A 74-year-old man is brought to the physician by his wife for progressively worsening confusion and forgetfulness. Vital signs are within normal limits. Physical examination shows a flat affect and impaired short-term memory. An MRI of the brain is shown. Further evaluation of this patient is most likely to show which of the following findings?
Q382
A 20-year-old woman visits the clinic for her annual physical examination. She does not have any complaints during this visit. The past medical history is insignificant. She follows a healthy lifestyle with a balanced diet and moderate exercise schedule. She does not smoke or drink alcohol. She does not take any medications currently. The family history is significant for her grandfather and uncle who had their parathyroid glands removed. The vital signs include: blood pressure:122/88 mm Hg, pulse 88/min, respirations 17/min, and temperature 36.7°C (98.0°F). The physical exam is within normal limits. The lab test results are as follows:
Blood Urea Nitrogen 12 mg/dL
Serum Creatinine 1.1 mg/dL
Serum Glucose (Random) 88 mg/dL
Serum chloride 107 mmol/L
Serum potassium 4.5 mEq/L
Serum sodium 140 mEq/L
Serum calcium 14.5 mg/dL
Serum albumin 4.4 gm/dL
Parathyroid Hormone (PTH) 70 pg/mL (Normal: 10-65 pg/mL)
24-Hr urinary calcium 85 mg/day (Normal: 100–300 mg/day)
Which of the following is the next best step in the management of this patient?
Q383
A 74-year-old woman is brought to the physician by her daughter for worsening memory for the past 1 month. She can no longer manage her bills and frequently forgets the names of her children. Her daughter is also concerned that her mother has a urinary tract infection because she has had increased urinary urgency and several episodes of urinary incontinence. Vital signs are within normal limits. Physical examination shows poor short-term memory recall and a slow gait with wide, short steps. Which of the following is most likely to improve this patient's condition?
Q384
A 48-year-old woman comes to the physician because of an increasingly painful swelling behind her right knee for the past 2 months. During this time, she has also had intermittent low-grade fever and she has been more fatigued than usual. She has not had any trauma to the knee. Over the past year, she has had occasional pain in her hands and wrists bilaterally. She has hypertension and type 2 diabetes mellitus. She drinks 1–2 glasses of wine daily and occasionally more on weekends. Current medications include enalapril, metformin, and glimepiride. Her mother and older brother have osteoarthritis. She is 165 cm (5 ft 5 in) tall and weighs 68 kg (150 lb); BMI is 25 kg/m2. Vital signs are within normal limits. Examination shows a 3-cm nontender mass in the right popliteal fossa that becomes prominent when the knee is extended. There is mild swelling and redness of her right knee joint. Which of the following is the most likely diagnosis?
Q385
A 24-year-old woman presents with episodic shortness of breath, chest tightness, and wheezing. She has noticed an increased frequency of such episodes in the spring season. She also has a history of urticaria. She has smoked a half pack of cigarettes per day over the last 5 years. Her mother also has similar symptoms. The physical exam is within normal limits. Which of the following findings is characteristic of her condition?
Q386
A 55-year-old man with a BMI of 34 kg/m² presents to his primary care physician for knee pain. The patient has had left knee pain, which has been steadily worsening for the past year. He states that ice and rest has led to minor improvement in his symptoms. He recently bumped his knee; however, he says that it has not altered his baseline pain when ambulating. The patient is a butcher and lives with his wife. His current medications include insulin, metformin, hydrochlorothiazide, and lisinopril. He is attending Alcoholics Anonymous with little success. Physical exam reveals a left knee that is mildly erythematous with some bruising. There is no pain upon palpation of the joint or with passive range of motion. The patient exhibits a mildly antalgic gait. Which of the following is the best initial step in management?
Q387
A 25-year-old woman presents to her primary care clinic for a general checkup. She states she's been a bit more fatigued lately during finals season but is otherwise well. Her mother and sister have hypothyroidism. She denies weight gain, cold intolerance, constipation, heavy or irregular menses, or changes in the quality of her hair, skin, or nails. Physical exam is unremarkable. Laboratory studies are ordered as seen below.
Hemoglobin: 14 g/dL
Hematocrit: 40%
Leukocyte count: 5,500/mm^3 with normal differential
Platelet count: 188,000/mm^3
Serum:
Na+: 139 mEq/L
Cl-: 102 mEq/L
K+: 4.4 mEq/L
HCO3-: 24 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 0.8 mg/dL
Ca2+: 10.2 mg/dL
Antithyroid peroxidase Ab: Positive
AST: 12 U/L
ALT: 10 U/L
Which of the following laboratory values is most likely in this patient?
