tachycardia is
usually regular and wide-complex.
5. A 45-year-old obese male with a history of obstructive sleep apnea reports
sudden onset of sharp, stabbing chest pain that worsens with deep inspiration. He
is afebrile, heart rate 105 bpm, respiratory rate 24, oxygen saturation 96% on
room air. Which diagnosis is most likely?
A. Unstable angina
B. Pericarditis
C. Pulmonary embolism
D. Pneumothorax
Correct Answer: B
Rationale: Pleuritic chest pain (worsening with inspiration) is classic for
pericarditis, especially when positional. The patient is not hypoxic, which makes
pulmonary embolism less likely. Pericarditis often follows viral illness and may
have a pericardial friction rub.
6. A 68-year-old woman with hypertension and diabetes reports dizziness when
standing up from a seated position. Her supine blood pressure is 150/90 mmHg,
and standing blood pressure is 110/70 mmHg with lightheadedness. What is the
most likely cause?
A. Dehydration
B. Medication-induced orthostatic hypotension (e.g., antihypertensives)
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, C. Autonomic neuropathy from diabetes
D. Cardiac arrhythmia
Correct Answer: B
Rationale: Orthostatic hypotension (drop in systolic BP ≥20 mmHg or diastolic ≥10
mmHg within 3 minutes of standing) is common with antihypertensive
medications. Diabetic autonomic neuropathy is also possible, but medication
effect is more common and should be assessed first.
7. A 50-year-old male presents with acute-onset, tearing chest pain that radiates
to his back. His blood pressure is 160/100 mmHg in the right arm and 100/60
mmHg in the left arm. What is the most likely diagnosis?
A. Acute myocardial infarction
B. Aortic dissection
C. Pulmonary embolism
D. Esophageal rupture
Correct Answer: B
Rationale: Aortic dissection presents with sudden, severe, tearing chest or back
pain and may cause differential blood pressures between arms. This is a surgical
emergency requiring immediate imaging (CT angiography).
8. A 72-year-old male with a history of smoking and COPD reports progressive
shortness of breath and bilateral lower extremity edema. On exam, jugular
venous pressure is elevated, and he has a right ventricular heave. What is the
most likely diagnosis?
A. Left-sided heart failure
B. Cor pulmonale (right heart failure from pulmonary disease)
C. Pericardial effusion
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