A 62-year-old man is brought to the emergency department with a sudden onset of severe chest pain, that he describes as tearing. The pain started 90 minutes back and is now referring to the upper back. There is a history of essential hypertension for the past 17 years. The patient has smoked 20–30 cigarettes daily for the past 27 years. Vital signs reveal: temperature 36.8°C (98.2°F), heart rate 105/min, and blood pressure 192/91 mm Hg in the right arm and 159/81 mm Hg in the left arm. Pulses are absent in the right leg and diminished in the left. ECG shows sinus tachycardia, and chest X-ray shows a widened mediastinum. Transthoracic echocardiography shows an intimal flap arising from the ascending aorta and extended to the left subclavian artery. Intravenous morphine sulfate is started. Which of the following is the best next step in the management of this patient condition?
Q362
A 34-year-old G3P3 woman with a history of migraines presents with several weeks of headaches. The headaches are unlike her usual migraines and are worse in the morning. This morning she had an episode of emesis prompting her to seek medical care. She also has some right sided weakness which she believes is related to a new exercise routine. Her mother is a breast cancer survivor. Her medications include oral contraceptives and ibuprofen as needed, which has not helped her current headaches. She drinks 2-3 alcoholic drinks on the weekends and does not smoke. Physical examination is remarkable for bilateral papilledema. Motor exam is notable for upper and lower extremity strength 4/5 on the right and 5/5 on the left. Magnetic resonance venography demonstrates absent flow in the left venous sinuses. Which of the following predisposed this patient to her current condition?
Q363
A 52-year-old man presents to the emergency department with sudden-onset dyspnea, tachypnea, and chest pain. He works as a long-haul truck driver, and he informs you that he recently returned to the west coast from a trip to Tennessee. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type 2, and mild intellectual disability. He currently smokes 2 packs of cigarettes/day, drinks a 6-pack of beer/day, and he endorses a past history of injection drug use but currently denies any illicit drug use. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 23/min. His physical examination shows minimal bibasilar rales, but otherwise clear lungs on auscultation, grade 2/6 holosystolic murmur, and a benign abdominal physical examination. A computed tomography angiography (CTA) demonstrates a segmental pulmonary embolism (PE). Which of the following is the most appropriate treatment plan for this patient?
Q364
A 65-year-old male engineer presents to the office with shortness of breath on exertion and a dry cough that he has had for about a year. He is a heavy smoker with a 25-pack-years history. His vitals include: heart rate 95/min, respiratory rate 26/min, and blood pressure 110/75 mm Hg. On examination, he presents with nail clubbing and bilateral and persistent crackling rales. The chest radiograph shows basal reticulonodular symmetric images, with decreased lung fields. The pulmonary function tests show the following: diffusing capacity of the lungs for carbon monoxide (DLCO) is 43% and reference SaO2 is 94% and 72%, at rest and with exercise, respectively. What is the most likely diagnosis?
Q365
A 62-year-old man presents to his primary care physician because he is unhappy about his inability to tan this summer. He has been going to the beach with his family and friends, but he has remained pale. He has no other complaints except that he has been getting tired more easily, which he attributes to normal aging. Based on clinical suspicion a panel of tests are performed with the following results:
Hemoglobin: 11 g/dL
Leukocyte count: 5,370/mm^3
Platelet count: 168,000/mm^3
Mean corpuscular volume: 95 µm^3
Haptoglobin level: Decreased
Reticulocytes: 3%
Peripheral blood smear is also obtained and shown in the figure provided. Which of the following patient characteristics is consistent with the most likely cause of this patient's disease?
Q366
A 51-year-old woman is brought into the emergency department following a motor vehicle accident. She is unconscious and was intubated in the field. Past medical history is unknown. Upon arrival, she is hypotensive and tachycardic. Her temperature is 37.2°C (99.1°F), the pulse is 110/min, the respiratory rate is 22/min, and the blood pressure is 85/60 mm Hg. There is no evidence of head trauma, she withdraws to pain and her pupils are 2mm and reactive to light. Her heart has a regular rhythm without any murmurs or rubs and her lungs are clear to auscultation. Her abdomen is firm and distended with decreased bowel sounds. Her extremities are cool and clammy with weak, thready pulses. There is no peripheral edema. Of the following, what is the likely cause of her presentation?