Q388
A 43-year-old woman presents to her primary care physician with complaints of mild shortness of breath and right-sided chest pain for three days. She reports that lately she has had a nagging nonproductive cough and low-grade fevers. On examination, her vital signs are: temperature 99.1 deg F (37.3 deg C), blood pressure is 115/70 mmHg, pulse is 91/min, respirations are 17/min, and oxygen saturation 97% on room air. She is well-appearing, with normal work of breathing, and no leg swelling. She is otherwise healthy, with no prior medical or surgical history, currently taking no medications. The attending has a low suspicion for the most concerning diagnosis and would like to exclude it with a very sensitive though non-specific test. Which of the following should this physician order?
Q389
A 75-year-old woman presents with sudden loss of vision. She says that she was reading when suddenly she was not able to see the print on half of the page. Her symptoms started 4 hours ago and are accompanied by a severe posterior headache. Vital signs reveal the following: blood pressure 119/76 mm Hg, pulse 89/min, SpO2 98% on room air. The patient was unable to recognize her niece when she arrived to see her. A noncontrast CT of the head shows no evidence of hemorrhagic stroke. What is the most likely diagnosis in this patient?
Q390
A 49-year-old man is referred to a cardiologist by his primary care provider (PCP) for a new heart murmur. He otherwise feels well and has no complaints. He had not seen a doctor in the last 15 years but finally went to his PCP for a check-up at the urging of his girlfriend. His past medical history is notable for gastroesophageal reflux disease, hypertension, and hepatitis B. He takes omeprazole and lisinopril. He has a prior history of intravenous drug abuse and a 50-pack-year smoking history. He has had many prior sexual partners and uses protection intermittently. He reports that he may have had a sore on his penis many years ago, but it went away without treatment. His temperature is 99°F (37.2°C), blood pressure is 141/91 mmHg, pulse is 89/min, and respirations are 18/min. On exam, S1 is normal and S2 has a tambour-like quality. There is a visible and palpable pulsation in the suprasternal notch and a diastolic decrescendo murmur over the right upper sternal border. A chest radiograph demonstrates calcification of the aortic root. Which of the following is the most likely cause of this patient's condition?
Cardiology US Medical PG Practice Questions and MCQs
Question 381: A 74-year-old man is brought to the physician by his wife for progressively worsening confusion and forgetfulness. Vital signs are within normal limits. Physical examination shows a flat affect and impaired short-term memory. An MRI of the brain is shown. Further evaluation of this patient is most likely to show which of the following findings?
A. Postural instability
B. Pill-rolling tremor
C. Choreiform movements
D. Broad-based gait (Correct Answer)
E. Papilledema
Explanation: ***Broad-based gait***
- The patient's symptoms of **confusion**, **forgetfulness (dementia)**, and the MRI finding of **hydrocephalus** (dilated ventricles without sulcal effacement) are classic for **Normal Pressure Hydrocephalus (NPH)**.
- A hallmark triad of NPH includes **dementia**, **gait disturbance** (often described as broad-based or magnetic), and **urinary incontinence**.
*Postural instability*
- While patients with NPH can have **postural instability**, a more specific and prominent gait disturbance is typically observed.
- **Postural instability** is also a feature of many other neurological conditions, making it less specific than a broad-based gait for NPH.
*Pill-rolling tremor*
- A **pill-rolling tremor** is a characteristic feature of **Parkinson's disease**, which presents with a different constellation of symptoms, including bradykinesia and rigidity, and is not directly associated with hydrocephalus.
- This type of tremor is a **resting tremor** and is not typically seen in NPH.
*Choreiform movements*
- **Choreiform movements** are involuntary, brief, abrupt, and irregular movements, characteristic of conditions like **Huntington's disease**.
- These movements are not a typical manifestation of NPH, which primarily involves gait, cognition, and continence.
*Papilledema*
- **Papilledema** is swelling of the optic disc due to **increased intracranial pressure**.
- While hydrocephalus can cause increased intracranial pressure, NPH is characterized by **normal intracranial pressure**, hence papilledema is not expected.
