A 75-year-old man comes to the emergency department because of fatigue and black sticky stools during the past 3 days. He also complains of nausea and has had a 2-kg (4.4-lb) weight loss over the past month. He has a history of polycystic kidney disease, hypertension, and hyperlipidemia. He does not smoke or drink alcohol. Current medications include hydrochlorothiazide, furosemide, valsartan, and atorvastatin. He is thin and appears tired. His temperature is 37.0°C (98.6°F), pulse is 75/min, and blood pressure is 110/65 mm Hg. Examination shows conjunctival pallor and numerous excoriations on the extensor surfaces of his upper extremities. Abdominal examination shows no abnormalities. There is a flapping tremor when both wrists are flexed. Laboratory studies show:
Hemoglobin 8.5 g/dL
Platelets 109,000/mm3
Mean corpuscular volume 81 μm3
Prothrombin time 11 sec
Partial thromboplastin time 34 sec
Serum
Creatinine 6.1 mg/dL
Which of the following is the most likely underlying cause of this patient's current condition?
Q532
An 8-year-old boy is brought to the physician by his father because of abnormal movements of his limbs. For the past four days, he has had uncontrolled jerking movements of his arms and legs and has been dropping cups and toys. His symptoms are worse when he is excited and improve while he is asleep. During the same time period, he has become increasingly irritable and tearful. He had a sore throat 6 weeks ago that resolved without treatment. His temperature is 37.3°C (99.2°F). Examination shows occasional grimacing with involuntary jerking movements of his limbs. Muscle strength and tone are decreased in all extremities. When he grips the physician's index and middle fingers with his hands, his grip increases and decreases continuously. This patient is at increased risk for which of the following complications?
Q533
A patient presents to his primary care physician with complaints of regular headaches and upper abdominal pain. On physical examination, his spleen and liver seem enlarged, and his face is plethoric. Gastroendoscopy reveals several gastric ulcers ranging from 3–5 mm in greatest dimension. A bone marrow aspirate shows hypercellularity with fibrosis and serum erythropoietin is low. The patient is informed about a new treatment with ruxolitinib for the main cause of his symptoms. Which of the conditions below can develop due to the same mutation that is causing this patient's symptoms?
Q534
A 70-year-old male comes to the emergency department complaining of severe back pain. The pain started 20 minutes ago when he was sitting and watching TV. He describes the pain as intense, epigastric, and radiating to his back. His vitals on presentation to the emergency department are blood pressure is 150/75 mmHg, pulse is 110/min, and respirations are 24/min with an oxygen saturation of 98% on room air. His body mass index is 35 kg/m^2 and he appears pale and in visible pain. On abdominal exam, his abdomen is tender and a pulsatile mass is felt in the midline during deep palpation. His past medical history includes diabetes, hypertension well-controlled on medications, and a history of benign prostatic hyperplasia. His social history is notable for consuming 2-3 beers per night and a smoking history of ½ pack per day. Which of the following is considered the greatest risk factor for this patient's condition?
Q535
A 32-year-old woman presents with new left-arm pain. She was previously well but for 2 months has had episodes of low-grade fever, night sweats, and dizziness. She works as a stock assistant and has noticed left arm pain when she stocks shelves. She is taking a multivitamin but no other medications. On physical examination, her blood pressure is 126/72 in her right arm, but it cannot be measured in her left arm. The left radial pulse is not detectable. There is a bruit over the left subclavian area. Femoral and pedal pulses are normal and no abdominal bruits are heard. The left hand is cool but has no other evidence of ischemia. Which of the following is the most likely etiology of this patient’s condition?
Q536
A 32-year-old woman comes to the clinic for a routine evaluation. This is her first time visiting this office. Her medical history is significant for cystic medial necrosis of the aorta. Her vital signs include: heart rate 85/min, respiratory rate 15/min, temperature 36.0°C (96.8°F), and blood pressure 110/80 mm Hg. Physical examination shows she is thin and tall with abnormally long extremities and spider-like fingers. Which of the following disorders does the patient most likely have?
