A 47-year-old woman comes to the physician because of a 1-month history of progressive weakness. She has had increased difficulty climbing stairs and standing from a seated position. She takes no medications. Neurologic examination shows weakness of the proximal muscles. Skin examination shows diffuse erythema of the upper back, posterior neck, and shoulders. A photograph of the patient's eye is shown. Antibodies against which of the following are most likely to be present in this patient?
Q1112
A 12-year-old boy is brought by his mother to the emergency room because of a swollen, hot, and tender knee that he sustained after falling on his way home. He has never had a swollen joint before; however, he has had frequent nosebleeds throughout his life. His mother is worried because they live with her parents who are currently on blood thinners. Every morning she puts the blood thinner pill in the boy's grandfather's milk and was concerned that she may have switched it this morning. Family history reveals a number of uncles who have had bleeding disorders; however, the mother does not know the exact disorder suffered by these relatives. A hematologic panel reveals the following findings:
Bleeding time: Increased
Prothrombin time: 12 seconds
Partial thromboplastin time (PTT): 55 seconds
PTT after factor mixing study: 37 seconds
Which of the following most likely explains the abnormal partial thromboplastin time in this patient?
Q1113
A 42-year-old man comes to the physician for a health maintenance examination. He has had generalized fatigue and muscle aches since his previous visit 6 months ago. He has hypertension and gastroesophageal reflux disease. Current medications include amlodipine and omeprazole. His temperature is 37.1°C (98.1°F), pulse is 88/min and blood pressure is 156/102 mm Hg. Physical examination shows no abnormalities. Serum studies show:
Na+ 143 mEq/L
K+ 2.3 mEq/L
Cl- 100 mEq/L
HCO3- 31 mEq/L
Urea nitrogen 14 mg/dL
Creatinine 1 mg/dL
His blood pressure medication is discontinued. One week later his plasma aldosterone concentration is 35 ng/dL (N=3.6 - 24.0 ng/dL) and plasma renin activity is 0.4 ng/mL/h (N=0.3 to 4.2 ng/mL/h). An oral sodium loading test over 3 days fails to reduce aldosterone. A contrast-enhanced CT scan of the abdomen and pelvis shows a 3-cm, homogenous, right-sided adrenal mass with rapid contrast washout. He is counseled about his treatment options and chooses to pursue surgery. Which of the following is the most appropriate next step in management?
Q1114
A 68-year-old female presents to the emergency room with acute onset of dyspnea and hemoptysis. Her past medical history is unremarkable and she has had no prior surgeries. A ventilation-perfusion scan demonstrates a large perfusion defect that is not matched by a ventilation defect in the left lower lobe. Which of the following would you also expect to find in this patient:
Q1115
A 45-year-old African American woman presents to her family physician for a routine examination. Past medical history is positive for amyloidosis and non-rhythm-based cardiac abnormalities secondary to the amyloidosis. Which of the following cardiac parameters would be expected in this patient?
Q1116
A 34-year-old man comes to the physician for a routine health maintenance examination. He was diagnosed with HIV 8 years ago. He is currently receiving triple antiretroviral therapy. He is sexually active and uses condoms consistently. He is planning a trip to Thailand with his partner to celebrate his 35th birthday in 6 weeks. His last tetanus and diphtheria booster was given 4 years ago. He received three vaccinations against hepatitis B 5 years ago. He had chickenpox as a child. Other immunization records are unknown. Vital signs are within normal limits. Cardiopulmonary examination shows no abnormalities. Leukocyte count shows 8,700/mm3, and CD4+ T-lymphocyte count is 480 cells/mm3 (Normal ≥ 500); anti-HBs is 150 mIU/mL. Which of the following recommendations is most appropriate at this time?
