Three days after undergoing open surgery to repair a bilateral inguinal hernia, a 66-year-old man has new, intermittent upper abdominal discomfort that worsens when he walks around. He also has new shortness of breath that resolves with rest. There were no complications during surgery or during the immediate postsurgical period. Ambulation was restarted on the first postoperative day. He has type 2 diabetes mellitus, hypercholesterolemia, and hypertension. He has smoked one pack of cigarettes daily for 25 years. Prior to admission, his medications included metformin, simvastatin, and lisinopril. His temperature is 37°C (98.6°F), pulse is 80/min, respirations are 16/min, and blood pressure is 129/80 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. The abdomen is soft and shows two healing surgical scars with moderate serous discharge. Cardiopulmonary examination shows no abnormalities. An ECG at rest shows no abnormalities. Cardiac enzyme levels are within the reference range. An x-ray of the chest and abdominal ultrasonography show no abnormalities. Which of the following is the most appropriate next step in diagnosis?
Q712
A 35-year-old woman who was recently ill with an upper respiratory infection presents to the emergency department with weakness in her lower limbs and difficulty breathing. Her symptoms began with a burning sensation in her toes along with numbness. She claims that the weakness has been getting worse over the last few days and now involving her arms and face. Currently, she is unable to get up from the chair without some assistance. Her temperature is 37.0°C (98.6°F), the blood pressure is 145/89 mm Hg, the heart rate is 99/min, the respiratory rate is 12/min, and the oxygen saturation is 95% on room air. On physical examination, she has diminished breath sounds on auscultation of bilateral lung fields with noticeably poor inspiratory effort. Palpation of the lower abdomen reveals a palpable bladder. Strength is 3 out of 5 symmetrically in the lower extremities bilaterally. The sensation is intact. What is the most likely diagnosis?
Q713
A 56-year-old woman presents with sudden-onset severe headache, nausea, vomiting, and neck pain for the past 90 minutes. She describes her headache as a ‘thunderclap’, followed quickly by severe neck pain and stiffness, nausea and vomiting. She denies any loss of consciousness, seizure, or similar symptoms in the past. Her past medical history is significant for an episode 6 months ago where she suddenly had trouble putting weight on her right leg, which resolved within hours. The patient denies any history of smoking, alcohol or recreational drug use. On physical examination, the patient has significant nuchal rigidity. Her muscle strength in the lower extremities is 4/5 on the right and 5/5 on the left. The remainder of the physical examination is unremarkable. A noncontrast CT scan of the head is normal. Which of the following is the next best step in the management of this patient?
Q714
A 72-year-old woman with hypertension comes to the physician because of swelling and pain in both legs for the past year. The symptoms are worse at night and improve in the morning. Current medications include losartan and metoprolol. Her temperature is 36°C (96.8°F), pulse is 67/min, and blood pressure is 142/88 mm Hg. Examination shows normal heart sounds; there is no jugular venous distention. Her abdomen is soft and the liver edge is not palpable. Examination of the lower extremities shows bilateral pitting edema and prominent superficial veins. The skin is warm and there is reddish-brown discoloration of both ankles. Laboratory studies show a normal serum creatinine and normal urinalysis. Which of the following is the most likely underlying cause of this patient's symptoms?
Q715
A 38-year-old woman presents with progressive muscle weakness. The patient says that symptoms onset a couple of weeks ago and have progressively worsened. She says she hasn’t been able to lift her arms to comb her hair the past few days. No significant past medical history and no current medications. Family history is significant for her mother with scleroderma and an aunt with systemic lupus erythematosus (SLE). On physical examination, strength is 2 out of 5 in the upper extremities bilaterally. There is an erythematous area, consisting of alternating hypopigmentation and hyperpigmentation with telangiectasias, present on the extensor surfaces of the arms, the upper chest, and the neck in a ‘V-shaped’ distribution. Additional findings are presented in the exhibit (see image). Laboratory tests are significant for a positive antinuclear antibody (ANA) and elevated creatinine phosphokinase. Which of the following is the most appropriate first-line treatment for this patient?