Q537
A 42-year-old man presents to his physician with dark urine and intermittent flank pain. He has no significant past medical history and generally is healthy. His temperature is 97.5°F (36.4°C), blood pressure is 182/112 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical examination is significant for bilateral palpable flank masses and discomfort to percussion of the costovertebral angle. Urinalysis is positive for red blood cells without any bacteria or nitrites. Which of the following diagnostic modalities should be used to screen members of this patient's family to assess if they are affected by the same condition?
Q538
A 60-year-old man presents to the emergency department with pleuritic chest pain. He recently returned from a vacation in Germany and noticed he felt short of breath and had chest pain the following morning. The patient is generally healthy but did have surgery on his ankle 3 weeks ago and has been less ambulatory. His temperature is 99.0°F (37.2°C), blood pressure is 137/88 mm Hg, pulse is 120/min, respirations are 22/min, and oxygen saturation is 96% on room air. Physical exam is notable for a warm and swollen lower extremity. The physician has high clinical suspicion for pulmonary embolism given the patient's risk factors and presentation. Which of the following findings would warrant further workup with a CT angiogram?
Q539
A 54-year-old man comes to the emergency department because of severe pain in his right leg that began suddenly 3 hours ago. He has had repeated cramping in his right calf while walking for the past 4 months, but it has never been this severe. He has type 2 diabetes mellitus, hypercholesterolemia, and hypertension. Current medications include insulin, enalapril, aspirin, and simvastatin. He has smoked one pack of cigarettes daily for 33 years. He does not drink alcohol. His pulse is 103/min and blood pressure is 136/84 mm Hg. Femoral pulses are palpable bilaterally. The popliteal and pedal pulses are absent on the right. Laboratory studies show:
Hemoglobin 16.1 g/dL
Serum
Urea nitrogen 14 mg/dL
Glucose 166 mg/dL
Creatinine 1.5 mg/dL
A CT angiogram of the right lower extremity is ordered. Which of the following is the most appropriate next step in management?
Q540
A previously healthy 19-year-old man is brought to the emergency department by his girlfriend after briefly losing consciousness. He passed out while moving furniture into her apartment. She said that he was unresponsive for a minute but regained consciousness and was not confused. The patient did not have any chest pain, palpitations, or difficulty breathing before or after the episode. He has had episodes of dizziness when exercising at the gym. His blood pressure is 125/75 mm Hg while supine and 120/70 mm Hg while standing. Pulse is 70/min while supine and 75/min while standing. On examination, there is a grade 3/6 systolic murmur at the left lower sternal border and a systolic murmur at the apex, both of which disappear with passive leg elevation. Which of the following is the most likely cause?
Cardiology US Medical PG Practice Questions and MCQs
Question 531: A 75-year-old man comes to the emergency department because of fatigue and black sticky stools during the past 3 days. He also complains of nausea and has had a 2-kg (4.4-lb) weight loss over the past month. He has a history of polycystic kidney disease, hypertension, and hyperlipidemia. He does not smoke or drink alcohol. Current medications include hydrochlorothiazide, furosemide, valsartan, and atorvastatin. He is thin and appears tired. His temperature is 37.0°C (98.6°F), pulse is 75/min, and blood pressure is 110/65 mm Hg. Examination shows conjunctival pallor and numerous excoriations on the extensor surfaces of his upper extremities. Abdominal examination shows no abnormalities. There is a flapping tremor when both wrists are flexed. Laboratory studies show:
Hemoglobin 8.5 g/dL
Platelets 109,000/mm3
Mean corpuscular volume 81 μm3
Prothrombin time 11 sec
Partial thromboplastin time 34 sec
Serum
Creatinine 6.1 mg/dL
Which of the following is the most likely underlying cause of this patient's current condition?
A. Acquired factor VII deficiency
B. Decreased levels of von Willebrand factor
C. Dysfunctional platelet aggregation (Correct Answer)
D. Inherited antithrombin deficiency
E. Impaired production of thrombopoietin
Explanation: ***Dysfunctional platelet aggregation***
- The patient presents with **pruritus (excoriations)**, **fatigue**, and **black, tarry stools (melena)**, indicating **gastrointestinal bleeding**. His lab findings show **anemia** (hemoglobin 8.5 mg/dL) and **thrombocytopenia** (platelets 109,000/mm³).