Q367
Two weeks after undergoing an emergency cardiac catheterization for unstable angina pectoris, a 65-year-old man has decreased urinary output. He takes naproxen for osteoarthritis and was started on aspirin, clopidogrel, and metoprolol after the coronary intervention. His temperature is 38.1°C (100.5°F), pulse is 96/min, and blood pressure is 128/88 mm Hg. Examination shows mottled, reticulated purplish discoloration of the feet and ischemic changes on the right big toe. His leukocyte count is 16,500/mm3 with 56% segmented neutrophils, 12% eosinophils, 30% lymphocytes, and 2% monocytes. His serum creatinine concentration is 4.5 mg/dL. A photomicrograph of a kidney biopsy specimen is shown. Which of the following is the most likely cause of this patient's presentation?
Q368
A 25-year-old previously healthy woman is admitted to the hospital with progressively worsening shortness of breath. She reports a mild fever. Her vital signs at the admission are as follows: blood pressure 100/70 mm Hg, heart rate 111/min, respiratory rate 20/min, and temperature 38.1℃ (100.6℉); blood saturation on room air is 90%. Examination reveals a bilateral decrease of vesicular breath sounds and rales in the lower lobes. Plain chest radiograph demonstrates bilateral opacification of the lower lobes. Despite appropriate treatment, her respiratory status worsens. The patient is transferred to the intensive care unit and put on mechanical ventilation. Adjustment of which of the following ventilator settings will only affect the patient’s oxygenation?
Q369
A healthy 20-year-old African American man presents to the clinic for pre-participation sports physical for college football. He has no health complaints at this time. He has no recent history of illness or injury. He denies chest pain and palpitations. He reports no prior syncopal episodes. He had surgery 2 years ago for appendicitis. His mother is healthy and has an insignificant family history. His father had a myocardial infarction at the age of 53, and his paternal uncle died suddenly at the age of 35 for unknown reasons. His temperature is 37.1°C (98.8°F), the heart rate is 78/min, the blood pressure is 110/66 mm Hg, and the respiratory rate is 16/min. He has a tall, proportional body. There are no chest wall abnormalities. Lungs are clear to auscultation. His pulse is 2+ and regular in bilateral upper and lower extremities. His PMI is nondisplaced. Auscultation of his heart in the 5th intercostal space at the left midclavicular line reveals the following sound. Which of the following is the most likely outcome of this patient’s cardiac findings?
Q370
A 76-year-old woman with hypertension and coronary artery disease is brought to the emergency department after the sudden onset of right-sided weakness. Her pulse is 83/min and blood pressure is 156/90 mm Hg. Neurological examination shows right-sided facial drooping and complete paralysis of the right upper and lower extremities. Tongue position is normal and she is able to swallow liquids without difficulty. Knee and ankle deep tendon reflexes are exaggerated on the right. Sensation to vibration, position, and light touch is normal bilaterally. She is oriented to person, place, and time, and is able to speak normally. Occlusion of which of the following vessels is the most likely cause of this patient's current symptoms?
Cardiology US Medical PG Practice Questions and MCQs
Question 361: A 62-year-old man is brought to the emergency department with a sudden onset of severe chest pain, that he describes as tearing. The pain started 90 minutes back and is now referring to the upper back. There is a history of essential hypertension for the past 17 years. The patient has smoked 20–30 cigarettes daily for the past 27 years. Vital signs reveal: temperature 36.8°C (98.2°F), heart rate 105/min, and blood pressure 192/91 mm Hg in the right arm and 159/81 mm Hg in the left arm. Pulses are absent in the right leg and diminished in the left. ECG shows sinus tachycardia, and chest X-ray shows a widened mediastinum. Transthoracic echocardiography shows an intimal flap arising from the ascending aorta and extended to the left subclavian artery. Intravenous morphine sulfate is started. Which of the following is the best next step in the management of this patient condition?
A. Intravenous metoprolol (Correct Answer)
B. Intravenous hydralazine
C. Chest magnetic resonance imaging
D. Oral aspirin
E. D-dimer
Explanation: ***Intravenous metoprolol***
- This patient presents with an **acute aortic dissection** (type A given the involvement of the ascending aorta), which is a medical emergency requiring immediate management to reduce stress on the aorta and prevent rupture.
- **Beta-blockers** like metoprolol are the **first-line therapy** to rapidly **lower heart rate** and **blood pressure**, thereby reducing the shear stress on the aortic wall and limiting the propagation of the dissection.