Q716
A 50-year-old morbidly obese woman presents to a primary care clinic for the first time. She states that her father recently died due to kidney failure and wants to make sure she is healthy. She works as an accountant, is not married or sexually active, and drinks alcohol occasionally. She currently does not take any medications. She does not know if she snores at night but frequently feels fatigued. She denies any headaches but reports occasional visual difficulties driving at night. She further denies any blood in her urine or increased urinary frequency. She does not engage in any fitness program. She has her period every 2 months with heavy flows. Her initial vital signs reveal that her blood pressure is 180/100 mmHg and heart rate is 70/min. Her body weight is 150 kg (330 lb). On physical exam, the patient has droopy eyelids, a thick neck with a large tongue, no murmurs or clicks on cardiac auscultation, clear lungs, a soft nontender, albeit large abdomen, and palpable pulses in her distal extremities. She can walk without difficulty. A repeat measurement of her blood pressure shows 155/105 mmHg. Which among the following is part of the most appropriate next step in management?
Q717
A 32-year-old woman comes to the physician because of a 4-day history of low-grade fever, joint pain, and muscle aches. The day before the onset of her symptoms, she was severely sunburned on her face and arms during a hike with friends. She also reports being unusually fatigued over the past 3 months. Her only medication is a combined oral contraceptive pill. Her temperature is 37.9°C (100.2°F). Examination shows bilateral swelling and tenderness of the wrists and metacarpophalangeal joints. There are multiple nontender superficial ulcers on the oral mucosa. The detection of antibodies directed against which of the following is most specific for this patient's condition?
Q718
A 67-year-old woman comes to the physician because of intermittent chest pain and dizziness on exertion for 6 months. Her pulse is 76/min and blood pressure is 125/82 mm Hg. Cardiac examination shows a grade 3/6, late-peaking, crescendo-decrescendo murmur heard best at the right upper sternal border. An echocardiogram confirms the diagnosis. Three months later, the patient returns to the physician with worsening shortness of breath for 2 weeks. An ECG is shown. Which of the following changes is most likely responsible for this patient's acute exacerbation of symptoms?
Q719
A 67-year-old man presents to his primary care physician complaining of frequent urination overnight. He states that for several years he has had trouble maintaining his urine stream along with the need for frequent urination, but the nighttime urination has only recently started. The patient also states that he has had 2 urinary tract infections in the last year, which he had never had previously. On exam, his temperature is 98.8°F (37.1°C), blood pressure is 124/68 mmHg, pulse is 58/min, and respirations are 13/min. On digital rectal exam, the prostate is enlarged but feels symmetric and smooth. Which of the following is a possible consequence of this condition?
Q720
A 49-year-old male presents with a primary complaint of several recent episodes of severe headache, sudden anxiety, and a "racing heart". The patient originally attributed these symptoms to stress at work; however, these episodes are becoming more frequent and severe. Laboratory evaluation during such an episode reveals elevated plasma free metanephrines. Which of the following additional findings in this patient is most likely?
Cardiology US Medical PG Practice Questions and MCQs
Question 711: Three days after undergoing open surgery to repair a bilateral inguinal hernia, a 66-year-old man has new, intermittent upper abdominal discomfort that worsens when he walks around. He also has new shortness of breath that resolves with rest. There were no complications during surgery or during the immediate postsurgical period. Ambulation was restarted on the first postoperative day. He has type 2 diabetes mellitus, hypercholesterolemia, and hypertension. He has smoked one pack of cigarettes daily for 25 years. Prior to admission, his medications included metformin, simvastatin, and lisinopril. His temperature is 37°C (98.6°F), pulse is 80/min, respirations are 16/min, and blood pressure is 129/80 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. The abdomen is soft and shows two healing surgical scars with moderate serous discharge. Cardiopulmonary examination shows no abnormalities. An ECG at rest shows no abnormalities. Cardiac enzyme levels are within the reference range. An x-ray of the chest and abdominal ultrasonography show no abnormalities. Which of the following is the most appropriate next step in diagnosis?
