A 48-year-old man comes to the physician because of a 1-month history of a productive cough. He has daily yellowish sputum with occasional streaks of blood in it. Twelve years ago, he was treated for pulmonary tuberculosis for 6 months. He has hypertension and coronary artery disease. He does not smoke or drink alcohol. Current medications include metoprolol, clopidogrel, rosuvastatin, and enalapril. He appears thin. His temperature is 37.2°C (99°F), pulse is 98/min, and blood pressure is 138/92 mm Hg. Pulmonary examination shows inspiratory crackles at the right infraclavicular area. His hemoglobin concentration is 12.2 g/dL, leukocyte count is 11,300/mm3, and erythrocyte sedimentation rate is 38 mm/h. Urinalysis is normal. An x-ray of his chest is shown. Which of the following is most likely to be seen on further evaluation of the patient?
Q102
A 33-year-old African American woman presents to the clinic complaining of pain and swelling of her hands and wrists for the past 5 months. The symptoms are worse in the morning and are associated with stiffness that lasts about 15 minutes. She also complains of profound fatigue and decreased appetite. She is sexually active with one partner in a monogamous relationship. Past medical history is unremarkable and she is taking oral contraceptives. She smokes 1–2 cigarettes per day and drinks alcohol socially on the weekends. Temperature is 37.2°C (99.1°F), blood pressure is 130/82 mm Hg, pulse is 76/min, and respirations are 12/min. Physical examination reveals wrists that are tender to palpation, warm, and mildly swollen. Several metacarpophalangeal and proximal interphalangeal joints on both hands are also tender. Hand and wrist strength is 5/5 bilaterally. A non-tender ulcer on the buccal mucosa is also noted. When asked about it, the patient reports that it has been there for several months and does not bother her. Laboratory results are as follows:
Complete blood count
Hemoglobin 10.3 g/dL
Platelets 90,000/mm3
Leukocytes 6,700/mm3
Blood urea nitrogen 16 mg/dL
Creatinine 2.1 mg/dL
Urinalysis
Blood 10–20 red blood cells/hpf
Protein 2+ protein
B-HCG Negative
Which of the following is the most likely diagnosis in this patient?
Q103
A 62-year-old man presents to the physician because of difficulty initiating urination, terminal dribbling of urine, and bone pain for 3 months. He has no medical history of serious illness, and he currently takes no medications. His father had prostate cancer at age 58. His vital signs are within normal limits. The physical examination shows tenderness over the lower lumbar vertebrae and the right pelvis. The digital rectal exam (DRE) shows a prostate size equivalent to 2 finger pads with a hard nodule. The laboratory tests show the following results:
Serum
Prostate-specific antigen (PSA) 15 ng/mL
Testosterone 350 ng/mL (N=270–1070 ng/mL)
The prostate biopsy confirms the presence of prostate cancer with aggressive histologic features. The MRI shows local extension of the tumor. The radionuclide bone scan shows multiple metastatic sites. Which of the following is the most appropriate next step in management?
Q104
A 45-year-old woman comes to the physician because of shortness of breath while lying on her back over the past month. During this period, she has also had several episodes of bloody coughing. The patient reports that she had a heart problem when she was a child that was treated with antibiotics. She emigrated to the US from Russia 5 years ago. There is no family history of serious illness. Pulmonary examination shows crackles at both lung bases. Cardiac examination is shown. An ECG shows tachycardia and no P waves. Which of the following is the most likely diagnosis?
Q105
A previously healthy 48-year-old man comes to the physician for a 3-month history of myalgias and recurrent episodes of retrosternal chest pain and dizziness. He has had a 5-kg (11-lb) weight loss during this period. His temperature is 39.1°C (102.3°F), pulse is 90/min, and blood pressure is 160/102 mm Hg. Physical examination shows lacy, purplish discoloration of the skin with multiple erythematous, tender subcutaneous nodules on the lower legs. Some of the nodules have central ulcerations. Serum studies show an erythrocyte sedimentation rate of 76 mg/dL and creatinine level of 1.8 mg/dL. Renal MR angiography shows irregular areas of dilation and constriction in the renal arteries bilaterally. Further evaluation of this patient is most likely to show which of the following?
Q106
A previously healthy 35-year-old woman comes to the emergency department because of a sudden onset of difficulty breathing that began when she woke up that morning. She also reports a dry cough and chest pain that is worse with inspiration. She does not smoke, drink alcohol, or use illicit drugs. Her only medication is an oral contraceptive. Her temperature is 38°C (100.4°F), pulse is 90/min, respirations are 22/min, and blood pressure is 120/70 mm Hg. Oxygen saturation is 93% on room air. Physical examination is unremarkable. An ECG shows non-specific ST segment changes. An x-ray of the chest shows no abnormalities. In addition to oxygen supplementation, which of the following is the most appropriate next step in management?