- The significantly elevated **creatinine (6.1 mg/dL)** points to **severe kidney failure**, which commonly leads to uremia. In **uremia**, circulating toxins impair **platelet function**, specifically **platelet aggregation and adhesion**, even with a sufficient platelet count (though this patient also has thrombocytopenia). This **dysfunctional platelet aggregation** is the most likely cause of increased bleeding tendency in a patient with end-stage renal disease.
*Acquired factor VII deficiency*
- **Factor VII deficiency** would primarily manifest as a prolonged **prothrombin time (PT)**, as factor VII is part of the extrinsic coagulation pathway.
- The patient's PT is 11 seconds, which is within the normal range, making **acquired factor VII deficiency** unlikely.
*Decreased levels of von Willebrand factor*
- **Decreased von Willebrand factor** (vWF) would lead to impaired primary hemostasis, prolonged bleeding time, and sometimes a slightly prolonged activated partial thromboplastin time (aPTT) if factor VIII levels are also affected (vWF protects factor VIII).
- While bleeding is present, the primary issue in severe renal failure leading to bleeding is typically **platelet dysfunction**, not solely vWF deficiency.
*Inherited antithrombin deficiency*
- **Antithrombin deficiency** is a **thrombophilic disorder**, meaning it increases the risk of **thrombosis ( clot formation)**, not bleeding.
- This condition would lead to symptoms like deep vein thrombosis or pulmonary embolism, which are not present in this clinical picture.
*Impaired production of thrombopoietin*
- **Thrombopoietin** is primarily produced by the **liver** and is the main regulator of **platelet production**. Impaired production would lead to **thrombocytopenia**.
- While the patient has thrombocytopenia, the more pressing issue causing bleeding in renal failure is the **qualitative platelet defect (dysfunction)**, not merely a lack of platelet numbers, and the kidney itself is not the primary site of thrombopoietin production impacting overall levels significantly.
Question 532: An 8-year-old boy is brought to the physician by his father because of abnormal movements of his limbs. For the past four days, he has had uncontrolled jerking movements of his arms and legs and has been dropping cups and toys. His symptoms are worse when he is excited and improve while he is asleep. During the same time period, he has become increasingly irritable and tearful. He had a sore throat 6 weeks ago that resolved without treatment. His temperature is 37.3°C (99.2°F). Examination shows occasional grimacing with involuntary jerking movements of his limbs. Muscle strength and tone are decreased in all extremities. When he grips the physician's index and middle fingers with his hands, his grip increases and decreases continuously. This patient is at increased risk for which of the following complications?
A. Extraneural metastasis
B. Early-onset dementia
C. Diabetes mellitus
D. Attention deficit hyperactivity disorder
E. Mitral regurgitation (Correct Answer)
Explanation: ***Mitral regurgitation***
- This patient has **Sydenham chorea**, a major manifestation of **acute rheumatic fever (ARF)** following group A streptococcal pharyngitis 6 weeks ago
- Classic features present: choreiform movements, emotional lability, milkmaid's grip (motor impersistence), hypotonia, and symptoms that worsen with stress and improve with sleep
- **Rheumatic heart disease** develops in 50-60% of ARF patients, with the **mitral valve** being the most commonly affected (70-80% of cases)
- Chronic valvular damage occurs due to molecular mimicry between streptococcal M protein and cardiac myosin, leading to autoimmune-mediated inflammation
- **Mitral regurgitation** is the most common valvular lesion in acute ARF, and patients require long-term antibiotic prophylaxis to prevent recurrent episodes and progressive cardiac damage
*Extraneural metastasis*
- This refers to cancer spreading outside the nervous system and is completely unrelated to the clinical presentation
- The patient has a post-infectious autoimmune condition (ARF), not a malignancy
- Chorea in children with cancer would suggest paraneoplastic syndrome or CNS involvement, not metastasis
*Early-onset dementia*
- Sydenham chorea causes transient behavioral and cognitive changes but does not lead to progressive cognitive decline or dementia
- Cognitive symptoms typically resolve within months, though some emotional/behavioral issues may persist
- Dementia in children would suggest neurodegenerative disorders (e.g., leukodystrophies, storage diseases), not post-streptococcal sequelae
*Diabetes mellitus*
- There is no pathophysiologic link between acute rheumatic fever and diabetes mellitus
- This metabolic disorder involves insulin deficiency or resistance and is unrelated to post-streptococcal autoimmune phenomena
- Completely inappropriate complication for this clinical scenario
*Attention deficit hyperactivity disorder*
- While Sydenham chorea can cause transient hyperactivity, emotional lability, and attention difficulties, these are manifestations of the acute illness
- True ADHD is a chronic neurodevelopmental disorder with different pathophysiology and diagnostic criteria
- Behavioral symptoms in Sydenham chorea typically improve as the chorea resolves (usually within 3-6 months), unlike the persistent pattern required for ADHD diagnosis
Question 533: A patient presents to his primary care physician with complaints of regular headaches and upper abdominal pain. On physical examination, his spleen and liver seem enlarged, and his face is plethoric. Gastroendoscopy reveals several gastric ulcers ranging from 3–5 mm in greatest dimension. A bone marrow aspirate shows hypercellularity with fibrosis and serum erythropoietin is low. The patient is informed about a new treatment with ruxolitinib for the main cause of his symptoms. Which of the conditions below can develop due to the same mutation that is causing this patient's symptoms?