A. Culture swab from the surgical site
B. Cardiac pharmacological stress test (Correct Answer)
C. Magnetic resonance imaging of the abdomen
D. Obtain serum D-dimer level
E. Coronary angiography
Explanation: ***Cardiac pharmacological stress test***
- The patient's symptoms of **intermittent upper abdominal discomfort** during activity and **shortness of breath** that improves with rest are highly suggestive of **angina equivalent**, especially given his multiple cardiovascular risk factors (type 2 diabetes, hypercholesterolemia, hypertension, and 25 pack-year smoking history).
- A **pharmacological stress test** is appropriate to uncover **demand ischemia** in a patient with normal resting ECG and cardiac enzymes.
- The patient cannot perform an exercise stress test shortly after abdominal surgery, making pharmacological stress testing the preferred non-invasive approach.
*Culture swab from the surgical site*
- While there is **serous discharge** from the surgical site, the patient's primary symptoms are systemic (new upper abdominal discomfort, shortness of breath) and are not typical of a localized surgical site infection, which would usually present with pain, erythema, and purulent discharge.
- A surgical site infection would not explain the **activity-related symptoms** that resolve with rest.
*Magnetic resonance imaging of the abdomen*
- Abdominal MRI is not indicated as the initial step for these symptoms. His abdominal discomfort is activity-related and associated with shortness of breath, pointing away from a primary intra-abdominal issue.
- **Abdominal ultrasonography** was already performed and was unremarkable, making further abdominal imaging unlikely to yield a diagnosis.
*Obtain serum D-dimer level*
- While **postoperative patients** are at risk for **venous thromboembolism (VTE)**, the symptoms of activity-related chest discomfort (angina equivalent) and shortness of breath are not classic for pulmonary embolism, especially with **98% oxygen saturation** and no tachycardia or respiratory distress.
- A D-dimer would require further imaging (CT pulmonary angiography) if elevated, but the clinical picture points more strongly to cardiac ischemia.
*Coronary angiography*
- **Coronary angiography** is an invasive procedure and should not be the initial diagnostic step.
- It is typically reserved for patients with a high pretest probability of **coronary artery disease** after non-invasive tests (such as a stress test) have indicated ischemia or for acute coronary syndromes.
- Performing a stress test first is a safer and more appropriate initial approach to confirm or rule out ischemia.
Question 712: A 35-year-old woman who was recently ill with an upper respiratory infection presents to the emergency department with weakness in her lower limbs and difficulty breathing. Her symptoms began with a burning sensation in her toes along with numbness. She claims that the weakness has been getting worse over the last few days and now involving her arms and face. Currently, she is unable to get up from the chair without some assistance. Her temperature is 37.0°C (98.6°F), the blood pressure is 145/89 mm Hg, the heart rate is 99/min, the respiratory rate is 12/min, and the oxygen saturation is 95% on room air. On physical examination, she has diminished breath sounds on auscultation of bilateral lung fields with noticeably poor inspiratory effort. Palpation of the lower abdomen reveals a palpable bladder. Strength is 3 out of 5 symmetrically in the lower extremities bilaterally. The sensation is intact. What is the most likely diagnosis?
A. Guillain-Barré syndrome (Correct Answer)
B. Adrenoleukodystrophy
C. Myasthenia Gravis
D. Multiple sclerosis
E. Acute disseminated encephalomyelitis
Explanation: ***Guillain-Barré syndrome***
- The patient presents with **ascending paralysis** (weakness starting in lower limbs and progressing upwards to arms and face) following an **upper respiratory infection**, which is a classic presentation of GBS.
- The presence of **respiratory compromise** (difficulty breathing, diminished breath sounds, poor inspiratory effort), **dysautonomia** (palpable bladder due to urinary retention), and the pattern of **symmetrical weakness with intact sensation** are characteristic features of GBS.