Q107
A 12-year-old boy presents with a 3-day history of frothy brown urine. He does not complain of any other symptoms. He notes that 3 weeks ago he had a fever with a sore throat, but he did not receive any treatment at the time. His blood pressure is 152/94 mm Hg, heart rate is 72/min, respiratory rate is 15/min, and temperature is 37.0°C (98.6°F). Review of his medical record shows that his blood pressure was 118/74 mm Hg just 4 weeks ago. Laboratory analysis reveals elevated serum creatinine, hematuria with RBC casts, and elevated urine protein without frank proteinuria. What laboratory test can confirm the most likely diagnosis in this patient?
Q108
A 64-year-old woman comes to the physician because of worsening intermittent nausea and burning pain in her upper abdomen for 4 hours. She has not had retrosternal chest pain, shortness of breathing, or vomiting. She has hypertension and type 2 diabetes mellitus. She has smoked one pack of cigarettes daily for 20 years. Her only medications are lisinopril and insulin. Her temperature is 37°C (98.6°F), pulse is 90/min, respirations are 12/min, and blood pressure is 155/75 mm Hg. The lungs are clear to auscultation. The abdomen is soft, with mild tenderness to palpation of the epigastrium but no guarding or rebound. Bowel sounds are normal. An ECG is shown. This patient's current condition is most likely to cause which of the following findings on cardiac examination?
Q109
A 78-year-old male has been hospitalized for the past 3 days after undergoing a revision left total hip replacement. Over the past several hours, the nursing staff reports that the patient has exhibited fluctuating periods of intermittent drowsiness and confusion where he has been speaking to nonexistent visitors in his hospital room. The patient's daughter is present at bedside and reports that the patient lives alone and successfully manages his own affairs without assistance. Which of the following is most likely true of this patient's current condition?
Q110
Eight hours after undergoing successful cholecystectomy, a 65-year-old man with scoliosis complains of shortness of breath. Respirations are 28/min and pulse oximetry on room air shows an oxygen saturation of 85%. Physical examination shows kyphotic deformation of the thorax. Cardiopulmonary examination shows intercostal retractions and diminished breath sounds on the left side. There is trace pedal edema bilaterally. An x-ray of the chest shows bilateral fluffy infiltrates, and the cardiac silhouette is shifted slightly to the left side. Which of the following is the most likely explanation for this patient's hypoxia?
Cardiology US Medical PG Practice Questions and MCQs
Question 101: A 48-year-old man comes to the physician because of a 1-month history of a productive cough. He has daily yellowish sputum with occasional streaks of blood in it. Twelve years ago, he was treated for pulmonary tuberculosis for 6 months. He has hypertension and coronary artery disease. He does not smoke or drink alcohol. Current medications include metoprolol, clopidogrel, rosuvastatin, and enalapril. He appears thin. His temperature is 37.2°C (99°F), pulse is 98/min, and blood pressure is 138/92 mm Hg. Pulmonary examination shows inspiratory crackles at the right infraclavicular area. His hemoglobin concentration is 12.2 g/dL, leukocyte count is 11,300/mm3, and erythrocyte sedimentation rate is 38 mm/h. Urinalysis is normal. An x-ray of his chest is shown. Which of the following is most likely to be seen on further evaluation of the patient?
A. Multiple lytic foci on skeletal scintigraphy
B. Positive c-ANCA test
C. Repositioning the patient causes the mass to move (Correct Answer)
D. Exposure to asbestos
E. Clusters of gram-positive cocci in sputum
Explanation: ***Repositioning the patient causes the mass to move***
- The patient's history of treated pulmonary tuberculosis and current symptoms (productive cough, hemoptysis, inspiratory crackles) are highly suggestive of a **mycetoma (fungus ball)** forming in a pre-existing lung cavity.
- A mycetoma is a mass of fungal hyphae, mucus, and cellular debris that sits freely within a lung cavity, often caused by *Aspergillus* species. Its defining characteristic is its ability to **shift position with changes in patient posture**.
*Multiple lytic foci on skeletal scintigraphy*
- This finding suggests **bone metastases**, commonly associated with lung malignancies (e.g., lung cancer).
- While lung cancer can cause similar respiratory symptoms, a history of TB and the typical chest X-ray appearance of a mycetoma in a cavity make this less likely.