A. Acute monocytic leukemia
B. Essential thrombocythemia (Correct Answer)
C. Mantle cell lymphoma
D. Chronic myelogenous leukemia
E. Burkitt's lymphoma
Explanation: ***Essential thrombocythemia***
- The patient's symptoms (headaches, abdominal pain, splenomegaly, hepatomegaly, plethora, gastric ulcers, hypercellular bone marrow with fibrosis, low erythropoietin) are classic for **Polycythemia Vera (PV)**, which is almost always caused by a **JAK2 V617F mutation**.
- **Essential thrombocythemia (ET)** is another **BCR-ABL1 negative myeloproliferative neoplasm** that shares the same **JAK2 V617F mutation** in about 50-60% of cases, making it a condition that can arise from the same genetic abnormality.
*Acute monocytic leukemia*
- This is a type of **acute myeloid leukemia**, characterized by a proliferation of **monoblasts** and **monocytes**.
- It is not typically caused by the **JAK2 V617F mutation**; rather, it often involves mutations in genes like *NPM1*, *FLT3*, or *RUNX1*.
*Mantle cell lymphoma*
- This is a **B-cell non-Hodgkin lymphoma** characterized by the **t(11;14)(q13;q32) translocation**, leading to overexpression of **cyclin D1**.
- It is completely unrelated to the **JAK2 V617F mutation** and does not present with features of a myeloproliferative neoplasm.
*Chronic myelogenous leukemia*
- This is a **myeloproliferative neoplasm** characterized by the **BCR-ABL1 fusion gene** (Philadelphia chromosome **t(9;22)**).
- While it is a myeloproliferative neoplasm, it is distinct from Polycythemia Vera and is not caused by the JAK2 V617F mutation.
*Burkitt's lymphoma*
- This is an aggressive **B-cell non-Hodgkin lymphoma** strongly associated with translocations of the **MYC gene**, most commonly **t(8;14)**.
- It has no connection to the **JAK2 V617F mutation** or myeloproliferative disorders.
Question 534: A 70-year-old male comes to the emergency department complaining of severe back pain. The pain started 20 minutes ago when he was sitting and watching TV. He describes the pain as intense, epigastric, and radiating to his back. His vitals on presentation to the emergency department are blood pressure is 150/75 mmHg, pulse is 110/min, and respirations are 24/min with an oxygen saturation of 98% on room air. His body mass index is 35 kg/m^2 and he appears pale and in visible pain. On abdominal exam, his abdomen is tender and a pulsatile mass is felt in the midline during deep palpation. His past medical history includes diabetes, hypertension well-controlled on medications, and a history of benign prostatic hyperplasia. His social history is notable for consuming 2-3 beers per night and a smoking history of ½ pack per day. Which of the following is considered the greatest risk factor for this patient's condition?
A. Smoking (Correct Answer)
B. Benign prostatic hyperplasia
C. Obesity
D. Diabetes
E. Alcohol consumption
Explanation: ***Smoking***
- **Smoking** is the single most significant modifiable risk factor for the development and expansion of **abdominal aortic aneurysms (AAAs)** due to its detrimental effects on arterial wall integrity.
- Nicotine and other toxins in smoke contribute to **inflammation**, **oxidative stress**, and **elastin degradation** within the aortic wall.