Question 382: A 20-year-old woman visits the clinic for her annual physical examination. She does not have any complaints during this visit. The past medical history is insignificant. She follows a healthy lifestyle with a balanced diet and moderate exercise schedule. She does not smoke or drink alcohol. She does not take any medications currently. The family history is significant for her grandfather and uncle who had their parathyroid glands removed. The vital signs include: blood pressure:122/88 mm Hg, pulse 88/min, respirations 17/min, and temperature 36.7°C (98.0°F). The physical exam is within normal limits. The lab test results are as follows:
Blood Urea Nitrogen 12 mg/dL
Serum Creatinine 1.1 mg/dL
Serum Glucose (Random) 88 mg/dL
Serum chloride 107 mmol/L
Serum potassium 4.5 mEq/L
Serum sodium 140 mEq/L
Serum calcium 14.5 mg/dL
Serum albumin 4.4 gm/dL
Parathyroid Hormone (PTH) 70 pg/mL (Normal: 10-65 pg/mL)
24-Hr urinary calcium 85 mg/day (Normal: 100–300 mg/day)
Which of the following is the next best step in the management of this patient?
A. No treatment is necessary (Correct Answer)
B. Start IV fluids to keep her hydrated
C. Start her on pamidronate
D. Give glucocorticoids
E. Parathyroidectomy
Explanation: ***No treatment is necessary***
- This patient has **familial hypocalciuric hypercalcemia (FHH)**, a benign autosomal dominant condition caused by inactivating mutations in the calcium-sensing receptor (CaSR).
- The key diagnostic triad is: **elevated serum calcium** (14.5 mg/dL), **mildly elevated or inappropriately normal PTH** (70 pg/mL), and **LOW 24-hour urinary calcium** (<100 mg/day).
- The family history of parathyroid surgery in relatives suggests they may have been misdiagnosed with primary hyperparathyroidism.
- **FHH is a benign condition that requires no treatment**. Patients are typically asymptomatic and do not develop complications of hypercalcemia.
- The calcium-creatinine clearance ratio (CCCR) is typically <0.01 in FHH, which helps distinguish it from primary hyperparathyroidism (CCCR >0.02).
*Parathyroidectomy*
- **Parathyroidectomy is contraindicated in FHH** and is a common error in management.
- Surgery does not correct the hypercalcemia in FHH because the defect is in the calcium-sensing receptor throughout the body, not in the parathyroid glands.
- Parathyroidectomy can lead to **permanent hypoparathyroidism** without resolving the underlying condition.
- Surgery is indicated for **primary hyperparathyroidism**, which differs from FHH by having normal or elevated urinary calcium excretion.
*Start IV fluids to keep her hydrated*
- IV fluids are used for **acute symptomatic hypercalcemia** or hypercalcemic crisis.
- This patient is **asymptomatic** with stable vital signs and does not require acute intervention.
- Fluids do not address the underlying pathophysiology of FHH and are unnecessary in this benign condition.
*Start her on pamidronate*
- Bisphosphonates like pamidronate are used for **hypercalcemia of malignancy** or severe symptomatic primary hyperparathyroidism.
- They are **ineffective in FHH** because the hypercalcemia is due to altered calcium sensing, not increased bone resorption.
- Pamidronate is not indicated for chronic management of asymptomatic hypercalcemia due to FHH.
*Give glucocorticoids*
- Glucocorticoids treat hypercalcemia from **granulomatous diseases** (sarcoidosis), **vitamin D intoxication**, or **hematologic malignancies** (lymphoma, multiple myeloma).
- They work by decreasing intestinal calcium absorption and are ineffective in FHH.
- This patient's clinical presentation and laboratory findings do not suggest any of these conditions.
Question 383: A 74-year-old woman is brought to the physician by her daughter for worsening memory for the past 1 month. She can no longer manage her bills and frequently forgets the names of her children. Her daughter is also concerned that her mother has a urinary tract infection because she has had increased urinary urgency and several episodes of urinary incontinence. Vital signs are within normal limits. Physical examination shows poor short-term memory recall and a slow gait with wide, short steps. Which of the following is most likely to improve this patient's condition?
A. Bromocriptine therapy
B. Vaginal pessary placement
C. Cerebral shunt placement (Correct Answer)
D. Donepezil therapy
E. Ciprofloxacin therapy
Explanation: ***Cerebral shunt placement***
- This patient presents with a classic triad of **dementia**, **urinary incontinence**, and **gait disturbance (ataxia)**, highly suggestive of **normal pressure hydrocephalus (NPH)**.