*Positive c-ANCA test*
- A positive c-ANCA (antineutrophil cytoplasmic antibody) test is associated with **ANCA-associated vasculitides**, particularly **granulomatosis with polyangiitis (Wegener's)**, which affects the lungs, kidneys, and upper airways.
- The patient's presentation
is not typical for vasculitis; symptoms like glomerulonephritis, sinusitis, or skin lesions are usually prominent.
*Exposure to asbestos*
- Asbestos exposure is a risk factor for **mesothelioma** and **asbestosis**, which present with different clinical features (e.g., pleural effusion, interstitial lung disease).
- It does not directly explain a discrete mass in a pre-existing cavity with a history of TB reactivation.
*Clusters of gram-positive cocci in sputum*
- This suggests a **bacterial pneumonia** or **abscess** caused by an organism like *Staphylococcus aureus*.
- While bacterial infections are possible, the patient's subacute course over one month, history of TB, and likelihood of a pre-existing cavity make a fungal infection (mycetoma) more probable.
Question 102: A 33-year-old African American woman presents to the clinic complaining of pain and swelling of her hands and wrists for the past 5 months. The symptoms are worse in the morning and are associated with stiffness that lasts about 15 minutes. She also complains of profound fatigue and decreased appetite. She is sexually active with one partner in a monogamous relationship. Past medical history is unremarkable and she is taking oral contraceptives. She smokes 1–2 cigarettes per day and drinks alcohol socially on the weekends. Temperature is 37.2°C (99.1°F), blood pressure is 130/82 mm Hg, pulse is 76/min, and respirations are 12/min. Physical examination reveals wrists that are tender to palpation, warm, and mildly swollen. Several metacarpophalangeal and proximal interphalangeal joints on both hands are also tender. Hand and wrist strength is 5/5 bilaterally. A non-tender ulcer on the buccal mucosa is also noted. When asked about it, the patient reports that it has been there for several months and does not bother her. Laboratory results are as follows:
Complete blood count
Hemoglobin 10.3 g/dL
Platelets 90,000/mm3
Leukocytes 6,700/mm3
Blood urea nitrogen 16 mg/dL
Creatinine 2.1 mg/dL
Urinalysis
Blood 10–20 red blood cells/hpf
Protein 2+ protein
B-HCG Negative
Which of the following is the most likely diagnosis in this patient?
A. Gouty arthritis
B. Systemic lupus erythematosus (Correct Answer)
C. Disseminated gonococcal arthritis
D. Parvovirus B19 infection
E. Behcet disease
Explanation: ***Systemic lupus erythematosus***
- This patient presents with a constellation of symptoms that meet multiple **SLE diagnostic criteria** including **arthritis** (non-erosive, symmetric polyarthritis), **oral ulcers** (painless mucosal ulcers), **hematologic disorder** (anemia with Hgb 10.3 g/dL, thrombocytopenia with platelets 90,000/mm³), and **renal disorder** (elevated creatinine 2.1 mg/dL, proteinuria 2+, hematuria with 10-20 RBCs/hpf).
- The patient's demographic profile (young African American woman) significantly increases the pre-test probability for SLE, as the disease is more common and severe in this population.
- Constitutional symptoms like fatigue and decreased appetite are also common in SLE due to chronic inflammation.
*Gouty arthritis*
- Gout typically presents as **acute, monoarticular arthritis** with severe pain, often affecting the **first metatarsophalangeal joint** (podagra), which is not seen here.
- The polyarticular symmetric distribution, morning stiffness, and systemic manifestations (cytopenias, renal involvement, oral ulcers) are not characteristic of gout.
*Disseminated gonococcal arthritis*
- This condition presents with **migratory polyarthralgia**, **tenosynovitis**, and **dermatitis** (pustular skin lesions), usually following a **gonococcal infection**.
- The chronic 5-month duration, absence of recent infection symptoms, lack of skin lesions or tenosynovitis, and the presence of oral ulcers, cytopenias, and chronic renal disease make this diagnosis unlikely.
*Parvovirus B19 infection*
- **Parvovirus B19 infection** can cause **symmetric polyarthralgia/arthritis** and a **"slapped cheek" rash** or reticular rash in adults, sometimes mimicking rheumatoid arthritis.
- However, it typically causes an acute, self-limited illness, not a chronic 5-month presentation, and does not typically cause sustained thrombocytopenia, chronic painless oral ulcers, or significant renal involvement with elevated creatinine and proteinuria.
*Behcet disease*
- **Behcet disease** is characterized by **recurrent oral and genital ulcers**, **ocular involvement** (uveitis), and **skin lesions** (erythema nodosum, papulopustular lesions).