- GBS typically presents with areflexia and shows albumino-cytologic dissociation on CSF analysis (elevated protein with normal cell count).
*Adrenoleukodystrophy*
- This is a rare, **X-linked genetic disorder** that primarily affects white matter in the brain and spinal cord, typically presenting in childhood with neurological deficits, not an acute ascending paralysis after an infection.
- It involves demyelination and adrenal insufficiency, which are not suggested by the acute onset and progressive neurological symptoms described.
*Myasthenia Gravis*
- Myasthenia gravis typically presents with **fluctuating muscle weakness** that worsens with activity and improves with rest, often affecting ocular and bulbar muscles first.
- The progression of weakness in this case is constant and ascending, not fluctuating, and there is no mention of characteristic findings like ptosis or diplopia.
*Multiple sclerosis*
- MS is characterized by **demyelinating lesions** in the central nervous system, leading to neurological symptoms that are often **disseminated in space and time**, meaning they affect different parts of the body at different times.
- While it can cause weakness, the acute onset of rapidly progressive, ascending, symmetrical paralysis following an infection is not typical for MS; MS symptoms are usually more insidious or relapsing-remitting.
*Acute disseminated encephalomyelitis*
- ADEM is an **acute inflammatory demyelinating disease** of the central nervous system that typically follows an infection or vaccination, but it usually presents with **encephalopathy** (altered mental status), multifocal neurological deficits, and often affects the brain and spinal cord diffusely.
- While it can cause weakness, the prominent ascending paralysis, intact sensation, and lack of encephalopathy make GBS a more fitting diagnosis.
Question 713: A 56-year-old woman presents with sudden-onset severe headache, nausea, vomiting, and neck pain for the past 90 minutes. She describes her headache as a ‘thunderclap’, followed quickly by severe neck pain and stiffness, nausea and vomiting. She denies any loss of consciousness, seizure, or similar symptoms in the past. Her past medical history is significant for an episode 6 months ago where she suddenly had trouble putting weight on her right leg, which resolved within hours. The patient denies any history of smoking, alcohol or recreational drug use. On physical examination, the patient has significant nuchal rigidity. Her muscle strength in the lower extremities is 4/5 on the right and 5/5 on the left. The remainder of the physical examination is unremarkable. A noncontrast CT scan of the head is normal. Which of the following is the next best step in the management of this patient?
A. Diffusion-weighted magnetic resonance imaging of the brain
B. IV tPA
C. Placement of a ventriculoperitoneal (VP) shunt
D. T1/T2 MRI of the head
E. Lumbar puncture (Correct Answer)
Explanation: ***Lumbar puncture***
- A **thunderclap headache**, nuchal rigidity, nausea, and vomiting despite a normal noncontrast CT scan, is highly suspicious for **subarachnoid hemorrhage (SAH)**. A lumbar puncture is the next diagnostic step to look for **xanthochromia** or **red blood cells** in the cerebrospinal fluid.
- The previous episode of transient leg weakness could indicate a prior **warning leak** from an **aneurysm**, increasing the suspicion for SAH.
*Diffusion-weighted magnetic resonance imaging of the brain*
- This imaging is primarily used to detect **acute ischemic stroke**, which presents differently.
- While helpful for ischemic events, it is **not the primary diagnostic test** for suspected SAH after a normal CT.
*IV tPA*
- **Intravenous tissue plasminogen activator (IV tPA)** is a thrombolytic used in acute ischemic stroke, characterized by focal neurological deficits.
- It is **contraindicated** in SAH due to the significant risk of exacerbating intracranial bleeding.
*Placement of a ventriculoperitoneal (VP) shunt*
- A **VP shunt** is a surgical procedure to drain excess cerebrospinal fluid, typically used to treat **hydrocephalus**.
- This is a treatment for a complication (hydrocephalus) that may arise from SAH, but it is **not the initial diagnostic or management step** for an acute SAH.