*Intravenous hydralazine*
- Hydralazine is a direct **vasodilator** that can cause **reflex tachycardia**, which would increase the shear stress on the dissected aorta and worsen the condition.
- While it lowers blood pressure, it does not address the crucial need to reduce heart rate and myocardial contractility in aortic dissection.
*Chest magnetic resonance imaging*
- While MRI can provide detailed imaging of aortic dissection, the **diagnosis is already confirmed** by transthoracic echocardiography showing the intimal flap.
- Further diagnostic imaging is **not the priority**; immediate **medical stabilization** with beta-blockade to reduce aortic stress is the essential next step before considering definitive surgical management.
- MRI is also **time-consuming** and generally avoided in unstable patients requiring urgent intervention.
*Oral aspirin*
- Aspirin is an **antiplatelet agent** primarily used to prevent arterial thrombosis in conditions like myocardial infarction or stroke.
- It is **not indicated** for the acute management of aortic dissection and would not address the immediate hemodynamic goals of reducing heart rate and blood pressure.
*D-dimer*
- **D-dimer** is a marker of fibrin degradation products used as a screening tool for conditions like **pulmonary embolism** or deep vein thrombosis.
- While an elevated D-dimer can be seen in aortic dissection, it is a **non-specific test** and is not the best next step in immediate management, especially when the **diagnosis is already confirmed** by echocardiography.
Question 362: A 34-year-old G3P3 woman with a history of migraines presents with several weeks of headaches. The headaches are unlike her usual migraines and are worse in the morning. This morning she had an episode of emesis prompting her to seek medical care. She also has some right sided weakness which she believes is related to a new exercise routine. Her mother is a breast cancer survivor. Her medications include oral contraceptives and ibuprofen as needed, which has not helped her current headaches. She drinks 2-3 alcoholic drinks on the weekends and does not smoke. Physical examination is remarkable for bilateral papilledema. Motor exam is notable for upper and lower extremity strength 4/5 on the right and 5/5 on the left. Magnetic resonance venography demonstrates absent flow in the left venous sinuses. Which of the following predisposed this patient to her current condition?
A. Oral contraceptive use (Correct Answer)
B. Alcohol use
C. Family history
D. Ibuprofen use
E. History of migraines
Explanation: ***Oral contraceptive use***
- **Oral contraceptives** increase the risk of **venous thromboembolism**, including **cerebral venous thrombosis (CVT)**, which is strongly suggested by the patient's symptoms (headaches, papilledema, focal weakness) and the MRI finding of absent flow in the left venous sinuses.
- The combination of **oral contraceptive use** and **migraines with aura** can further elevate the risk of CVT, as both are independent risk factors.
*Alcohol use*
- Moderate alcohol consumption, as described (2-3 drinks on weekends), is generally **not considered a direct risk factor** for cerebral venous thrombosis.
- While chronic heavy alcohol use can indirectly affect coagulation, the patient's intake is not indicative of this.
*Family history*
- A family history of **breast cancer** (mother as a survivor) is not a direct predisposing factor for **cerebral venous thrombosis**.
- While some cancers can increase thrombotic risk, it is the active cancer and associated treatments, rather than a past family history, that are typically relevant.
*Ibuprofen use*
- **Ibuprofen**, a non-steroidal anti-inflammatory drug (NSAID), is not known to directly predispose to **cerebral venous thrombosis**.
- It works by inhibiting prostaglandin synthesis and is not associated with a prothrombotic state.
*History of migraines*
- A history of **migraines, particularly migraines with aura**, can be a **weak independent risk factor** for stroke, including some forms of thrombosis.
- However, in this specific case, the presence of oral contraceptive use is a much stronger and more direct predisposing factor for cerebral venous thrombosis, making it the primary predisposing condition.
Question 363: A 52-year-old man presents to the emergency department with sudden-onset dyspnea, tachypnea, and chest pain. He works as a long-haul truck driver, and he informs you that he recently returned to the west coast from a trip to Tennessee. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type 2, and mild intellectual disability. He currently smokes 2 packs of cigarettes/day, drinks a 6-pack of beer/day, and he endorses a past history of injection drug use but currently denies any illicit drug use. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 23/min. His physical examination shows minimal bibasilar rales, but otherwise clear lungs on auscultation, grade 2/6 holosystolic murmur, and a benign abdominal physical examination. A computed tomography angiography (CTA) demonstrates a segmental pulmonary embolism (PE). Which of the following is the most appropriate treatment plan for this patient?