- **Cerebral shunt placement** (e.g., ventriculoperitoneal shunt) is the definitive treatment for NPH, rerouting excess CSF and often leading to significant improvement in symptoms, especially gait and incontinence.
*Bromocriptine therapy*
- **Bromocriptine** is a **dopamine agonist** primarily used in the treatment of **Parkinson's disease** and **hyperprolactinemia**.
- There is no evidence to support its use in improving cognitive or gait symptoms related to normal pressure hydrocephalus.
*Vaginal pessary placement*
- A **vaginal pessary** is used to support pelvic organs and treat **pelvic organ prolapse** or **stress urinary incontinence**.
- While the patient has urinary incontinence, her other symptoms of dementia and gait disturbance point to a central neurological cause rather than a purely gynecological issue.
*Donepezil therapy*
- **Donepezil** is an **acetylcholinesterase inhibitor** used to treat the cognitive symptoms of **Alzheimer's disease** and other dementias.
- While the patient has dementia, the combination of gait disturbance and urinary incontinence makes NPH a more likely diagnosis than Alzheimer's, and donepezil would not address the underlying pathology of NPH.
*Ciprofloxacin therapy*
- **Ciprofloxacin** is an antibiotic used to treat bacterial infections, including **urinary tract infections (UTIs)**.
- Although the patient has urinary symptoms, the presence of dementia and gait disturbance suggests a systemic neurological cause (NPH) rather than just an isolated UTI, and antibiotics would not address these broader issues.
Question 384: A 48-year-old woman comes to the physician because of an increasingly painful swelling behind her right knee for the past 2 months. During this time, she has also had intermittent low-grade fever and she has been more fatigued than usual. She has not had any trauma to the knee. Over the past year, she has had occasional pain in her hands and wrists bilaterally. She has hypertension and type 2 diabetes mellitus. She drinks 1–2 glasses of wine daily and occasionally more on weekends. Current medications include enalapril, metformin, and glimepiride. Her mother and older brother have osteoarthritis. She is 165 cm (5 ft 5 in) tall and weighs 68 kg (150 lb); BMI is 25 kg/m2. Vital signs are within normal limits. Examination shows a 3-cm nontender mass in the right popliteal fossa that becomes prominent when the knee is extended. There is mild swelling and redness of her right knee joint. Which of the following is the most likely diagnosis?
A. Rheumatoid arthritis (Correct Answer)
B. Systemic lupus erythematosus
C. Popliteal artery aneurysm
D. Osteoarthritis
E. Psoriatic arthritis
Explanation: ***Rheumatoid arthritis***
- The patient's presentation with **bilateral hand and wrist pain**, along with **fatigue**, **low-grade fever**, and a **Baker's cyst** (swelling in the popliteal fossa) is highly suggestive of **rheumatoid arthritis (RA)**. The mild swelling and redness of the knee further support an inflammatory arthropathy.
- While a Baker's cyst can appear in other conditions, its presence in combination with symmetrical small joint pain and systemic symptoms points towards the chronic inflammation seen in RA.
*Systemic lupus erythematosus*
- Although SLE can cause **arthralgias** and fatigue, it typically presents with other classic features such as a **malar rash**, photosensitivity, serositis, and renal involvement, none of which are described.
- A Baker's cyst is not a common primary manifestation of SLE, and the predominant focus on joint inflammation with systemic symptoms makes RA a more fitting diagnosis.
*Popliteal artery aneurysm*
- A popliteal artery aneurysm would typically present as a **pulsatile mass** behind the knee, often associated with symptoms of **ischemia** in the lower limb.
- The patient's mass is described as "nontender" and becomes prominent on knee extension, which is characteristic of a Baker's cyst, not a vascular aneurysm.
*Osteoarthritis*
- Osteoarthritis usually causes **deep, aching joint pain** that **worsens with activity** and improves with rest, and is often asymmetrical.
- The patient's symptoms of **inflammatory arthritis**, including low-grade fever and fatigue, along with bilateral small joint involvement, are not typical of osteoarthritis despite a family history.
*Psoriatic arthritis*
- Psoriatic arthritis is associated with **psoriasis** (skin lesions) or a family history of psoriasis, and often presents with **enthesitis**, dactylitis, or distinctive nail changes.