Q1117
Two days after admission to the hospital, a 74-year-old man develops confusion and headache. He has also been vomiting over the past hour. His temperature is 36.7°C (98°F), pulse is 98/min, respirations are 22/min, and blood pressure is 140/80 mm Hg. He is lethargic and oriented only to person. Examination shows flushed skin. Fundoscopic examination shows bright red retinal veins. Serum studies show:
Na+ 138 mEq/L
K+ 3.5 mEq/L
Cl- 100 mEq/L
HCO3- 17 mEq/L
Creatinine 1.2 mg/dL
Urea nitrogen 19 mg/dL
Lactate 8.0 mEq/L (N = 0.5 - 2.2 mEq/L)
Glucose 75 mg/dL
Arterial blood gas analysis on room air shows a pH of 7.13. This patient's current presentation is most likely due to complications from treatment of which of the following conditions?
Q1118
A 63-year-old woman comes to the physician because of worsening shortness of breath, cough, and a 4-kg (8.8-lb) weight loss over the last year. She has no history of serious illness and takes no medications. She has smoked one pack of cigarettes daily for 35 years. Her temperature is 37°C (98.6°F), pulse is 92/min, respirations are 20/min, blood pressure is 124/78 mm Hg, and pulse oximetry on room air shows an oxygen saturation of 93%. Physical examination shows decreased breath sounds. A flow-volume loop obtained via pulmonary function testing is shown. Which of the following is the most likely cause of this patient's respiratory symptoms?
Q1119
A 30-year-old African American woman comes to the physician because of a 3-month history of increasing shortness of breath, cough, and intermittent fever. She works in a local factory that manufactures components for airplanes. She drinks 2–3 glasses of wine daily and has smoked half a pack of cigarettes daily for the past 5 years. Physical examination shows a purple rash on her cheeks and nose. An x-ray of the chest shows bilateral hilar adenopathy and a calcified nodule in the left lower lobe. A bronchoalveolar lavage shows a CD4:CD8 T-lymphocyte ratio of 10:1 (N=2:1). A biopsy of the nodule shows a noncaseating granuloma. Which of the following is the strongest predisposing factor for the development of this patient's condition?
Q1120
A 25-year-old man is in the middle of an ascent up a mountain, at an elevation of about 4,500 meters. This is the 4th day of his expedition. His friend notices that in the last few hours, he has been coughing frequently and appears to be short of breath. He has used his albuterol inhaler twice in the past 4 hours, but it does not seem to help. Within the past hour, he has coughed up some frothy, slightly pink sputum and is now complaining of nausea and headache. Other than his asthma, which has been well-controlled on a steroid inhaler, he is healthy. Which of the following is the most likely cause of this man’s symptoms?
Cardiology US Medical PG Practice Questions and MCQs
Question 1111: A 47-year-old woman comes to the physician because of a 1-month history of progressive weakness. She has had increased difficulty climbing stairs and standing from a seated position. She takes no medications. Neurologic examination shows weakness of the proximal muscles. Skin examination shows diffuse erythema of the upper back, posterior neck, and shoulders. A photograph of the patient's eye is shown. Antibodies against which of the following are most likely to be present in this patient?
A. Histones
B. Mi-2 protein (Correct Answer)
C. Centromeres
D. La protein
E. Scl-70 protein
Explanation: ***Mi-2 protein***
- The patient's presentation with **progressive proximal muscle weakness** and characteristic skin findings (**heliotrope rash** on the eyes and **Shawl sign** on the upper back/shoulders) is highly indicative of **dermatomyositis**.
- **Anti-Mi-2 antibodies** are highly specific for dermatomyositis, particularly in patients with classic skin findings.
*Histones*
- **Anti-histone antibodies** are most commonly associated with **drug-induced lupus erythematosus**.
- This patient has no history of medication use that would suggest a drug-induced lupus, and her symptoms are more consistent with dermatomyositis.
*Centromeres*
- **Anti-centromere antibodies** are characteristic of the **limited cutaneous systemic sclerosis** (CREST syndrome).
- This condition presents with diverse symptoms like **calcinosis**, **Raynaud's phenomenon**, **esophageal dysmotility**, **sclerodactyly**, and **telangiectasias**, which are not observed in this patient.
*La protein*
- **Anti-La (SS-B) antibodies** are associated with **Sjögren's syndrome**, an autoimmune disorder primarily affecting exocrine glands.
- While Sjögren's can present with fatigue, the prominent **proximal muscle weakness** and **dermatological signs** seen in this case are not typical of Sjögren's.