A. Consult interventional radiologist (IR) for IVC filter placement
B. Initiate heparin
C. Tissue plasminogen activator (tPA)
D. Initiate heparin with a bridge to warfarin (Correct Answer)
E. Initiate warfarin anticoagulation
Explanation: ***Initiate heparin with a bridge to warfarin***
- This patient presents with a **segmental pulmonary embolism (PE)** and is hemodynamically stable (BP 126/74 mmHg, HR 87/min), making initial anticoagulation with **heparin** followed by a bridge to **warfarin** the most appropriate treatment.
- Heparin provides rapid anticoagulation, while warfarin is initiated concurrently and takes several days to reach therapeutic levels, requiring overlap until the **International Normalized Ratio (INR)** is within the therapeutic range (2.0-3.0).
*Consult interventional radiologist (IR) for IVC filter placement*
- **Inferior vena cava (IVC) filters** are typically reserved for patients with a **contraindication to anticoagulation** or those who experience **recurrent PE despite adequate anticoagulation**.
- This patient has no stated contraindications to anticoagulation and has not failed initial therapy, so an IVC filter is not indicated at this time.
*Initiate heparin*
- While initiating **heparin** is the correct first step, it is incomplete as a long-term treatment strategy for PE.
- Patients with PE require **long-term anticoagulation** (typically 3-6 months or longer), for which warfarin or novel oral anticoagulants (NOACs) are used, following an initial period of rapid-acting anticoagulation.
*Tissue plasminogen activator (tPA)*
- **Thrombolytic therapy with tPA** is indicated for patients with **massive PE** who are **hemodynamically unstable** (e.g., hypotension, shock).
- This patient is hemodynamically stable, and his PE is segmental, so thrombolysis carries a higher risk of bleeding complications than benefits in this case.
*Initiate warfarin anticoagulation*
- **Warfarin** has a slow onset of action (3-5 days to achieve therapeutic INR) and therefore should not be used as monotherapy for initial management of acute PE.
- Initial management requires a **rapid-acting anticoagulant** like heparin or low molecular weight heparin (LMWH) to prevent further clot propagation and embolization.
Question 364: A 65-year-old male engineer presents to the office with shortness of breath on exertion and a dry cough that he has had for about a year. He is a heavy smoker with a 25-pack-years history. His vitals include: heart rate 95/min, respiratory rate 26/min, and blood pressure 110/75 mm Hg. On examination, he presents with nail clubbing and bilateral and persistent crackling rales. The chest radiograph shows basal reticulonodular symmetric images, with decreased lung fields. The pulmonary function tests show the following: diffusing capacity of the lungs for carbon monoxide (DLCO) is 43% and reference SaO2 is 94% and 72%, at rest and with exercise, respectively. What is the most likely diagnosis?
A. Chronic hypersensitivity pneumonitis
B. Pulmonary Langerhans cell histiocytosis
C. Pleuropulmonary fibroelastosis
D. Asbestosis
E. Idiopathic pulmonary fibrosis (Correct Answer)
Explanation: ***Idiopathic pulmonary fibrosis***
- This patient's presentation with **progressive dyspnea**, **dry cough**, **clubbing**, and **basal crackles (rales)**, combined with restrictive lung physiology (low **DLCO**) and **basal reticulonodular infiltrates** on CXR, is highly characteristic of **idiopathic pulmonary fibrosis**. The marked **desaturation with exercise** further supports this diagnosis.
- While smoking is a risk factor, the pattern of lung disease is consistent with IPF, a chronic, progressive, fibrosing interstitial pneumonia of unknown cause.
*Chronic hypersensitivity pneumonitis*
- This condition is caused by **chronic exposure to inhaled antigens** and typically presents with symptoms that link back to the exposure, potentially resolving with avoidance.
- While it can cause interstitial lung disease, the absence of an identifiable antigen exposure and the typical fibrotic pattern with subpleural honeycombing would make IPF more likely.
*Pulmonary Langerhans cells histiocytosis*
- This disease is strongly associated with **smoking** but typically presents with **cysts and nodules** predominantly in the **upper and middle lung fields** on imaging.