- The patient has no history or clinical signs suggesting psoriasis, making psoriatic arthritis less likely than RA, given the symmetrical small joint pain and systemic inflammatory features.
Question 385: A 24-year-old woman presents with episodic shortness of breath, chest tightness, and wheezing. She has noticed an increased frequency of such episodes in the spring season. She also has a history of urticaria. She has smoked a half pack of cigarettes per day over the last 5 years. Her mother also has similar symptoms. The physical exam is within normal limits. Which of the following findings is characteristic of her condition?
A. Increased oxygen saturation
B. Decrease in forced expiratory volume in 1 second (FEV1) after methacholine (Correct Answer)
C. Decreased forced vital capacity (FVC) on pulmonary tests
D. Paroxysmal nocturnal dyspnea
E. Chest X-ray showing hyperinflation
Explanation: ***Decrease in forced expiratory volume in 1 second (FEV1) after methacholine***
- The patient's symptoms of **episodic shortness of breath, chest tightness, and wheezing**, especially with seasonal variability and a history of **urticaria** and maternal history of similar symptoms, are highly suggestive of **asthma**.
- A significant **decrease in FEV1 after methacholine challenge** is a hallmark of bronchial hyperresponsiveness, which is diagnostic for asthma.
*Increased oxygen saturation*
- While a patient with asthma might have normal oxygen saturation during an asymptomatic period, during an **acute asthma exacerbation**, oxygen saturation would likely be decreased, not increased.
- Increased oxygen saturation is not a characteristic finding and does not help diagnose asthma.
*Decreased forced vital capacity (FVC) on pulmonary tests*
- Although **FVC can be reduced in severe asthma** due to air trapping, it is not the primary or most characteristic pulmonary function test finding.
- The hallmark of asthma is **airflow obstruction**, specifically a reduced FEV1/FVC ratio and reduced FEV1, which is reversible.
*Paroxysmal nocturnal dyspnea*
- **Paroxysmal nocturnal dyspnea (PND)** is typically associated with **heart failure**, where fluid accumulation in the lungs worsens when lying flat, causing shortness of breath that awakens the patient from sleep.
- While some asthmatics may experience nocturnal symptoms, PND is not a defining characteristic of asthma.
*Chest X-ray showing hyperinflation*
- A **chest X-ray is typically normal in asthma** unless there is an exacerbation or complications like pneumonia or pneumothorax.
- **Hyperinflation** can be seen in severe, prolonged asthma or during an acute attack due to air trapping, but it is not a *characteristic diagnostic feature* during asymptomatic periods or generally for diagnosis.
Question 386: A 55-year-old man with a BMI of 34 kg/m² presents to his primary care physician for knee pain. The patient has had left knee pain, which has been steadily worsening for the past year. He states that ice and rest has led to minor improvement in his symptoms. He recently bumped his knee; however, he says that it has not altered his baseline pain when ambulating. The patient is a butcher and lives with his wife. His current medications include insulin, metformin, hydrochlorothiazide, and lisinopril. He is attending Alcoholics Anonymous with little success. Physical exam reveals a left knee that is mildly erythematous with some bruising. There is no pain upon palpation of the joint or with passive range of motion. The patient exhibits a mildly antalgic gait. Which of the following is the best initial step in management?
A. Rest for 1-2 weeks
B. Colchicine
C. Aspirin
D. MRI
E. Weight loss (Correct Answer)
Explanation: ***Weight loss***
- The patient has **obesity (BMI 34 kg/m²)** and several risk factors for **osteoarthritis**, including age (55), chronic knee pain, occupational stress (butcher), and an antalgic gait.
- **Weight reduction** is the most important initial conservative management for osteoarthritis in obese patients, as it significantly reduces mechanical stress on weight-bearing joints like the knee, improves pain, and slows disease progression.
- Every pound of weight lost reduces knee joint load by approximately 4 pounds, making weight loss one of the most effective interventions for symptomatic relief and disease modification.
- Given the patient's diabetes and cardiovascular risk factors, weight loss also addresses multiple comorbidities simultaneously.
*Rest for 1-2 weeks*
- While rest can temporarily alleviate symptoms in acute exacerbations, prolonged rest for 1-2 weeks is generally **not the best long-term initial management** for chronic knee pain caused by osteoarthritis, and it may lead to deconditioning and muscle atrophy.