*Scl-70 protein*
- **Anti-Scl-70 antibodies** (anti-topoisomerase I) are associated with **diffuse cutaneous systemic sclerosis**.
- This condition is characterized by widespread skin thickening, **Raynod's phenomenon**, and significant internal organ involvement (e.g., lung fibrosis, renal crisis), which are not described in this patient.
Question 1112: A 12-year-old boy is brought by his mother to the emergency room because of a swollen, hot, and tender knee that he sustained after falling on his way home. He has never had a swollen joint before; however, he has had frequent nosebleeds throughout his life. His mother is worried because they live with her parents who are currently on blood thinners. Every morning she puts the blood thinner pill in the boy's grandfather's milk and was concerned that she may have switched it this morning. Family history reveals a number of uncles who have had bleeding disorders; however, the mother does not know the exact disorder suffered by these relatives. A hematologic panel reveals the following findings:
Bleeding time: Increased
Prothrombin time: 12 seconds
Partial thromboplastin time (PTT): 55 seconds
PTT after factor mixing study: 37 seconds
Which of the following most likely explains the abnormal partial thromboplastin time in this patient?
A. Inhibition of reductase enzyme
B. Antibodies to factor VIII
C. Activation of inhibitory factors
D. Mutation in factor VIII
E. Mutation in carrying protein (Correct Answer)
Explanation: ***Mutation in carrying protein***
- This scenario describes **von Willebrand disease**, characterized by an **increased bleeding time** and an **elevated PTT** that corrects with a mixing study. The **mutation in the von Willebrand factor (vWF) protein**, which carries and protects factor VIII, leads to its rapid degradation.
- The **normal PT** rules out common pathway or extrinsic pathway coagulation defects, while the prolonged PTT points to an intrinsic pathway issue. The family history of bleeding disorders and frequent nosebleeds further supports this diagnosis, as vWF is essential for **platelet adhesion** and stabilizing factor VIII.
*Inhibition of reductase enzyme*
- Inhibition of the **reductase enzyme** (specifically **vitamin K epoxide reductase**) by drugs like warfarin would lead to deficiencies in **vitamin K-dependent clotting factors (II, VII, IX, X)**.
- This would result in a **prolonged PT** (due to reduced factor VII) and often a prolonged PTT, which is not seen here as PT is normal.
*Antibodies to factor VIII*
- **Antibodies to factor VIII** (acquired hemophilia) would lead to a prolonged PTT that **would not correct** with a mixing study, as the inhibitor would neutralize the added factor VIII.
- While acquired hemophilia can lead to severe bleeding, the correction with the mixing study points away from an inhibitor.
*Activation of inhibitory factors*
- **Activation of inhibitory factors** (e.g., lupus anticoagulant) would typically result in a prolonged PTT that **does not correct** with a mixing study (or only partially corrects), similar to an acquired factor VIII inhibitor.
- The complete correction of PTT in the mixing study makes this option less likely.
*Mutation in factor VIII*
- A **mutation in factor VIII** itself (hemophilia A) would cause a **prolonged PTT** that **corrects with a mixing study**, as the added normal plasma would supply the missing factor VIII.
- However, in this case, the **increased bleeding time** and the mention of a "carrying protein" point more specifically to **von Willebrand disease**, where vWF helps stabilize factor VIII.
Question 1113: A 42-year-old man comes to the physician for a health maintenance examination. He has had generalized fatigue and muscle aches since his previous visit 6 months ago. He has hypertension and gastroesophageal reflux disease. Current medications include amlodipine and omeprazole. His temperature is 37.1°C (98.1°F), pulse is 88/min and blood pressure is 156/102 mm Hg. Physical examination shows no abnormalities. Serum studies show:
Na+ 143 mEq/L
K+ 2.3 mEq/L
Cl- 100 mEq/L
HCO3- 31 mEq/L
Urea nitrogen 14 mg/dL
Creatinine 1 mg/dL
His blood pressure medication is discontinued. One week later his plasma aldosterone concentration is 35 ng/dL (N=3.6 - 24.0 ng/dL) and plasma renin activity is 0.4 ng/mL/h (N=0.3 to 4.2 ng/mL/h). An oral sodium loading test over 3 days fails to reduce aldosterone. A contrast-enhanced CT scan of the abdomen and pelvis shows a 3-cm, homogenous, right-sided adrenal mass with rapid contrast washout. He is counseled about his treatment options and chooses to pursue surgery. Which of the following is the most appropriate next step in management?