- The patient's **basal reticulonodular pattern** with decreased lung fields on CXR, rather than cysts, makes this diagnosis less likely.
*Pleuropulmonary fibroelastosis*
- This is a rare interstitial lung disease characterized by **fibrosis predominantly affecting the upper lobes** and pleura.
- The patient's **basal predominant findings** on chest radiograph and crackles make this diagnosis less consistent.
*Asbestosis*
- Although the patient's occupation as an engineer could suggest **asbestos exposure**, the description lacks specific features like **pleural plaques** or calcifications.
- While asbestosis can cause diffuse interstitial fibrosis and similar symptoms, the clinical and radiological picture, especially the extent of **DLCO reduction** for the given findings, more strongly points to IPF.
Question 365: A 62-year-old man presents to his primary care physician because he is unhappy about his inability to tan this summer. He has been going to the beach with his family and friends, but he has remained pale. He has no other complaints except that he has been getting tired more easily, which he attributes to normal aging. Based on clinical suspicion a panel of tests are performed with the following results:
Hemoglobin: 11 g/dL
Leukocyte count: 5,370/mm^3
Platelet count: 168,000/mm^3
Mean corpuscular volume: 95 µm^3
Haptoglobin level: Decreased
Reticulocytes: 3%
Peripheral blood smear is also obtained and shown in the figure provided. Which of the following patient characteristics is consistent with the most likely cause of this patient's disease?
A. Consumption of fava beans
B. Aortic valve replacement (Correct Answer)
C. Inheritance of cytoskeletal defect
D. Red urine in the morning
E. Infection of red blood cells
Explanation: ***Aortic valve replacement***
- The patient's symptoms (fatigue, pale skin suggestive of anemia) combined with laboratory findings (anemia, decreased haptoglobin, elevated reticulocytes indicative of hemolysis) and the peripheral smear showing **schistocytes** (fragmented red blood cells) strongly point towards **microangiopathic hemolytic anemia**.
- **Mechanical heart valves**, particularly prosthetic aortic valves, can cause turbulent blood flow and shear stress on red blood cells, leading to their fragmentation and subsequent hemolytic anemia.
*Consumption of fava beans*
- This can trigger **hemolytic anemia** in individuals with **glucose-6-phosphate dehydrogenase (G6PD) deficiency**.
- While it causes hemolysis, G6PD deficiency typically presents with **Heinz bodies** and **bite cells** rather than characteristically producing schistocytes from mechanical fragmentation.
*Inheritance of cytoskeletal defect*
- A defect in red blood cell cytoskeletal proteins (e.g., in **hereditary spherocytosis** or **hereditary elliptocytosis**) leads to abnormal red blood cell shapes and increased fragility.
- While these conditions cause hemolytic anemia, they primarily result in **spherocytes** or **elliptocytes**, not schistocytes, and would typically present earlier in life.
*Red urine in the morning*
- This is a classic symptom of **paroxysmal nocturnal hemoglobinuria (PNH)**, a rare acquired hemolytic anemia characterized by a defect in GPI-anchored proteins on red blood cell surfaces.
- PNH involves intravascular hemolysis but does not typically manifest with the widespread schistocytes seen in microangiopathic hemolytic anemia.
*Infection of red blood cells*
- Infections like **malaria** can cause hemolytic anemia by directly invading and destroying red blood cells.
- However, the peripheral smear would show **parasites within red blood cells**, not the fragmented schistocytes indicative of mechanical destruction.
Question 366: A 51-year-old woman is brought into the emergency department following a motor vehicle accident. She is unconscious and was intubated in the field. Past medical history is unknown. Upon arrival, she is hypotensive and tachycardic. Her temperature is 37.2°C (99.1°F), the pulse is 110/min, the respiratory rate is 22/min, and the blood pressure is 85/60 mm Hg. There is no evidence of head trauma, she withdraws to pain and her pupils are 2mm and reactive to light. Her heart has a regular rhythm without any murmurs or rubs and her lungs are clear to auscultation. Her abdomen is firm and distended with decreased bowel sounds. Her extremities are cool and clammy with weak, thready pulses. There is no peripheral edema. Of the following, what is the likely cause of her presentation?