- While oral ulcers are present, the significant cytopenias (anemia and thrombocytopenia), chronic symmetric polyarthritis, and clear evidence of lupus nephritis (elevated creatinine, hematuria, proteinuria) are not typical features of Behcet disease.
Question 103: A 62-year-old man presents to the physician because of difficulty initiating urination, terminal dribbling of urine, and bone pain for 3 months. He has no medical history of serious illness, and he currently takes no medications. His father had prostate cancer at age 58. His vital signs are within normal limits. The physical examination shows tenderness over the lower lumbar vertebrae and the right pelvis. The digital rectal exam (DRE) shows a prostate size equivalent to 2 finger pads with a hard nodule. The laboratory tests show the following results:
Serum
Prostate-specific antigen (PSA) 15 ng/mL
Testosterone 350 ng/mL (N=270–1070 ng/mL)
The prostate biopsy confirms the presence of prostate cancer with aggressive histologic features. The MRI shows local extension of the tumor. The radionuclide bone scan shows multiple metastatic sites. Which of the following is the most appropriate next step in management?
A. Radiation therapy
B. Radical prostatectomy
C. Androgen deprivation therapy (Correct Answer)
D. Active surveillance
E. Chemotherapy
Explanation: ***Androgen deprivation therapy***
- This patient presents with **metastatic prostate cancer**, as indicated by the bone pain, positive bone scan, elevated PSA, and aggressive histologic features with local extension. **Androgen deprivation therapy (ADT)** is the cornerstone of treatment for metastatic prostate cancer because prostate cancer growth is often **androgen-dependent**.
- ADT aims to reduce androgen levels (primarily testosterone) which can be achieved through surgical castration (orchiectomy) or medical castration using GnRH agonists or antagonists, leading to tumor regression and symptom palliation.
*Radiation therapy*
- **External beam radiation therapy** is typically used for localized prostate cancer or for treating localized metastatic sites to alleviate pain.
- It is **not sufficient as a monotherapy** for **widespread metastatic disease** as seen in this patient, where systemic treatment is required.
*Radical prostatectomy*
- **Radical prostatectomy** is a surgical procedure to remove the prostate gland and is a curative option for **localized prostate cancer**.
- It is **contraindicated and ineffective** for **metastatic disease** that has spread beyond the prostate, as it cannot remove all cancer cells in other parts of the body.
*Active surveillance*
- **Active surveillance** is an appropriate management strategy for **low-risk, localized prostate cancer** in older patients or those with significant comorbidities, where the risks of treatment outweigh the benefits.
- This patient has **aggressive, metastatic disease** with symptomatic bone pain, making active surveillance an entirely inappropriate and harmful choice.
*Chemotherapy*
- **Chemotherapy** is generally reserved for **castration-resistant prostate cancer (CRPC)**, meaning the cancer has progressed despite androgen deprivation therapy.
- While chemotherapy can be used later in the disease course, initial management for **hormone-sensitive metastatic prostate cancer** like this case is typically ADT.
Question 104: A 45-year-old woman comes to the physician because of shortness of breath while lying on her back over the past month. During this period, she has also had several episodes of bloody coughing. The patient reports that she had a heart problem when she was a child that was treated with antibiotics. She emigrated to the US from Russia 5 years ago. There is no family history of serious illness. Pulmonary examination shows crackles at both lung bases. Cardiac examination is shown. An ECG shows tachycardia and no P waves. Which of the following is the most likely diagnosis?
A. Mitral valve stenosis (Correct Answer)
B. Aortic valve regurgitation
C. Pulmonary valve regurgitation
D. Aortic valve stenosis
E. Pulmonary valve stenosis
Explanation: ***Mitral valve stenosis***
- The patient's history of a childhood heart problem treated with antibiotics, followed by shortness of breath while lying flat (**orthopnea**) and bloody coughing (**hemoptysis**), strongly suggests **rheumatic heart disease** leading to mitral stenosis. The **tachycardia and absence of P waves** on ECG likely indicate **atrial fibrillation**, a common complication of mitral stenosis due to left atrial enlargement.
- **Pulmonary crackles** are consistent with **pulmonary congestion** and **pulmonary hypertension**, which are direct consequences of severe mitral stenosis due to impaired blood flow from the left atrium to the left ventricle.
*Aortic valve regurgitation*
- This condition is often associated with symptoms like **palpitations**, **angina**, and a **water-hammer pulse**, which are not described here.
- While it can lead to heart failure symptoms, the historical context of childhood heart issues treated with antibiotics is more indicative of rheumatic fever affecting the mitral valve.
*Pulmonary valve regurgitation*
- This is a rare condition, often asymptomatic, or presenting with symptoms of right-sided heart failure like **peripheral edema** and **ascites**, which are not mentioned.