A. Right adrenalectomy
B. Fludrocortisone suppression test
C. Adrenal vein sampling (Correct Answer)
D. Spironolactone therapy
E. Bilateral adrenalectomy
Explanation: ***Adrenal vein sampling***
- This patient presents with **hypokalemia**, **hypertension**, elevated **plasma aldosterone concentration** with suppressed **plasma renin activity**, and unsuppressed aldosterone after a sodium loading test, all highly suggestive of **primary hyperaldosteronism**.
- Given the **3-cm adrenal mass** on the right side and the patient's choice for surgery, **adrenal vein sampling (AVS)** is crucial to confirm that the right adrenal gland is the sole source of excess aldosterone production, ensuring that surgery will be curative.
*Right adrenalectomy*
- Although surgery on the right adrenal gland is the desired outcome, performing a **right adrenalectomy** without prior adrenal vein sampling is premature and potentially harmful.
- AVS is essential to differentiate between a unilateral aldosterone-producing adenoma and bilateral adrenal hyperplasia, as the latter would not be cured by unilateral surgery.
*Fludrocortisone suppression test*
- The **fludrocortisone suppression test** is used to confirm the diagnosis of primary hyperaldosteronism, but the diagnosis in this patient is already strongly supported by the elevated aldosterone-to-renin ratio and lack of suppression with the oral sodium loading test.
- This test would not help in localizing the source of aldosterone excess.
*Spironolactone therapy*
- **Spironolactone** is an **aldosterone antagonist** that can be used to manage primary hyperaldosteronism, especially in cases of bilateral adrenal hyperplasia or if surgery is contraindicated or declined.
- However, given the patient's desire for surgery and the presence of a unilateral mass, the goal is curative resection, which requires further localization with AVS.
*Bilateral adrenalectomy*
- **Bilateral adrenalectomy** is generally reserved for rare cases of bilateral adrenal hyperplasia that are unresponsive to medical therapy or when AVS confirms bilateral disease and surgery is absolutely necessary.
- Performing a bilateral adrenalectomy would lead to permanent **adrenal insufficiency**, requiring lifelong corticosteroid replacement, which is a major drawback.
Question 1114: A 68-year-old female presents to the emergency room with acute onset of dyspnea and hemoptysis. Her past medical history is unremarkable and she has had no prior surgeries. A ventilation-perfusion scan demonstrates a large perfusion defect that is not matched by a ventilation defect in the left lower lobe. Which of the following would you also expect to find in this patient:
A. Bradycardia
B. Increased inspiratory capacity
C. Claudication
D. Aortic dilation
E. Pleuritic chest pain (Correct Answer)
Explanation: ***Pleuritic chest pain***
- The presented symptoms (dyspnea, hemoptysis, V/Q scan showing unmatched perfusion defect) are highly suggestive of **pulmonary embolism (PE)**. **Pleuritic chest pain** is a common symptom of PE, resulting from inflammation of the pleura often associated with a pulmonary infarct.
- **Pleuritic chest pain** is classically described as sharp, localized pain that worsens with deep inspiration or coughing, which aligns with the potential for pleural irritation in PE.
*Bradycardia*
- **Tachycardia**, not bradycardia, is a common finding in pulmonary embolism, often due to the body's compensatory response to hypoxemia and increased cardiovascular strain.
- Bradycardia would be atypical and likely unrelated to the acute presentation of PE in a previously healthy individual.
*Increased inspiratory capacity*
- In a patient with an acute pulmonary embolism, the inspiratory capacity is more likely to be normal or **decreased** due to discomfort from pleuritic chest pain, dyspnea, and potential V/Q mismatch affecting lung mechanics.