A. Septic shock
B. Neurogenic shock
C. Obstructive shock
D. Hypovolemic shock (Correct Answer)
E. Cardiogenic shock
Explanation: ***Hypovolemic shock***
- The patient's presentation with ***hypotension*** (BP 85/60 mm Hg), ***tachycardia*** (pulse 110/min), ***cool and clammy extremities***, ***weak peripheral pulses***, and a ***firm, distended abdomen*** after a motor vehicle accident strongly suggests internal hemorrhage leading to hypovolemic shock.
- The ***firm and distended abdomen*** is a key indicator of potential intra-abdominal bleeding, significantly contributing to the loss of intravascular volume.
*Septic shock*
- Septic shock is characterized by signs of infection along with organ dysfunction and circulatory compromise, often presenting with **fever** or **hypothermia**, and sometimes **warm extremities** initially due to vasodilation. This patient's temperature is normal, and extremities are cool.
- While hypotension and tachycardia are present, the absence of clear signs of infection and the presence of a firm, distended abdomen make hypovolemia a more immediate concern following trauma.
*Neurogenic shock*
- Neurogenic shock typically follows severe spinal cord injury above T6, leading to a loss of sympathetic tone. This results in **hypotension with bradycardia** and **warm, dry skin** due to widespread vasodilation.
- This patient is tachycardic and has cool, clammy extremities, which contradicts the classic presentation of neurogenic shock.
*Obstructive shock*
- Obstructive shock occurs due to a physical obstruction to central circulation, such as **tension pneumothorax**, **cardiac tamponade**, or **pulmonary embolism**.
- There is no mention of absent breath sounds, jugular venous distention, muffled heart sounds, or other specific signs pointing to an obstructive cause. Lungs are clear to auscultation and heart rhythm is regular.
*Cardiogenic shock*
- Cardiogenic shock results from primary cardiac dysfunction, often presenting with signs of **heart failure**, such as **pulmonary edema** (rales), **jugular venous distention**, gallop rhythms, or new murmurs.
- The patient has clear lungs, a regular heart rhythm, and no murmurs, which makes primary cardiac dysfunction less likely as the immediate cause of shock in this trauma setting.
Question 367: Two weeks after undergoing an emergency cardiac catheterization for unstable angina pectoris, a 65-year-old man has decreased urinary output. He takes naproxen for osteoarthritis and was started on aspirin, clopidogrel, and metoprolol after the coronary intervention. His temperature is 38.1°C (100.5°F), pulse is 96/min, and blood pressure is 128/88 mm Hg. Examination shows mottled, reticulated purplish discoloration of the feet and ischemic changes on the right big toe. His leukocyte count is 16,500/mm3 with 56% segmented neutrophils, 12% eosinophils, 30% lymphocytes, and 2% monocytes. His serum creatinine concentration is 4.5 mg/dL. A photomicrograph of a kidney biopsy specimen is shown. Which of the following is the most likely cause of this patient's presentation?
A. Contrast-induced nephropathy
B. Renal papillary necrosis
C. Cholesterol embolization (Correct Answer)
D. Allergic interstitial nephritis
E. Eosinophilic granulomatosis with polyangiitis
Explanation: ***Cholesterol embolization***
- The patient's history of recent **cardiac catheterization**, elevated creatinine, **mottled feet (livedo reticularis)**, and **ischemic changes in the big toe (blue toe syndrome)** are classic signs of cholesterol embolization.
- The biopsy showing cholesterol clefts along with eosinophilia and elevated WBC count further supports this diagnosis.
*Contrast-induced nephropathy*
- This typically presents within **24-48 hours** of contrast exposure, not two weeks later, and usually lacks systemic embolic phenomena.
- While it causes acute kidney injury, it does not explain the **cutaneous findings** like livedo reticularis or blue toe syndrome.
*Renal papillary necrosis*
- Often associated with **analgesic nephropathy (NSAID use)**, sickle cell disease, diabetes, or obstruction, but the clinical picture here is dominated by widespread embolic signs.
- While naproxen use could be a risk factor, it typically presents with **flank pain, hematuria**, and sometimes sloughed papillae in the urine, none of which are described.
*Allergic interstitial nephritis*
- Can be caused by drugs like **NSAIDs, penicillins, or sulfonamides**, manifesting with fever, rash, and eosinophilia.
- However, it does not explain the prominent **mottled feet and blue toe syndrome** caused by microemboli.
*Eosinophilic granulomatosis with polyangiitis*
- This condition is characterized by **severe asthma, eosinophilia**, and systemic vasculitis affecting various organs, including the kidneys.