- It is rarely caused by rheumatic heart disease, and the significant pulmonary congestion and hemoptysis are not typical primary findings.
*Aortic valve stenosis*
- Symptoms usually include a triad of **angina**, **syncope**, and **dyspnea on exertion** (DOE), which differ from the orthopnea and hemoptysis described.
- Physical examination would typically reveal a **crescendo-decrescendo systolic murmur** loudest at the right upper sternal border, not just crackles.
*Pulmonary valve stenosis*
- This congenital condition often presents with **exertional dyspnea**, **fatigue**, and signs of right ventricular hypertrophy, but not typically with orthopnea and hemoptysis as prominent features.
- Rheumatic heart disease rarely affects the pulmonary valve significantly.
Question 105: A previously healthy 48-year-old man comes to the physician for a 3-month history of myalgias and recurrent episodes of retrosternal chest pain and dizziness. He has had a 5-kg (11-lb) weight loss during this period. His temperature is 39.1°C (102.3°F), pulse is 90/min, and blood pressure is 160/102 mm Hg. Physical examination shows lacy, purplish discoloration of the skin with multiple erythematous, tender subcutaneous nodules on the lower legs. Some of the nodules have central ulcerations. Serum studies show an erythrocyte sedimentation rate of 76 mg/dL and creatinine level of 1.8 mg/dL. Renal MR angiography shows irregular areas of dilation and constriction in the renal arteries bilaterally. Further evaluation of this patient is most likely to show which of the following?
A. Presence of anti-myeloperoxidase antibodies in the serum
B. Presence of anti-proteinase 3 antibodies in the serum
C. Pulmonary artery microaneurysms on pulmonary angiography
D. Transmural inflammation with fibrinoid necrosis on arterial biopsy (Correct Answer)
E. Multinucleated giant cells with elastic membrane fragmentation on arterial biopsy
Explanation: ***Transmural inflammation with fibrinoid necrosis on arterial biopsy***
- The patient's symptoms (myalgias, recurrent chest pain, dizziness, weight loss, fever, hypertension, elevated ESR, acute kidney injury) combined with **livedo reticularis** and **subcutaneous nodules with ulcerations** are highly suggestive of **polyarteritis nodosa (PAN)**, a medium-vessel vasculitis.
- Classic histological findings in PAN are **segmental transmural inflammation of medium-sized arteries**, often with **fibrinoid necrosis**, leading to luminal narrowing, thrombosis, or microaneurysm formation.
*Presence of anti-myeloperoxidase antibodies in the serum*
- **Anti-myeloperoxidase (MPO) antibodies** are associated with **microscopic polyangiitis** and **eosinophilic granulomatosis with polyangiitis (Churg-Strauss)**, which are small-vessel vasculitides, not typically presenting with the widespread systemic findings and medium-vessel involvement seen here.
- While these can cause renal involvement and systemic symptoms, the **cutaneous nodules with ulcerations** and **renal artery aneurysms/stenosis** are more characteristic of PAN, which is typically ANCA-negative.
*Presence of anti-proteinase 3 antibodies in the serum*
- **Anti-proteinase 3 (PR3) antibodies** are characteristic of **granulomatosis with polyangiitis (Wegener's)**, which is also a small-vessel vasculitis.
- Granulomatosis with polyangiitis predominantly affects the upper and lower respiratory tracts and kidneys, and classic findings like **nasal septal perforation** or **pulmonary nodules with cavitation** are absent.
*Pulmonary artery microaneurysms on pulmonary angiography*
- While aneurysms can occur in vasculitis, **pulmonary artery microaneurysms** are a less common or specific finding for PAN, which primarily affects medium-sized arteries in various organs, including renal, mesenteric, and skin arteries.
- The constellation of symptoms and the appearance of **renal artery irregular dilation and constriction** point more strongly to a systemic medium-vessel vasculitis like PAN, where such findings in the kidney are typical.
*Multinucleated giant cells with elastic membrane fragmentation on arterial biopsy*
- **Multinucleated giant cells** and **elastic membrane fragmentation** are characteristic histological features of **giant cell (temporal) arteritis** or **Takayasu arteritis**, both of which are large-vessel vasculitides.
- Giant cell arteritis typically affects older individuals and presents with symptoms like **headache**, **jaw claudication**, and **visual disturbances**, while Takayasu arteritis affects the aorta and its major branches, leading to pulse deficits, neither of which aligns with this patient's presentation.