*Benign prostatic hyperplasia*
- **Benign prostatic hyperplasia (BPH)** is not a risk factor for abdominal aortic aneurysm formation or rupture.
- It is a condition of the prostate gland causing urinary symptoms and has no pathophysiological link to aortic disease.
*Obesity*
- While **obesity** is a risk factor for many cardiovascular diseases, its association with **abdominal aortic aneurysms (AAAs)** is less direct than other factors, often mediated through related conditions like hypertension.
- Some studies suggest a **protective effect** or no significant association between obesity and AAA, although this remains an area of ongoing research.
*Diabetes*
- **Diabetes** is generally considered to have a **paradoxical or even protective effect** against the development of **abdominal aortic aneurysms (AAAs)**, although it significantly increases the risk of other vascular complications.
- The exact mechanism is not fully understood but may involve changes in the aortic wall's structural properties or reduced inflammation in diabetic patients with AAAs.
*Alcohol consumption*
- **Moderate alcohol consumption** has not been consistently linked to an increased risk of **abdominal aortic aneurysms (AAAs)**.
- **Excessive alcohol consumption** can contribute to overall cardiovascular disease risk, but it is not identified as a primary or strong independent risk factor for AAA formation or rupture.
Question 535: A 32-year-old woman presents with new left-arm pain. She was previously well but for 2 months has had episodes of low-grade fever, night sweats, and dizziness. She works as a stock assistant and has noticed left arm pain when she stocks shelves. She is taking a multivitamin but no other medications. On physical examination, her blood pressure is 126/72 in her right arm, but it cannot be measured in her left arm. The left radial pulse is not detectable. There is a bruit over the left subclavian area. Femoral and pedal pulses are normal and no abdominal bruits are heard. The left hand is cool but has no other evidence of ischemia. Which of the following is the most likely etiology of this patient’s condition?
A. Raynaud’s phenomenon
B. Fibromuscular dysplasia
C. Subclavian steal syndrome
D. Aortic coarctation
E. Takayasu arteritis (Correct Answer)
Explanation: ***Takayasu arteritis***
- This **large-vessel vasculitis** predominantly affects **young women** (typically <40 years old) and involves the aorta and its major branches, including the subclavian arteries.
- The patient's **constitutional symptoms** (low-grade fever, night sweats) reflect the systemic inflammatory nature of the disease.
- The **absent left radial pulse**, **unmeasurable left arm blood pressure**, and **subclavian bruit** indicate significant stenosis or occlusion of the left subclavian artery, a hallmark of Takayasu arteritis.
- This arterial stenosis can lead to **subclavian steal syndrome** (a manifestation, not the etiology) and **arm claudication** with exertion (pain when stocking shelves).
- The **normal femoral and pedal pulses** help localize the pathology to the upper extremity vessels.
*Subclavian steal syndrome*
- This is a **hemodynamic phenomenon** (manifestation), not an underlying etiology.
- It occurs when subclavian artery stenosis causes retrograde flow from the vertebral artery to supply the affected arm, which can cause dizziness due to vertebrobasilar insufficiency.
- The underlying **cause** in this young woman with systemic symptoms is most likely Takayasu arteritis.
*Raynaud's phenomenon*
- Characterized by **episodic vasospasm** of digital arteries in response to cold or stress, causing color changes (white-blue-red).
- Does not cause **absent pulses**, **unequal blood pressures between arms**, **bruits**, or **constitutional symptoms**.
*Aortic coarctation*
- A **congenital narrowing of the aorta**, typically just distal to the left subclavian artery origin.
- Would cause **hypertension in both upper extremities** with **diminished lower extremity pulses and blood pressures** (upper-lower discrepancy, not left-right arm discrepancy).
- Does not explain the constitutional symptoms or isolated left arm findings.
*Fibromuscular dysplasia*
- A **noninflammatory arteriopathy** causing abnormal cellular proliferation in arterial walls, most commonly affecting **renal and carotid arteries**.
- Typically occurs in **middle-aged women** without systemic symptoms.
- While it can rarely affect subclavian arteries, the **constitutional symptoms** and pattern of large-vessel involvement strongly favor an inflammatory vasculitis like Takayasu arteritis.