- Increased inspiratory capacity is not a typical physiological response to an acute PE; instead, patients often experience **restrictive breathing patterns**.
*Claudication*
- **Claudication** refers to pain, usually in the legs, caused by too little blood flow during exercise; it typically indicates **peripheral artery disease**.
- While PE is a thrombotic event, claudication is a symptom of chronic arterial insufficiency and is not directly related to acute pulmonary embolism.
*Aortic dilation*
- **Aortic dilation** is associated with conditions like aortic aneurysm or Marfan syndrome and is not a direct consequence or expected finding in acute pulmonary embolism.
- There is no pathophysiological link between acute PE and the immediate development or presence of aortic dilation.
Question 1115: A 45-year-old African American woman presents to her family physician for a routine examination. Past medical history is positive for amyloidosis and non-rhythm-based cardiac abnormalities secondary to the amyloidosis. Which of the following cardiac parameters would be expected in this patient?
A. Increased ejection fraction and decreased compliance
B. Preserved ejection fraction and increased compliance
C. Preserved ejection fraction and decreased compliance (Correct Answer)
D. Increased ejection fraction and increased compliance
E. Decreased ejection fraction and normal compliance
Explanation: ***Preserved ejection fraction and decreased compliance***
- Cardiac amyloidosis typically leads to **restrictive cardiomyopathy**, where amyloid deposits stiffen the ventricular walls.
- This stiffness impairs the heart's ability to fill properly (**decreased compliance**) but often maintains contractility and thus a **preserved ejection fraction** in the early stages, classifying it as **heart failure with preserved ejection fraction (HFpEF)**.
*Increased ejection fraction and decreased compliance*
- While **decreased compliance** is characteristic of cardiac amyloidosis, an **increased ejection fraction** is generally not expected in this condition.
- A true increase in ejection fraction is rare and not a primary feature of restrictive physiology; rather, the heart struggles to fill, but ejects a normal percentage of the reduced filled volume.
*Preserved ejection fraction and increased compliance*
- **Increased compliance** means the heart chambers are easily stretched and filled, which is the opposite of what occurs in cardiac amyloidosis.
- Patients with amyloidosis have stiff hearts that are difficult to fill, leading to **decreased compliance**.
*Increased ejection fraction and increased compliance*
- Neither **increased ejection fraction** nor **increased compliance** is consistent with cardiac amyloidosis, which is characterized by a stiff, poorly filling ventricle.
- This combination would suggest a hyperdynamic heart with excellent filling, not restrictive cardiomyopathy.
*Decreased ejection fraction and normal compliance*
- While later stages of cardiac amyloidosis can lead to a **decreased ejection fraction** due to severe myocardial dysfunction, it is typically preceded by a stage with **preserved ejection fraction**.
- **Normal compliance** is inconsistent with amyloid infiltration, which inherently reduces the heart's ability to stretch and fill.
Question 1116: A 34-year-old man comes to the physician for a routine health maintenance examination. He was diagnosed with HIV 8 years ago. He is currently receiving triple antiretroviral therapy. He is sexually active and uses condoms consistently. He is planning a trip to Thailand with his partner to celebrate his 35th birthday in 6 weeks. His last tetanus and diphtheria booster was given 4 years ago. He received three vaccinations against hepatitis B 5 years ago. He had chickenpox as a child. Other immunization records are unknown. Vital signs are within normal limits. Cardiopulmonary examination shows no abnormalities. Leukocyte count shows 8,700/mm3, and CD4+ T-lymphocyte count is 480 cells/mm3 (Normal ≥ 500); anti-HBs is 150 mIU/mL. Which of the following recommendations is most appropriate at this time?
A. Yellow fever vaccine
B. Hepatitis B vaccine
C. Tetanus, diphtheria, pertussis vaccine (Tdap)
D. Measles, mumps, rubella vaccine
E. No vaccination (Correct Answer)
Explanation: ***Correct: No vaccination***
- Given the patient's current immunization status and clinical scenario, **none of the listed vaccines are indicated at this time**.
- His CD4+ count of 480 cells/mm³ indicates relatively preserved immune function on effective antiretroviral therapy.