Question 106: A previously healthy 35-year-old woman comes to the emergency department because of a sudden onset of difficulty breathing that began when she woke up that morning. She also reports a dry cough and chest pain that is worse with inspiration. She does not smoke, drink alcohol, or use illicit drugs. Her only medication is an oral contraceptive. Her temperature is 38°C (100.4°F), pulse is 90/min, respirations are 22/min, and blood pressure is 120/70 mm Hg. Oxygen saturation is 93% on room air. Physical examination is unremarkable. An ECG shows non-specific ST segment changes. An x-ray of the chest shows no abnormalities. In addition to oxygen supplementation, which of the following is the most appropriate next step in management?
A. Perform pulmonary angiography
B. Start noninvasive positive pressure ventilation
C. Measure fibrin degradation products (Correct Answer)
D. Administer ibuprofen
E. Order ventilation and perfusion scintigraphy
Explanation: ***Measure fibrin degradation products***
- This patient presents with **sudden-onset dyspnea**, **pleuritic chest pain**, **tachycardia**, **tachypnea**, and **hypoxemia**, along with a risk factor for **venous thromboembolism** (oral contraceptive use). These findings are highly suspicious for **pulmonary embolism (PE)**.
- Measuring **D-dimer (fibrin degradation product)** is the most appropriate **initial next step** in this clinical scenario as part of a stepwise diagnostic approach. While imaging (such as CT pulmonary angiography) would be definitive, D-dimer serves as a **rapid, non-invasive screening test** that can guide further management.
- A **negative D-dimer** in a patient with low-to-intermediate pretest probability effectively **rules out PE** (high negative predictive value), avoiding unnecessary radiation exposure from imaging. If positive, it would prompt definitive imaging.
- This approach is **cost-effective** and follows standard emergency department protocols for suspected PE.
*Perform pulmonary angiography*
- **Invasive pulmonary angiography** (catheter-based) is the historical **gold standard** for diagnosing PE but has been largely replaced by **CT pulmonary angiography (CTPA)**.
- It is **invasive** with associated risks (vascular injury, contrast reactions, bleeding) and is typically reserved for cases where non-invasive imaging is inconclusive or when intervention is planned simultaneously.
- This is **not an appropriate initial step** in the diagnostic workup.
*Start noninvasive positive pressure ventilation*
- This patient's **oxygen saturation is 93%** on room air, indicating **mild hypoxemia** that can be adequately managed with **supplemental oxygen** alone.
- **Noninvasive positive pressure ventilation (NIPPV)** is reserved for patients with **severe respiratory distress**, **acute respiratory failure**, or **refractory hypoxemia** (typically SpO2 <90% despite oxygen).
- There is no indication for NIPPV in this stable patient.
*Administer ibuprofen*
- **Ibuprofen** is an **NSAID** used for analgesia and anti-inflammatory effects, but it does **not address the underlying pathology** of suspected **pulmonary embolism**.
- While the patient has pleuritic chest pain, the priority is to **diagnose the potentially life-threatening condition** causing her acute symptoms, not merely provide symptomatic relief.
- Additionally, NSAIDs have antiplatelet effects that could complicate management if anticoagulation is needed.
*Order ventilation and perfusion scintigraphy*
- A **ventilation-perfusion (V/Q) scan** is an appropriate imaging study for diagnosing PE, particularly in patients with **normal chest X-ray**, **renal insufficiency** (cannot receive CT contrast), or **pregnancy**.
- However, in the **stepwise diagnostic approach** for suspected PE, **D-dimer testing should be performed first** as a rapid screening tool. If D-dimer is elevated, then imaging (V/Q scan or CTPA) would be the next step.
- Proceeding directly to V/Q scan **bypasses the screening step** that could potentially rule out PE without radiation exposure, making it less optimal as the immediate next step.
Question 107: A 12-year-old boy presents with a 3-day history of frothy brown urine. He does not complain of any other symptoms. He notes that 3 weeks ago he had a fever with a sore throat, but he did not receive any treatment at the time. His blood pressure is 152/94 mm Hg, heart rate is 72/min, respiratory rate is 15/min, and temperature is 37.0°C (98.6°F). Review of his medical record shows that his blood pressure was 118/74 mm Hg just 4 weeks ago. Laboratory analysis reveals elevated serum creatinine, hematuria with RBC casts, and elevated urine protein without frank proteinuria. What laboratory test can confirm the most likely diagnosis in this patient?
A. Antistreptolysin O (ASO) titer (Correct Answer)
B. Urine Gram stain
C. Urine electrolytes
D. Stool sample
E. Urine catecholamine assessment
Explanation: ***Antistreptolysin O (ASO) titer***
- A 3-week history of a sore throat followed by frothy brown urine, **hematuria with RBC casts**, and **hypertension** in a 12-year-old boy is highly suggestive of **post-streptococcal glomerulonephritis (PSGN)**.