- While the patient has eosinophilia, the acute onset following a procedure and the specific embolic skin findings are more suggestive of cholesterol embolization than a primary vasculitic disorder.
Question 368: A 25-year-old previously healthy woman is admitted to the hospital with progressively worsening shortness of breath. She reports a mild fever. Her vital signs at the admission are as follows: blood pressure 100/70 mm Hg, heart rate 111/min, respiratory rate 20/min, and temperature 38.1℃ (100.6℉); blood saturation on room air is 90%. Examination reveals a bilateral decrease of vesicular breath sounds and rales in the lower lobes. Plain chest radiograph demonstrates bilateral opacification of the lower lobes. Despite appropriate treatment, her respiratory status worsens. The patient is transferred to the intensive care unit and put on mechanical ventilation. Adjustment of which of the following ventilator settings will only affect the patient’s oxygenation?
A. Tidal volume and respiratory rate
B. FiO2 and PEEP (Correct Answer)
C. Respiratory rate and PEEP
D. Tidal volume and FiO2
E. FiO2 and respiratory rate
Explanation: ***FiO2 and PEEP***
- **FiO2 (fraction of inspired oxygen)** directly controls the oxygen concentration delivered to the patient, thus solely impacting **oxygenation**.
- **PEEP (positive end-expiratory pressure)** prevents alveolar collapse and recruits collapsed alveoli, improving the **functional residual capacity** and thus **oxygenation** without significantly altering CO2 removal (ventilation).
*Tidal volume and respiratory rate*
- **Tidal volume (Vt)** directly impacts the amount of air moved with each breath, primarily affecting **ventilation** (CO2 removal).
- **Respiratory rate (RR)** also directly determines the total minute ventilation, thus influencing **ventilation** more than oxygenation.
*Respiratory rate and PEEP*
- As mentioned, **respiratory rate** significantly affects **ventilation** by altering minute ventilation (Vt x RR).
- While **PEEP** primarily affects oxygenation, the combination with respiratory rate means it's not exclusively targeting oxygenation.
*Tidal volume and FiO2*
- **Tidal volume** is a key determinant of **ventilation** (CO2 removal), not solely oxygenation.
- **FiO2** does affect oxygenation, but its combination with tidal volume makes this option incorrect for *only* affecting oxygenation.
*FiO2 and respiratory rate*
- **FiO2** directly impacts **oxygenation**.
- **Respiratory rate** primarily affects **ventilation** (CO2 removal), thereby influencing carbonic acid levels and pH.
Question 369: A healthy 20-year-old African American man presents to the clinic for pre-participation sports physical for college football. He has no health complaints at this time. He has no recent history of illness or injury. He denies chest pain and palpitations. He reports no prior syncopal episodes. He had surgery 2 years ago for appendicitis. His mother is healthy and has an insignificant family history. His father had a myocardial infarction at the age of 53, and his paternal uncle died suddenly at the age of 35 for unknown reasons. His temperature is 37.1°C (98.8°F), the heart rate is 78/min, the blood pressure is 110/66 mm Hg, and the respiratory rate is 16/min. He has a tall, proportional body. There are no chest wall abnormalities. Lungs are clear to auscultation. His pulse is 2+ and regular in bilateral upper and lower extremities. His PMI is nondisplaced. Auscultation of his heart in the 5th intercostal space at the left midclavicular line reveals the following sound. Which of the following is the most likely outcome of this patient’s cardiac findings?
A. Infective endocarditis
B. Asymptomatic
C. Systolic heart failure
D. Sudden cardiac death (Correct Answer)
E. Atrial fibrillation
Explanation: ***Sudden cardiac death***
- This patient has **significant family history**: paternal uncle with sudden death at age 35 and father with early MI at 53, strongly suggesting **hypertrophic cardiomyopathy (HCM)** with autosomal dominant inheritance.
- HCM is the **most common cause of sudden cardiac death in young athletes**, particularly in African Americans who have higher prevalence of HCM.
- The auscultation finding (systolic murmur that increases with Valsalva maneuver) is consistent with **left ventricular outflow tract obstruction** seen in HCM.
- Despite being currently asymptomatic, the **most concerning outcome** in an athlete with suspected HCM is **sudden cardiac death** during exertion, which occurs due to ventricular arrhythmias.