- The patient's pain has been steadily worsening for a year, suggesting a chronic issue where activity modification and weight loss are more beneficial than complete immobility.
*Colchicine*
- **Colchicine** is primarily used for diagnosing and treating **gout**, which is not strongly indicated here despite the patient's alcohol use and diabetes (risk factors for gout).
- Although the patient has mild erythema and bruising, the bruising is explained by recent trauma, and there are no classic signs of an acute gout attack, such as severe pain, rapid onset, or specific joint involvement like the first metatarsophalangeal joint.
- The absence of pain on palpation makes gout unlikely.
*Aspirin*
- **Aspirin** is an NSAID and can provide symptomatic pain relief, but it does not address the underlying mechanical cause of osteoarthritis in an obese patient.
- Given the patient's existing medications (lisinopril, HCTZ) and diabetes, adding NSAIDs like aspirin could increase the risk of adverse effects such as **renal dysfunction**, gastrointestinal bleeding, and fluid retention.
- NSAIDs are better used as adjunctive therapy after addressing fundamental issues like excess weight.
*MRI*
- While an MRI can provide detailed images of knee structures, it is generally **not the initial step** for chronic knee pain suggestive of osteoarthritis.
- Clinical diagnosis and plain radiographs are usually sufficient for initial evaluation of osteoarthritis, and an MRI would typically be reserved for cases where other pathologies (meniscal tears, ligamentous injuries) are suspected or when surgery is being considered.
- Imaging does not change the initial management recommendation of weight loss in this obese patient with clinical osteoarthritis.
Question 387: A 25-year-old woman presents to her primary care clinic for a general checkup. She states she's been a bit more fatigued lately during finals season but is otherwise well. Her mother and sister have hypothyroidism. She denies weight gain, cold intolerance, constipation, heavy or irregular menses, or changes in the quality of her hair, skin, or nails. Physical exam is unremarkable. Laboratory studies are ordered as seen below.
Hemoglobin: 14 g/dL
Hematocrit: 40%
Leukocyte count: 5,500/mm^3 with normal differential
Platelet count: 188,000/mm^3
Serum:
Na+: 139 mEq/L
Cl-: 102 mEq/L
K+: 4.4 mEq/L
HCO3-: 24 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 0.8 mg/dL
Ca2+: 10.2 mg/dL
Antithyroid peroxidase Ab: Positive
AST: 12 U/L
ALT: 10 U/L
Which of the following laboratory values is most likely in this patient?
A. Elevated TSH and low T4
B. Elevated TSH and elevated T4
C. Normal TSH and low T4
D. Normal TSH and normal T4 (Correct Answer)
E. Low TSH and elevated T4
Explanation: ***Normal TSH and normal T4***
- The patient has a **positive antithyroid peroxidase antibody**, indicating **Hashimoto's thyroiditis**, but she is currently **euthyroid** as evidenced by the absence of typical hypothyroid symptoms.
- In the initial stages of Hashimoto's thyroiditis, the thyroid gland often functions normally, leading to **normal TSH and T4 levels**, even with positive antibodies.
*Elevated TSH and low T4*
- This pattern indicates **overt hypothyroidism**, which would be expected to cause symptoms like **weight gain, cold intolerance, and constipation**, none of which are present in this patient.
- While Hashimoto's thyroiditis can progress to this stage, the patient's current presentation is subclinical, without biochemical evidence of hypofunction.
*Elevated TSH and elevated T4*
- This combination is rare and typically suggests **TSH-producing pituitary adenoma** or **thyroid hormone resistance**, neither of which is indicated by the patient's symptoms or family history.
- An elevated TSH would normally stimulate the thyroid to produce more T4, but if TSH is also elevated, it points to a problem at the pituitary level.
*Normal TSH and low T4*
- This pattern is highly suggestive of **central (secondary) hypothyroidism**, where the pituitary gland is not producing enough TSH to stimulate the thyroid.
- Given the patient's family history of hypothyroidism and positive antithyroid peroxidase antibodies (suggesting a primary thyroid issue), central hypothyroidism is less likely.
*Low TSH and elevated T4*
- This indicates **hyperthyroidism** (e.g., Graves' disease or toxic goiter), which would present with symptoms like **weight loss, heat intolerance, and tachycardia**, which are absent in this patient.
- While positive antithyroid antibodies can sometimes be seen in Graves' disease, the patient's lack of hyperthyroid symptoms rules out this state.