Question 536: A 32-year-old woman comes to the clinic for a routine evaluation. This is her first time visiting this office. Her medical history is significant for cystic medial necrosis of the aorta. Her vital signs include: heart rate 85/min, respiratory rate 15/min, temperature 36.0°C (96.8°F), and blood pressure 110/80 mm Hg. Physical examination shows she is thin and tall with abnormally long extremities and spider-like fingers. Which of the following disorders does the patient most likely have?
A. Cystic fibrosis
B. Marfan syndrome (Correct Answer)
C. Tay-Sachs disease
D. Von Hippel-Lindau disease
E. Fabry disease
Explanation: ***Marfan syndrome***
- The patient's presentation with **cystic medial necrosis of the aorta**, a **tall, thin habitus** with **abnormally long extremities**, and **arachnodactyly (spider-like fingers)** are classic features of Marfan syndrome.
- This is an **autosomal dominant disorder** caused by a defect in the **fibrillin-1 gene (FBN1)**, leading to abnormalities in connective tissue throughout the body, particularly affecting the cardiovascular, ocular, and skeletal systems.
*Cystic fibrosis*
- This is a genetic disorder primarily affecting the **lungs** and **digestive system**, leading to thick, sticky mucus.
- It does not typically present with the skeletal or cardiovascular findings described in the patient, such as tall stature, arachnodactyly, or aortic pathologies.
*Tay-Sachs disease*
- This is a rare, fatal genetic disorder that progressively destroys **nerve cells** in the brain and spinal cord, predominantly affecting infants.
- It is characterized by neurological regression and a **cherry-red spot** on the retina, and does not involve connective tissue abnormalities or aortic disease.
*Von Hippel-Lindau disease*
- This is a genetic disorder characterized by the growth of **tumors** and **cysts** in various parts of the body, including the brain, spinal cord, eyes, kidneys, and pancreas.
- It does not present with the specific skeletal or cardiovascular features observed in the patient, such as arachnodactyly or aortic cystic medial necrosis.
*Fabry disease*
- This is an X-linked lysosomal storage disorder characterized by the accumulation of **globotriaosylceramide** in various tissues, leading to multi-systemic symptoms.
- While it can affect the heart and kidneys, its key features include **acroparesthesias**, **angiokeratomas**, and **corneal opacities**, none of which are mentioned here.
Question 537: A 42-year-old man presents to his physician with dark urine and intermittent flank pain. He has no significant past medical history and generally is healthy. His temperature is 97.5°F (36.4°C), blood pressure is 182/112 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical examination is significant for bilateral palpable flank masses and discomfort to percussion of the costovertebral angle. Urinalysis is positive for red blood cells without any bacteria or nitrites. Which of the following diagnostic modalities should be used to screen members of this patient's family to assess if they are affected by the same condition?
A. Voiding cystourethrogram
B. Abdominal CT
C. Renal biopsy
D. Renal ultrasound (Correct Answer)
E. Genetic sequencing
Explanation: ***Renal ultrasound***
- **Renal ultrasound** is the preferred initial screening method for family members suspected of having **autosomal dominant polycystic kidney disease (ADPKD)** due to its non-invasiveness, accessibility, and high sensitivity for detecting cysts.
- The combination of **bilateral palpable flank masses**, **hypertension**, **dark urine (hematuria)**, and the potential for a family history strongly points to ADPKD.
*Voiding cystourethrogram*
- This imaging study is primarily used to evaluate **vesicoureteral reflux (VUR)** and lower urinary tract anatomy, which is not indicated by the patient's symptoms.
- It involves radiation exposure and catheterization, making it unsuitable for routine screening of asymptomatic family members for ADPKD.
*Abdominal CT*
- While an abdominal CT can visualize renal cysts effectively, it involves **ionizing radiation**, making it less suitable for routine screening of asymptomatic family members compared to ultrasound.
- It would typically be reserved for cases where ultrasound findings are equivocal or for evaluating complications of ADPKD.
*Renal biopsy*
- **Renal biopsy** is an invasive procedure with risks, primarily used to diagnose kidney diseases based on histopathology, especially in cases of unexplained acute kidney injury or glomerular disease.
- It is not a screening tool and would not be performed on asymptomatic family members.