- His **anti-HBs level of 150 mIU/mL** demonstrates **adequate hepatitis B immunity** (protective level ≥10 mIU/mL).
- His **tetanus-diphtheria booster was given 4 years ago**, and routine boosters are recommended every **10 years**, so he is not due for another 6 years.
*Incorrect: Yellow fever vaccine*
- **Thailand is not a yellow fever endemic country**, so yellow fever vaccination is **not required or recommended** for travel there.
- Yellow fever vaccine is a **live attenuated vaccine** that can be given to HIV-positive patients with **CD4+ counts ≥200 cells/mm³** when travel to endemic areas (parts of Africa and South America) is necessary.
- Since the patient has a CD4+ count of 480 and Thailand doesn't require this vaccine, this is not applicable.
*Incorrect: Hepatitis B vaccine*
- The patient's **anti-HBs level of 150 mIU/mL** indicates **adequate protective immunity** against hepatitis B.
- A level ≥10 mIU/mL is considered protective, so **no booster is needed**.
*Incorrect: Tetanus, diphtheria, pertussis vaccine (Tdap)*
- **Tetanus-diphtheria boosters are recommended every 10 years**.
- The patient received his last booster **4 years ago**, so he is **not due** for another booster at this time.
- There is no specific indication for **pertussis vaccination** (e.g., pregnancy, close contact with infants).
*Incorrect: Measles, mumps, rubella vaccine*
- **MMR is a live attenuated vaccine** that is **contraindicated** in HIV-positive individuals with **CD4+ counts <200 cells/mm³**.
- While this patient's CD4+ count is 480, MMR should only be given to HIV patients if they lack immunity and have CD4 ≥200.
- There is **no documented need** for MMR based on the clinical scenario provided, and his immunity status to these infections is unknown.
- Without evidence of susceptibility or specific exposure risk, vaccination is not indicated.
Question 1117: Two days after admission to the hospital, a 74-year-old man develops confusion and headache. He has also been vomiting over the past hour. His temperature is 36.7°C (98°F), pulse is 98/min, respirations are 22/min, and blood pressure is 140/80 mm Hg. He is lethargic and oriented only to person. Examination shows flushed skin. Fundoscopic examination shows bright red retinal veins. Serum studies show:
Na+ 138 mEq/L
K+ 3.5 mEq/L
Cl- 100 mEq/L
HCO3- 17 mEq/L
Creatinine 1.2 mg/dL
Urea nitrogen 19 mg/dL
Lactate 8.0 mEq/L (N = 0.5 - 2.2 mEq/L)
Glucose 75 mg/dL
Arterial blood gas analysis on room air shows a pH of 7.13. This patient's current presentation is most likely due to complications from treatment of which of the following conditions?
A. Acute coronary syndrome
B. Diabetic ketoacidosis
C. Hypertensive crisis (Correct Answer)
D. Seizure disorder
E. Septic shock
Explanation: ***Hypertensive crisis***
- This patient's presentation is most consistent with **cyanide toxicity from sodium nitroprusside** treatment of hypertensive crisis.
- Sodium nitroprusside is commonly used for rapid blood pressure reduction in hypertensive emergencies but releases cyanide as a metabolite, especially with prolonged use (>48-72 hours) or in patients with renal dysfunction.
- Classic features of cyanide toxicity include: **bright red/cherry-red retinal veins** (due to impaired oxygen extraction by tissues), **flushed skin**, **severe lactic acidosis** (lactate 8.0 mEq/L with high anion gap metabolic acidosis), altered mental status, headache, and vomiting.
- Cyanide inhibits cytochrome c oxidase in the mitochondrial electron transport chain, causing **cellular hypoxia despite adequate oxygen delivery**, leading to anaerobic metabolism and lactic acidosis.
- Treatment involves stopping nitroprusside and administering **hydroxocobalamin or sodium thiosulfate** as antidotes.
*Acute coronary syndrome*
- Would present with chest pain, ECG changes, and elevated cardiac biomarkers (troponin).
- Lactic acidosis can occur in cardiogenic shock, but the **cherry-red retinal veins and flushed skin** are not features of ACS.