Question 388: A 43-year-old woman presents to her primary care physician with complaints of mild shortness of breath and right-sided chest pain for three days. She reports that lately she has had a nagging nonproductive cough and low-grade fevers. On examination, her vital signs are: temperature 99.1 deg F (37.3 deg C), blood pressure is 115/70 mmHg, pulse is 91/min, respirations are 17/min, and oxygen saturation 97% on room air. She is well-appearing, with normal work of breathing, and no leg swelling. She is otherwise healthy, with no prior medical or surgical history, currently taking no medications. The attending has a low suspicion for the most concerning diagnosis and would like to exclude it with a very sensitive though non-specific test. Which of the following should this physician order?
A. Obtain chest radiograph
B. Obtain spiral CT chest with IV contrast
C. Order a lower extremity ultrasound
D. Order a D-dimer (Correct Answer)
E. Obtain ventilation-perfusion scan
Explanation: ***Order a D-dimer***
- The physician has a **low suspicion based on clinical assessment** and wants to **exclude** a concerning diagnosis (likely **pulmonary embolism** or PE) using a **sensitive test**. A negative D-dimer test can effectively rule out PE in patients with a low pre-test probability.
- The D-dimer is a product of **fibrin degradation** and its elevation indicates recent or ongoing **thrombus formation** and lysis. It is highly sensitive for PE but has low specificity.
*Obtain chest radiograph*
- A chest radiograph is often **normal in pulmonary embolism** or may show non-specific findings, making it unsuitable for ruling out PE.
- While useful for diagnosing other conditions like pneumonia or pleural effusions, it is **not sensitive enough to exclude PE**.
*Obtain spiral CT chest with IV contrast*
- A **spiral CT chest with IV contrast (CT pulmonary angiography)** is the gold standard for diagnosing PE, but it is **not a sensitive rule-out test** for low-probability cases.
- It involves **radiation exposure** and **contrast administration**, which are generally avoided if a less invasive, equally effective rule-out test is available for low-risk patients.
*Order a lower extremity ultrasound*
- Lower extremity ultrasound is used to diagnose **deep vein thrombosis (DVT)**, which is a common source of PE.
- While DVT can lead to PE, a negative lower extremity ultrasound **does not rule out PE** itself, as the clot may have already embolized or originated from elsewhere.
*Obtain ventilation-perfusion scan*
- A **ventilation-perfusion (V/Q) scan** is an alternative to CT angiography for diagnosing PE, particularly in patients with contraindications to contrast.
- However, it is **less definitive than CTPA** and is typically used when suspicion for PE is moderate or higher, rather than as a primary rule-out test for low-probability patients.
Question 389: A 75-year-old woman presents with sudden loss of vision. She says that she was reading when suddenly she was not able to see the print on half of the page. Her symptoms started 4 hours ago and are accompanied by a severe posterior headache. Vital signs reveal the following: blood pressure 119/76 mm Hg, pulse 89/min, SpO2 98% on room air. The patient was unable to recognize her niece when she arrived to see her. A noncontrast CT of the head shows no evidence of hemorrhagic stroke. What is the most likely diagnosis in this patient?
A. Lacunar stroke
B. Middle cerebral artery stroke
C. Vertebrobasilar stroke
D. Subarachnoid hemorrhage
E. Posterior cerebral artery stroke (Correct Answer)
Explanation: ***Posterior cerebral artery stroke***
- The sudden severe posterior headache along with **unilateral vision loss** and **prosopagnosia** (inability to recognize familiar faces) are characteristic signs of a **posterior cerebral artery (PCA) stroke**.
- PCA occlusion often affects the **occipital lobe** (vision) and can extend to the **temporal lobe** (facial recognition).
*Lacunar stroke*
- This type of stroke results from the occlusion of small penetrating arteries and typically causes **pure motor** or **pure sensory deficits**, not complex visual or recognition problems.
- While headache can occur, the specific combination of symptoms points away from a lacunar infarct.
*Middle cerebral artery stroke*
- MCA stroke commonly presents with **contralateral hemiparesis**, **aphasia** (if dominant hemisphere), and **hemianopia** but usually not isolated unilateral vision loss or severe posterior headache with prosopagnosia.
- The symptoms are more consistent with involvement of the posterior circulation.