- An elevated **ASO titer** indicates recent exposure to *Streptococcus pyogenes*, the causative agent of PSGN, confirming the diagnosis.
*Urine Gram stain*
- This test is used to detect bacterial infections in the urinary tract, which typically present with symptoms like **dysuria, frequency, and fever**, and often show bacteriuria rather than hematuria with RBC casts.
- While a urinary tract infection can cause hematuria, the presence of **RBC casts** and the preceding sore throat point away from a simple bacterial UTI.
*Urine electrolytes*
- While renal dysfunction can affect electrolyte balance, **urine electrolytes** are not a primary diagnostic tool for glomerulonephritis like PSGN.
- This test is more useful for assessing **fluid balance disorders** or specific tubular dysfunctions.
*Stool sample*
- A **stool sample** is primarily used to diagnose gastrointestinal infections or conditions affecting the bowel.
- There is no clinical indication in this patient's presentation (sore throat, frothy brown urine, hypertension, hematuria with RBC casts) that would suggest a gastrointestinal pathology as the cause of his renal symptoms.
*Urine catecholamine assessment*
- This test is used to screen for **pheochromocytoma**, a rare tumor of the adrenal glands that can cause hypertension.
- While the patient has new-onset hypertension, the history of a preceding sore throat and the presence of **hematuria with RBC casts** strongly argue against pheochromocytoma as the primary diagnosis.
Question 108: A 64-year-old woman comes to the physician because of worsening intermittent nausea and burning pain in her upper abdomen for 4 hours. She has not had retrosternal chest pain, shortness of breathing, or vomiting. She has hypertension and type 2 diabetes mellitus. She has smoked one pack of cigarettes daily for 20 years. Her only medications are lisinopril and insulin. Her temperature is 37°C (98.6°F), pulse is 90/min, respirations are 12/min, and blood pressure is 155/75 mm Hg. The lungs are clear to auscultation. The abdomen is soft, with mild tenderness to palpation of the epigastrium but no guarding or rebound. Bowel sounds are normal. An ECG is shown. This patient's current condition is most likely to cause which of the following findings on cardiac examination?
A. Decrescendo diastolic murmur
B. Muffled heart sounds
C. Atrial gallop (Correct Answer)
D. Ventricular gallop
E. Mid-systolic click
Explanation: ***Atrial gallop***
- The ECG findings in this clinical presentation suggest **acute myocardial ischemia/infarction**, which commonly leads to **left ventricular diastolic dysfunction** where the ventricle becomes stiff and non-compliant.
- In diastolic dysfunction, the atria must contract more forcefully to fill the stiff ventricle, producing a **pathological S4 heart sound (atrial gallop)** that occurs just before S1.
- An S4 is one of the earliest and most common findings in acute MI due to decreased ventricular compliance from ischemia.
*Decrescendo diastolic murmur*
- A decrescendo diastolic murmur is characteristic of **aortic regurgitation** or **pulmonic regurgitation**, which are valvular lesions not directly caused by acute myocardial ischemia.
- No clinical features suggest valvular disease (e.g., no wide pulse pressure for aortic regurgitation).
*Muffled heart sounds*
- Muffled heart sounds suggest **pericardial effusion**, as seen in **cardiac tamponade** or **pericarditis**.
- While post-MI complications can include pericarditis (Dressler syndrome), this typically occurs days to weeks after MI, not in the acute presentation, and is uncommon with modern MI management.
*Ventricular gallop*
- A ventricular gallop (**S3 heart sound**) indicates **systolic dysfunction** with **volume overload** and rapid ventricular filling, as seen in **severe heart failure** or **dilated cardiomyopathy**.
- While large MIs can cause systolic dysfunction, the S4 (from diastolic dysfunction due to ischemia) is the more immediate finding in acute MI before systolic failure develops.
*Mid-systolic click*
- A mid-systolic click is characteristic of **mitral valve prolapse**, a structural valve abnormality.
- This is not caused by or associated with acute myocardial ischemia.
Question 109: A 78-year-old male has been hospitalized for the past 3 days after undergoing a revision left total hip replacement. Over the past several hours, the nursing staff reports that the patient has exhibited fluctuating periods of intermittent drowsiness and confusion where he has been speaking to nonexistent visitors in his hospital room. The patient's daughter is present at bedside and reports that the patient lives alone and successfully manages his own affairs without assistance. Which of the following is most likely true of this patient's current condition?