- Treatment of ACS (anticoagulation, antiplatelet therapy) would not cause this specific presentation.
*Diabetic ketoacidosis*
- Would show **hyperglycemia** (typically >250 mg/dL), not normal glucose (75 mg/dL).
- Would have **ketonemia and ketonuria**, elevated anion gap, but not the cherry-red retinal findings.
- Treatment with insulin would lower, not cause, lactic acidosis.
*Septic shock*
- Can cause lactic acidosis and altered mental status but typically presents with **fever or hypothermia, hypotension**, and elevated white blood cell count.
- Would not cause the characteristic **cherry-red retinal veins**.
- Treatment of sepsis (antibiotics, fluids) would not produce this toxic presentation.
*Seizure disorder*
- Post-ictal confusion can occur, but seizures cause **transient lactic acidosis** that typically resolves within 60-90 minutes.
- Would not explain the **persistent severe lactic acidosis (8.0 mEq/L), cherry-red retinal veins, or flushed skin**.
- Antiepileptic drugs do not cause cyanide toxicity or this metabolic picture.
Question 1118: A 63-year-old woman comes to the physician because of worsening shortness of breath, cough, and a 4-kg (8.8-lb) weight loss over the last year. She has no history of serious illness and takes no medications. She has smoked one pack of cigarettes daily for 35 years. Her temperature is 37°C (98.6°F), pulse is 92/min, respirations are 20/min, blood pressure is 124/78 mm Hg, and pulse oximetry on room air shows an oxygen saturation of 93%. Physical examination shows decreased breath sounds. A flow-volume loop obtained via pulmonary function testing is shown. Which of the following is the most likely cause of this patient's respiratory symptoms?
A. Unilateral mainstem obstruction
B. Chronic asthma
C. Idiopathic pulmonary fibrosis
D. Chronic obstructive pulmonary disease (Correct Answer)
E. Endotracheal neoplasm
Explanation: ***Chronic obstructive pulmonary disease***
* The patient's long history of **smoking** (35 pack-years) and presentation with **shortness of breath**, **cough**, and **weight loss** are classic clinical features of COPD. The flow-volume loop, while not provided, is expected to show an **obstructive pattern** with decreased expiratory flow.
* **Decreased breath sounds** on examination and **hypoxemia** (SpO2 93%) further support the diagnosis of COPD, indicating significant airflow limitation and gas exchange impairment.
*Unilateral mainstem obstruction*
* A unilateral mainstem obstruction would typically cause diminished or absent breath sounds **only on the affected side**, whereas the description mentions decreased breath sounds generally, suggesting a more widespread process.
* The **flow-volume loop pattern** for a fixed upper airway obstruction is different from what would be expected in a diffuse obstructive lung disease like COPD.
*Chronic asthma*
* While asthma can cause **shortness of breath** and **cough**, chronic asthma severe enough to cause **weight loss** and persistent hypoxemia, especially in an older patient with a heavy smoking history, is less likely than COPD.
* Asthma is characterized by **reversible airflow obstruction**, which is not typical of the long-standing, progressive nature described here.
*Idiopathic pulmonary fibrosis*
* Idiopathic pulmonary fibrosis (IPF) is a **restrictive lung disease**, meaning it would present with a restrictive pattern on the flow-volume loop, characterized by reduced lung volumes. The patient's symptoms are more consistent with an obstructive process.
* IPF typically presents with **bibasilar crackles** on physical examination and is not typically associated with decreased breath sounds in the way COPD is.
*Endotracheal neoplasm*
* An endotracheal neoplasm would cause an **upper airway obstruction**, leading to symptoms like stridor, hoarseness, and dyspnea. The flow-volume loop would show a characteristic pattern of **fixed or variable upper airway obstruction**.
* The patient's primary symptoms, imaging findings, and flow-volume loop pattern are more consistent with widespread bronchial disease rather than a localized upper airway mass.