*Genetic sequencing*
- **Genetic testing** can identify specific mutations in *PKD1* or *PKD2* genes, confirming ADPKD, but it is typically reserved for cases where imaging is inconclusive, for family planning, or in atypical presentations.
- It is more expensive and complex than ultrasound, making it a second-line diagnostic tool rather than a primary screening method for a large population of family members.
Question 538: A 60-year-old man presents to the emergency department with pleuritic chest pain. He recently returned from a vacation in Germany and noticed he felt short of breath and had chest pain the following morning. The patient is generally healthy but did have surgery on his ankle 3 weeks ago and has been less ambulatory. His temperature is 99.0°F (37.2°C), blood pressure is 137/88 mm Hg, pulse is 120/min, respirations are 22/min, and oxygen saturation is 96% on room air. Physical exam is notable for a warm and swollen lower extremity. The physician has high clinical suspicion for pulmonary embolism given the patient's risk factors and presentation. Which of the following findings would warrant further workup with a CT angiogram?
A. Bilateral wheezing
B. Green sputum
C. Decreased breath sounds over area of the lung
D. Increased breath sounds over area of the lung
E. Hemoptysis (Correct Answer)
Explanation: ***Hemoptysis***
- **Hemoptysis** (coughing up blood) in the presence of pleuritic chest pain, dyspnea, and risk factors for DVT (recent surgery, immobility, long travel) is a classic symptom of **pulmonary embolism (PE)**, often indicating pulmonary infarction due to arterial occlusion.
- This symptom significantly increases the clinical probability of PE, warranting immediate and definitive diagnostic imaging like a **CT pulmonary angiogram (CTPA)**.
*Bilateral wheezing*
- **Bilateral wheezing** is typically associated with diffuse airway narrowing, as seen in conditions like **asthma** or **COPD**, and is not a specific indicator of pulmonary embolism.
- While it can occur in PE due to bronchoconstriction, it is not a primary or highly specific sign that directly warrants a CT angiogram for PE when other more classic symptoms are present.
*Green sputum*
- **Green sputum** is a strong indicator of a **bacterial infection**, such as pneumonia or acute bronchitis, due to the presence of pus and bacterial products.
- This symptom would lead to workup for infection rather than directly for pulmonary embolism, although pneumonia can sometimes present with similar symptoms.
*Decreased breath sounds over area of the lung*
- While localized **decreased breath sounds** can be seen with PE (e.g., due to atelectasis or pleural effusion), it is a **non-specific finding** that can also be caused by conditions like pneumonia, pleural effusion, or pneumothorax.
- It does not, on its own, provide as strong an indication for PE as hemoptysis, given the other clinical context.
*Increased breath sounds over area of the lung*
- **Increased breath sounds** (e.g., bronchial breath sounds) typically indicate lung consolidation, characteristic of **pneumonia**, where solid tissue transmits sound more efficiently.
- This finding is not associated with pulmonary embolism and would steer the diagnostic workup towards infectious processes rather than PE.
Question 539: A 54-year-old man comes to the emergency department because of severe pain in his right leg that began suddenly 3 hours ago. He has had repeated cramping in his right calf while walking for the past 4 months, but it has never been this severe. He has type 2 diabetes mellitus, hypercholesterolemia, and hypertension. Current medications include insulin, enalapril, aspirin, and simvastatin. He has smoked one pack of cigarettes daily for 33 years. He does not drink alcohol. His pulse is 103/min and blood pressure is 136/84 mm Hg. Femoral pulses are palpable bilaterally. The popliteal and pedal pulses are absent on the right. Laboratory studies show:
Hemoglobin 16.1 g/dL
Serum
Urea nitrogen 14 mg/dL
Glucose 166 mg/dL
Creatinine 1.5 mg/dL
A CT angiogram of the right lower extremity is ordered. Which of the following is the most appropriate next step in management?
A. Administer sodium bicarbonate
B. Administer mannitol
C. Administer normal saline (Correct Answer)
D. Remote ischemic preconditioning
E. Administer heparin anticoagulation
Explanation: ***Administer normal saline***
- The patient has an acute limb ischemia and needs a **CT angiogram** with contrast to locate the thrombus for intervention. Administering **normal saline** prior to contrast administration is crucial to prevent contrast-induced nephropathy, especially in a patient with **diabetes** and mildly elevated **creatinine**.