*T1/T2 MRI of the head*
- While MRI can detect SAH, especially if performed with specific sequences (FLAIR), a **lumbar puncture is more sensitive for detecting SAH** when a CT scan is negative and clinical suspicion remains high.
- MRI is generally less accessible and more time-consuming than lumbar puncture in an emergency setting for suspected SAH.
Question 714: A 72-year-old woman with hypertension comes to the physician because of swelling and pain in both legs for the past year. The symptoms are worse at night and improve in the morning. Current medications include losartan and metoprolol. Her temperature is 36°C (96.8°F), pulse is 67/min, and blood pressure is 142/88 mm Hg. Examination shows normal heart sounds; there is no jugular venous distention. Her abdomen is soft and the liver edge is not palpable. Examination of the lower extremities shows bilateral pitting edema and prominent superficial veins. The skin is warm and there is reddish-brown discoloration of both ankles. Laboratory studies show a normal serum creatinine and normal urinalysis. Which of the following is the most likely underlying cause of this patient's symptoms?
A. Decreased arteriolar resistance
B. Increased venous valve reflux (Correct Answer)
C. Decreased intravascular oncotic pressure
D. Decreased lymphatic flow
E. Increased capillary permeability
Explanation: ***Increased venous valve reflux***
- The patient presents with **bilateral pitting edema**, **prominent superficial veins**, and **reddish-brown discoloration of the ankles**, which are classic signs of **chronic venous insufficiency**.
- **Venous valve reflux** leads to increased hydrostatic pressure in the capillaries, causing fluid transudation into the interstitial space, leading to edema that is worse at night and improves with elevation.
*Decreased arteriolar resistance*
- **Decreased arteriolar resistance** can lead to increased blood flow to the capillaries, but it typically causes edema that is **warm and erythematous**, often in the context of inflammation or certain medications (e.g., dihydropyridine calcium channel blockers), which is not the primary mechanism here.
- While some medications can cause edema, the full clinical picture points more specifically to venous stasis.
*Decreased intravascular oncotic pressure*
- **Decreased intravascular oncotic pressure** (e.g., due to low albumin from liver disease or nephrotic syndrome) causes **generalized edema** that is often symmetrical, but it would not typically cause prominent superficial veins or reddish-brown ankle discoloration.
- The patient's normal liver exam and creatinine/urinalysis make this less likely.
*Decreased lymphatic flow*
- **Decreased lymphatic flow** results in **lymphedema**, which is typically **non-pitting**, unilateral, and does not cause prominent superficial veins or pigment changes initially.
- Lymphedema often leads to a "woody" texture and can be associated with skin thickening over time.
*Increased capillary permeability*
- **Increased capillary permeability** can cause edema, often due to **inflammation**, allergic reactions, or sepsis, and typically presents with warmth, erythema, and localized swelling.
- This mechanism is usually acute and does not primarily explain the chronic skin changes and prominent veins seen in this patient.
Question 715: A 38-year-old woman presents with progressive muscle weakness. The patient says that symptoms onset a couple of weeks ago and have progressively worsened. She says she hasn’t been able to lift her arms to comb her hair the past few days. No significant past medical history and no current medications. Family history is significant for her mother with scleroderma and an aunt with systemic lupus erythematosus (SLE). On physical examination, strength is 2 out of 5 in the upper extremities bilaterally. There is an erythematous area, consisting of alternating hypopigmentation and hyperpigmentation with telangiectasias, present on the extensor surfaces of the arms, the upper chest, and the neck in a ‘V-shaped’ distribution. Additional findings are presented in the exhibit (see image). Laboratory tests are significant for a positive antinuclear antibody (ANA) and elevated creatinine phosphokinase. Which of the following is the most appropriate first-line treatment for this patient?
A. Methotrexate
B. Hydroxychloroquine
C. High-dose corticosteroids (Correct Answer)
D. Infliximab
E. Intravenous immunoglobulin
Explanation: ***High-dose corticosteroids***
- This patient presents with **proximal muscle weakness**, characteristic skin findings (**heliotrope rash** and **Gottron papules** based on the image exhibit), elevated **creatinine phosphokinase**, and positive **ANA**, which are highly suggestive of **dermatomyositis**.