Question 1119: A 30-year-old African American woman comes to the physician because of a 3-month history of increasing shortness of breath, cough, and intermittent fever. She works in a local factory that manufactures components for airplanes. She drinks 2–3 glasses of wine daily and has smoked half a pack of cigarettes daily for the past 5 years. Physical examination shows a purple rash on her cheeks and nose. An x-ray of the chest shows bilateral hilar adenopathy and a calcified nodule in the left lower lobe. A bronchoalveolar lavage shows a CD4:CD8 T-lymphocyte ratio of 10:1 (N=2:1). A biopsy of the nodule shows a noncaseating granuloma. Which of the following is the strongest predisposing factor for the development of this patient's condition?
A. Exposure to beryllium
B. Alcohol consumption
C. Exposure to acid-fast bacilli
D. Race (Correct Answer)
E. Smoking
Explanation: ***Race***
- **African Americans** have a significantly higher incidence and prevalence of **sarcoidosis** compared to other racial groups.
- They also tend to experience more severe disease and a higher risk of chronicity and multiorgan involvement.
*Exposure to beryllium*
- **Berylliosis** is a granulomatous disease that can mimic sarcoidosis, especially with lung involvement and noncaseating granulomas.
- However, the overall clinical picture, including the widespread organ involvement implied by the rash and the specific CD4:CD8 ratio, points more strongly to sarcoidosis.
*Alcohol consumption*
- While chronic alcohol consumption can affect immune function and organ health, it is **not a recognized predisposing factor** for sarcoidosis development.
- There is no direct causal link between alcohol intake and sarcoidosis.
*Exposure to acid-fast bacilli*
- Exposure to **acid-fast bacilli** (e.g., *Mycobacterium tuberculosis*) causes **tuberculosis**, which is characterized by **caseating granulomas**.
- This patient's biopsy shows **noncaseating granulomas**, differentiating it from tuberculosis.
*Smoking*
- Smoking is generally linked to **worse outcomes** in sarcoidosis but is not considered a primary predisposing factor for its development.
- Some studies even suggest a potential inverse relationship or no significant association with incidence.
Question 1120: A 25-year-old man is in the middle of an ascent up a mountain, at an elevation of about 4,500 meters. This is the 4th day of his expedition. His friend notices that in the last few hours, he has been coughing frequently and appears to be short of breath. He has used his albuterol inhaler twice in the past 4 hours, but it does not seem to help. Within the past hour, he has coughed up some frothy, slightly pink sputum and is now complaining of nausea and headache. Other than his asthma, which has been well-controlled on a steroid inhaler, he is healthy. Which of the following is the most likely cause of this man’s symptoms?
A. An acute asthma exacerbation
B. Non-cardiogenic pulmonary edema (Correct Answer)
C. Pneumothorax
D. Pulmonary embolism
E. Acute heart failure
Explanation: ***Non-cardiogenic pulmonary edema***
- The patient's symptoms of **dyspnea**, cough, and **frothy, pink sputum** at high altitude (4,500 meters) are classic signs of **High-Altitude Pulmonary Edema (HAPE)**, a form of non-cardiogenic pulmonary edema.
- The headache and nausea are consistent with **acute mountain sickness**, which often precedes HAPE, and the ineffectiveness of albuterol points away from asthma.
*An acute asthma exacerbation*
- While the patient has a history of asthma, the **frothy, pink sputum** is atypical for asthma and strongly suggests alveolar fluid.
- The ineffectiveness of albuterol, a bronchodilator, further suggests a cause other than **bronchoconstriction** as the primary issue.
*Pneumothorax*
- A pneumothorax typically presents with **sudden onset unilateral pleuritic chest pain** and dyspnea, which can be severe.
- It would not usually cause frothy, pink sputum and is not directly linked to high altitude in the absence of trauma.
*Pulmonary embolism*
- A pulmonary embolism often causes **sudden onset dyspnea, pleuritic chest pain, and sometimes hemoptysis**, but **pink, frothy sputum** is less common.
- There are no risk factors for PE mentioned, such as prolonged immobility or recent surgery.
*Acute heart failure*
- While acute heart failure can cause **pulmonary edema with frothy, pink sputum**, the patient is a young, otherwise healthy man with no cardiac risk factors.
- The context of **high altitude** strongly points to HAPE over acute heart failure as the cause of pulmonary edema.