A. Short-term memory is often impaired, with sparing of remote memory
B. Anticholinergic medications may alleviate his symptoms
C. Possible etiologies include infection, trauma, or polypharmacy (Correct Answer)
D. Beta-amyloid plaques and neurofibrillary tangles are pathologic findings associated with this condition
E. The condition is typically irreversible, representing a common complication of aging
Explanation: ***Possible etiologies include infection, trauma, or polypharmacy***
- The patient's presentation of **acute onset, fluctuating confusion, and visual hallucinations** following surgery strongly suggests **delirium**.
- Delirium is often caused by an underlying medical condition, such as **infection, trauma (like surgery), medication side effects (polypharmacy)**, metabolic derangements, or withdrawal.
*Short-term memory is often impaired, with sparing of remote memory*
- While memory impairment is common in delirium, particularly **attention and recent memory**, this statement is characteristic of **dementia**, where **short-term memory** is significantly affected while **remote memory** may be initially preserved.
- Delirium is primarily a disorder of **attention and arousal**, leading to intermittent confusion and disorientation rather than a primary global memory deficit.
*Anticholinergic medications may alleviate his symptoms*
- **Anticholinergic medications** are a *common cause or exacerbating factor* for delirium, especially in elderly patients, and would likely worsen his symptoms.
- Treatment for delirium involves identifying and addressing the **underlying cause**, not administering drugs that could precipitate or worsen it.
*Beta-amyloid plaques and neurofibrillary tangles are pathologic findings associated with this condition*
- **Beta-amyloid plaques** and **neurofibrillary tangles** are the characteristic neuropathological hallmarks of **Alzheimer's disease**, a type of dementia.
- These findings are *not directly associated with delirium*, which is an acute, generally reversible state of altered consciousness and cognition.
*The condition is typically irreversible, representing a common complication of aging*
- Delirium is an **acute** and often **reversible** condition, especially if the underlying cause is identified and treated promptly.
- It is a common and serious complication in older hospitalized patients, but it is **not an irreversible** process or a normal part of aging.
Question 110: Eight hours after undergoing successful cholecystectomy, a 65-year-old man with scoliosis complains of shortness of breath. Respirations are 28/min and pulse oximetry on room air shows an oxygen saturation of 85%. Physical examination shows kyphotic deformation of the thorax. Cardiopulmonary examination shows intercostal retractions and diminished breath sounds on the left side. There is trace pedal edema bilaterally. An x-ray of the chest shows bilateral fluffy infiltrates, and the cardiac silhouette is shifted slightly to the left side. Which of the following is the most likely explanation for this patient's hypoxia?
A. Embolus in the pulmonary artery
B. Collapsed alveoli (Correct Answer)
C. Bacterial infiltration of lung parenchyma
D. Fluid in the pleural space
E. Air trapped in the pleural space
Explanation: ***Collapsed alveoli***
- The patient's presentation with **shortness of breath**, **tachypnea**, **hypoxia** (SpO2 85%), **intercostal retractions**, and **diminished breath sounds**, especially in the context of recent abdominal surgery (cholecystectomy), strongly suggests **atelectasis** due to collapsed alveoli.
- **Fluffy infiltrates** on chest X-ray can be consistent with atelectasis, particularly in the lower lobes, and the kyphotic deformity (scoliosis) further predisposes the patient to poor lung expansion.
*Embolus in the pulmonary artery*
- While a **pulmonary embolism** can cause sudden shortness of breath and hypoxia post-surgery, the chest X-ray findings of **bilateral fluffy infiltrates** are not typical.
- Furthermore, **diminished breath sounds** and **intercostal retractions** are less characteristic of a PE compared to atelectasis.
*Bacterial infiltration of lung parenchyma*
- **Bacterial pneumonia** would typically present with fever, productive cough, and more localized infiltrates on chest X-ray, sometimes with consolidation.
- The acute onset within 8 hours post-surgery makes bacterial pneumonia less likely as the primary cause of hypoxia.
*Fluid in the pleural space*
- **Pleural effusion** would cause diminished breath sounds and potentially dyspnea, but the chest X-ray typically shows blunting of costophrenic angles and a meniscus sign, rather than diffuse "fluffy infiltrates."
- While some fluid could accumulate post-operatively, it doesn't fully explain the widespread nature of the "fluffy infiltrates" or the intercostal retractions as the primary cause of hypoxia.
*Air trapped in the pleural space*
- **Pneumothorax** (air in the pleural space) would lead to very diminished or absent breath sounds on the affected side and would typically show a visible pleural line and lung collapse on chest X-ray.
- The description of "bilateral fluffy infiltrates" and diffuse intercostal retractions is inconsistent with a simple pneumothorax.