- **High-dose corticosteroids** are the cornerstone of initial treatment for dermatomyositis due to their potent anti-inflammatory and immunosuppressive effects, rapidly controlling disease activity and improving muscle strength.
*Methotrexate*
- **Methotrexate** is an immunosuppressant often used as a **second-line agent** or in combination with corticosteroids for dermatomyositis, especially in patients who do not respond adequately to steroids alone or require steroid-sparing agents.
- It works more slowly than corticosteroids and is not typically used for initial acute management of severe symptoms due to its delayed onset of action.
*Hydroxychloroquine*
- **Hydroxychloroquine** is primarily used for the skin manifestations of dermatomyositis or lupus, and is not sufficiently potent to treat the muscle weakness or systemic involvement characteristic of active dermatomyositis.
- It would be considered for **mild cutaneous disease** or as an adjunct, but not as the initial first-line treatment for multiorgan involvement.
*Infliximab*
- **Infliximab** is a **TNF-alpha inhibitor** used in conditions like rheumatoid arthritis, psoriasis, and inflammatory bowel disease. It is **not indicated** for dermatomyositis.
- TNF-alpha inhibitors are generally not used in the management of idiopathic inflammatory myopathies, and there is no evidence to support its role as a first-line treatment for dermatomyositis.
*Intravenous immunoglobulin*
- **Intravenous immunoglobulin (IVIG)** is a treatment option for **refractory dermatomyositis**, or in cases of severe, life-threatening disease not responding to corticosteroids and other immunosuppressants.
- While effective, it is not considered first-line due to its cost, potential side effects, and the need for immediate, potent immunosuppression provided by corticosteroids.
Question 716: A 50-year-old morbidly obese woman presents to a primary care clinic for the first time. She states that her father recently died due to kidney failure and wants to make sure she is healthy. She works as an accountant, is not married or sexually active, and drinks alcohol occasionally. She currently does not take any medications. She does not know if she snores at night but frequently feels fatigued. She denies any headaches but reports occasional visual difficulties driving at night. She further denies any blood in her urine or increased urinary frequency. She does not engage in any fitness program. She has her period every 2 months with heavy flows. Her initial vital signs reveal that her blood pressure is 180/100 mmHg and heart rate is 70/min. Her body weight is 150 kg (330 lb). On physical exam, the patient has droopy eyelids, a thick neck with a large tongue, no murmurs or clicks on cardiac auscultation, clear lungs, a soft nontender, albeit large abdomen, and palpable pulses in her distal extremities. She can walk without difficulty. A repeat measurement of her blood pressure shows 155/105 mmHg. Which among the following is part of the most appropriate next step in management?
A. Renal artery doppler ultrasonography
B. Polysomnography
C. Urinalysis (Correct Answer)
D. Thyroid-stimulating hormone
E. Cortisol levels
Explanation: ***Urinalysis***
- Given the patient's strong family history of **kidney failure**, current presentation with **hypertension (BP 180/100 mmHg, confirmed at 155/105 mmHg)**, and concern for her health, a urinalysis is a crucial initial step to look for signs of kidney damage or disease.
- Urinalysis can detect **proteinuria**, **hematuria**, or other abnormalities indicative of renal pathology, helping to assess her kidney health.
*Renal artery doppler ultrasonography*
- While **renal artery stenosis** can cause hypertension, it is usually considered after initial non-invasive tests and if there are specific signs of secondary hypertension like a **renal bruit** or **unexplained renal insufficiency**, which are not explicitly described here as a first step.
- This is a more advanced diagnostic test and not typically the *most appropriate next step* before basic screening like urinalysis.
*Polysomnography*
- The patient's **morbid obesity**, **fatigue**, and physical exam findings like a **thick neck with a large tongue** suggest **obstructive sleep apnea (OSA)**, for which polysomnography is the diagnostic test.