- This patient requires further workup with **echocardiography and ECG** and should be restricted from competitive sports until HCM is ruled out.
*Asymptomatic*
- While the patient is currently asymptomatic, this describes his **present state**, not a future **outcome** or clinical consequence.
- The question asks for the "most likely outcome" of his cardiac findings, not his current symptom status.
*Infective endocarditis*
- This patient has no risk factors for endocarditis (no prosthetic valves, no IV drug use, no recent procedures).
- While HCM patients have increased endocarditis risk due to structural abnormalities, sudden cardiac death remains the **most feared and likely adverse outcome** in young athletes.
*Atrial fibrillation*
- While atrial fibrillation can occur in HCM patients (typically later in disease course), it is **not the most concerning outcome** in a young athlete.
- The patient has a **regular pulse at 78/min**, and sudden cardiac death from ventricular arrhythmias is a more immediate concern.
*Systolic heart failure*
- Systolic heart failure can develop in **end-stage HCM** (burned-out phase), but this occurs in older patients after years of disease.
- In a **young athlete with HCM**, sudden cardiac death from ventricular arrhythmias during exertion is the **most immediate and likely adverse outcome**.
Question 370: A 76-year-old woman with hypertension and coronary artery disease is brought to the emergency department after the sudden onset of right-sided weakness. Her pulse is 83/min and blood pressure is 156/90 mm Hg. Neurological examination shows right-sided facial drooping and complete paralysis of the right upper and lower extremities. Tongue position is normal and she is able to swallow liquids without difficulty. Knee and ankle deep tendon reflexes are exaggerated on the right. Sensation to vibration, position, and light touch is normal bilaterally. She is oriented to person, place, and time, and is able to speak normally. Occlusion of which of the following vessels is the most likely cause of this patient's current symptoms?
A. Ipsilateral anterior cerebral artery
B. Contralateral middle cerebral artery
C. Anterior spinal artery
D. Contralateral lenticulostriate artery (Correct Answer)
E. Ipsilateral posterior inferior cerebellar artery
Explanation: ***Contralateral lenticulostriate artery***
- The patient presents with **pure motor hemiparesis** affecting the face, arm, and leg equally on the right side, with **no sensory deficits, aphasia, or cognitive impairment**.
- This clinical pattern is classic for a **lacunar stroke** affecting the **internal capsule**, which is supplied by the **lenticulostriate arteries** (branches of the middle cerebral artery).
- The internal capsule contains tightly packed corticospinal and corticobulbar fibers; a small infarct here causes complete contralateral motor deficits without cortical signs.
- The **absence of cortical findings** (normal speech, cognition, and sensation) distinguishes this from cortical MCA stroke.
*Contralateral middle cerebral artery*
- A **cortical MCA stroke** would typically present with **cortical signs** such as aphasia (if left hemisphere), neglect (if right hemisphere), sensory loss, and visual field defects.
- MCA strokes usually show **arm and face > leg** weakness (the leg area is supplied by ACA).
- This patient's **pure motor syndrome** without cortical signs points to a subcortical lesion, not cortical MCA occlusion.
*Ipsilateral anterior cerebral artery*
- First, the lateralization is incorrect - symptoms are right-sided, indicating left hemisphere pathology, so it would be **contralateral** ACA.
- ACA occlusion causes weakness predominantly in the **contralateral leg > arm**, with relative sparing of the face.
- This patient has equal involvement of face, arm, and leg, which is inconsistent with ACA territory.
*Anterior spinal artery*
- The **anterior spinal artery** supplies the anterior two-thirds of the spinal cord, including the corticospinal tracts and anterior horn cells.
- Occlusion causes **bilateral** motor weakness below the lesion level and bilateral loss of pain/temperature sensation.
- It does not cause **unilateral facial weakness** or the distribution of deficits seen in this patient.
*Ipsilateral posterior inferior cerebellar artery*
- Again, lateralization is incorrect - symptoms would be from **contralateral** PICA for motor findings, but PICA supplies the lateral medulla and inferior cerebellum.
- PICA occlusion causes **lateral medullary syndrome (Wallenberg syndrome)**: ataxia, vertigo, dysphagia, dysarthria, Horner syndrome, and contralateral pain/temperature loss.
- The patient's **pure motor hemiparesis** without cerebellar or brainstem signs is incompatible with PICA occlusion.