- **Aggressive hydration** with intravenous fluids helps maintain renal perfusion and dilute the contrast agent, thereby reducing its nephrotoxic effects.
*Administer sodium bicarbonate*
- While sometimes used for renal protection, **sodium bicarbonate** is generally reserved for patients with more severe metabolic acidosis or for specific situations where its alkalizing properties are beneficial.
- In this context, **normal saline** is the primary choice for generalized hydration and prevention of contrast-induced nephropathy before contrast administration.
*Administer mannitol*
- **Mannitol** is an osmotic diuretic used to induce diuresis and reduce intracranial pressure or treat cerebral edema.
- It is **not the primary fluid** for preventing contrast-induced nephropathy and could potentially worsen dehydration if used inappropriately.
*Remote ischemic preconditioning*
- **Remote ischemic preconditioning** involves inducing brief, controlled periods of ischemia and reperfusion in one organ to protect another organ from a subsequent, more prolonged ischemic insult.
- While an interesting concept, it is **not a standard or immediate treatment** for preventing contrast-induced nephropathy in this acute setting and has not shown consistent, strong evidence for this specific indication.
*Administer heparin anticoagulation*
- **Heparin anticoagulation** is critical for treating acute limb ischemia to prevent thrombus propagation. However, the question specifically asks for the most appropriate next step **in management regarding the CT angiogram**.
- While heparin should be given, **renal protection** prior to contrast administration is a more immediate and specific concern related to the ordered diagnostic test. The question asks for the step **before** the CT angiogram.
Question 540: A previously healthy 19-year-old man is brought to the emergency department by his girlfriend after briefly losing consciousness. He passed out while moving furniture into her apartment. She said that he was unresponsive for a minute but regained consciousness and was not confused. The patient did not have any chest pain, palpitations, or difficulty breathing before or after the episode. He has had episodes of dizziness when exercising at the gym. His blood pressure is 125/75 mm Hg while supine and 120/70 mm Hg while standing. Pulse is 70/min while supine and 75/min while standing. On examination, there is a grade 3/6 systolic murmur at the left lower sternal border and a systolic murmur at the apex, both of which disappear with passive leg elevation. Which of the following is the most likely cause?
A. Prolonged QT interval
B. Hypertrophic cardiomyopathy (Correct Answer)
C. Mitral valve stenosis
D. Mitral valve prolapse
E. Bicuspid aortic valve
Explanation: ***Hypertrophic cardiomyopathy***
- This patient's **syncope associated with exertion** (moving furniture) and episodes of **dizziness during exercise** are highly suggestive of hypertrophic cardiomyopathy (HCM).
- The presence of a **systolic murmur at the left sternal border and apex** that **decreases/disappears with passive leg elevation** indicates a dynamic left ventricular outflow tract (LVOT) obstruction that is sensitive to preload changes, a hallmark of HCM.
- Passive leg elevation **increases preload** → **increases LV volume** → **decreases LVOT obstruction** → **decreases murmur intensity**.
*Prolonged QT interval*
- While it can cause syncope, especially exertional, a prolonged QT interval generally **does not present with dynamic murmurs** that change with preload.
- ECG findings (not mentioned here) would be the primary diagnostic clue, not physical exam findings related to murmurs.
*Mitral valve stenosis*
- Mitral stenosis would typically present with a **diastolic murmur** (not systolic) and symptoms like dyspnea, fatigue, and possibly hemoptysis due to elevated left atrial pressure.
- The murmur of mitral stenosis would not characteristically change with passive leg elevation in the manner described.
*Mitral valve prolapse*
- Mitral valve prolapse often presents with a **mid-systolic click** followed by a systolic murmur, which typically **intensifies with standing** or maneuvers that decrease left ventricular volume.
- The murmur described here decreases with leg elevation (increased preload), which is the opposite behavior of a mitral prolapse murmur.
*Bicuspid aortic valve*
- A bicuspid aortic valve can cause an **aortic stenosis murmur** (a systolic ejection murmur heard best at the right upper sternal border) or regurgitation, but it generally **does not cause a dynamic murmur that changes with preload** in this characteristic fashion.
- Symptoms related to bicuspid aortic valve disease (like syncope) would more commonly be associated with significant stenosis, not with a murmur that is acutely sensitive to preload changes.