*Vertebrobasilar stroke*
- A vertebrobasilar stroke can cause **visual disturbances**, but it is typically associated with other **brainstem symptoms** like vertigo, ataxia, or cranial nerve deficits, which are not described here.
- The specific presentation of unilateral vision loss and prosopagnosia is less typical for a vertebrobasilar stroke affecting widespread brainstem structures.
*Subarachnoid hemorrhage*
- While a **sudden severe headache (thunderclap headache)** is a hallmark of SAH, it usually presents with meningeal irritation symptoms like **neck stiffness** and often altered mental status, and the visual deficits are usually different (e.g., oculomotor nerve palsy).
- The patient's focal neurological deficits, specifically prosopagnosia and unilateral visual field loss, are more indicative of an ischemic event in a specific vascular territory.
Question 390: A 49-year-old man is referred to a cardiologist by his primary care provider (PCP) for a new heart murmur. He otherwise feels well and has no complaints. He had not seen a doctor in the last 15 years but finally went to his PCP for a check-up at the urging of his girlfriend. His past medical history is notable for gastroesophageal reflux disease, hypertension, and hepatitis B. He takes omeprazole and lisinopril. He has a prior history of intravenous drug abuse and a 50-pack-year smoking history. He has had many prior sexual partners and uses protection intermittently. He reports that he may have had a sore on his penis many years ago, but it went away without treatment. His temperature is 99°F (37.2°C), blood pressure is 141/91 mmHg, pulse is 89/min, and respirations are 18/min. On exam, S1 is normal and S2 has a tambour-like quality. There is a visible and palpable pulsation in the suprasternal notch and a diastolic decrescendo murmur over the right upper sternal border. A chest radiograph demonstrates calcification of the aortic root. Which of the following is the most likely cause of this patient's condition?
A. Tricuspid valve inflammation
B. Pericardial inflammation
C. Fibrinous plaque formation in the arterial intima
D. Neoplastic growth in the cardiac atria
E. Vasa vasorum destruction (Correct Answer)
Explanation: ***Vasa vasorum destruction***
- The patient's presentation with a **diastolic decrescendo murmur** over the right upper sternal border, pulsatile suprasternal notch, and **aortic root calcification** is highly suggestive of **aortic regurgitation** due to a dilated aortic root. This, coupled with a history of a penile sore that resolved spontaneously, raises strong suspicion for **tertiary syphilis**.
- **Tertiary syphilis** can lead to **aortitis**, an inflammation of the **aorta's vasa vasorum**, causing their obliteration and subsequently weakening the aortic wall, leading to **aneurysm formation** and **aortic valve insufficiency**. This can result in the "tambour-like" S2 sound due to aortic root dilation.
*Fibrinous plaque formation in the arterial intima*
- This description is characteristic of **atherosclerosis**, which can affect the aorta but typically causes **stenotic lesions** or aneurysms that are not primarily associated with the specific murmur and tambour S2 described here in the context of this patient's risk factors.
- While **atherosclerosis** can contribute to aortic stiffness and calcification, it is less likely to directly cause the specific constellation of findings (particularly the "tambour-like" S2 and historical penile sore suggestive of syphilis) compared to syphilitic aortitis.
*Neoplastic growth in the cardiac atria*
- **Cardiac tumors**, such as **atrial myxomas**, can cause murmurs and systemic symptoms, but they typically obstruct blood flow or cause embolic phenomena and would not explain the **diastolic decrescendo murmur** at the right upper sternal border, **aortic root calcification**, or the tambour-like S2.
- These tumors are not directly linked to a history of a penile sore or intravenous drug use in a way that explains the cardiovascular findings in this case.
*Tricuspid valve inflammation*
- **Tricuspid valve inflammation** or endocarditis is common in intravenous drug users and would typically cause a **systolic murmur** (regurgitation) or **diastolic murmur** (stenosis) best heard at the left sternal border and would not explain the aortic root calcification or the tambour S2.
- While the patient has a history of IV drug abuse, the physical exam findings strongly point to aortic valve pathology rather than tricuspid valve issues.
*Pericardial inflammation*
- **Pericardial inflammation (pericarditis)** can cause chest pain, a pericardial friction rub, and sometimes effusions, but it does not cause a **diastolic decrescendo murmur** indicative of aortic regurgitation or a tambour S2.
- While it can be a manifestation of systemic diseases, the specific murmur and imaging findings are not characteristic of pericarditis.