- However, while important, addressing the immediate concern of **hypertension** and assessing **kidney health** (given the family history) is a higher priority in the *initial* workup.
*Thyroid-stimulating hormone*
- Symptoms like **fatigue**, **heavy menstrual periods (menorrhagia)**, and features like a **thick tongue** could suggest **hypothyroidism**.
- However, **hypertension** and the urgent need to evaluate **kidney function** (due to family history and current high blood pressure) make urinalysis a more immediate and critical step before an extensive endocrine workup.
*Cortisol levels*
- Elevated blood pressure, obesity, and menstrual irregularities could, in some contexts, raise suspicion for **Cushing's syndrome**.
- However, there are no classic features like **buffalo hump**, **moon facies**, or **striae** mentioned, and assessing renal involvement given the family history and current hypertension is a more direct next step.
Question 717: A 32-year-old woman comes to the physician because of a 4-day history of low-grade fever, joint pain, and muscle aches. The day before the onset of her symptoms, she was severely sunburned on her face and arms during a hike with friends. She also reports being unusually fatigued over the past 3 months. Her only medication is a combined oral contraceptive pill. Her temperature is 37.9°C (100.2°F). Examination shows bilateral swelling and tenderness of the wrists and metacarpophalangeal joints. There are multiple nontender superficial ulcers on the oral mucosa. The detection of antibodies directed against which of the following is most specific for this patient's condition?
A. Nuclear Sm proteins (Correct Answer)
B. Fc region of IgG
C. Single-stranded DNA
D. Cell nucleus
E. Histones
Explanation: ***Nuclear Sm proteins***
- Antibodies to **Sm proteins** (anti-Sm antibodies) are highly specific for **Systemic Lupus Erythematosus (SLE)**, although present in only a minority of patients.
- The patient's symptoms, including **photosensitivity (exacerbation by sunburn)**, **arthritis**, **oral ulcers**, and **fatigue**, are classic manifestations of SLE.
*Fc region of IgG*
- Antibodies directed against the **Fc region of IgG** are known as **rheumatoid factor (RF)**.
- While RF can be positive in a small percentage of SLE patients, it is most characteristic of **rheumatoid arthritis** and is not specific for SLE.
*Single-stranded DNA*
- Antibodies to **single-stranded DNA (anti-ssDNA antibodies)** are found in various autoimmune diseases, including SLE, but are **less specific** than anti-dsDNA or anti-Sm antibodies for SLE diagnosis.
- These antibodies can also be seen in drug-induced lupus and other conditions, making them a less definitive marker.
*Cell nucleus*
- Antibodies directed against the **cell nucleus** (antinuclear antibodies or **ANA**) are present in nearly all patients with SLE and are highly sensitive for the disease.
- However, ANA can also be positive in many other autoimmune conditions, infections, and even healthy individuals, making it **not specific** enough for a definitive diagnosis without other criteria.
*Histones*
- Antibodies to **histones** are most commonly associated with **drug-induced lupus erythematosus**.
- While they can be present in some cases of SLE, the patient's presentation does not strongly suggest drug-induced lupus, and anti-histone antibodies are not the most specific marker for typical SLE.
Question 718: A 67-year-old woman comes to the physician because of intermittent chest pain and dizziness on exertion for 6 months. Her pulse is 76/min and blood pressure is 125/82 mm Hg. Cardiac examination shows a grade 3/6, late-peaking, crescendo-decrescendo murmur heard best at the right upper sternal border. An echocardiogram confirms the diagnosis. Three months later, the patient returns to the physician with worsening shortness of breath for 2 weeks. An ECG is shown. Which of the following changes is most likely responsible for this patient's acute exacerbation of symptoms?
A. Impaired pulmonary artery outflow
B. Increased systemic vascular resistance
C. Decreased left ventricular preload (Correct Answer)
D. Impaired contractility of the left ventricle
E. Decreased impulse conduction across the AV node
Explanation: ***Decreased left ventricular preload***
- The ECG shows **atrial fibrillation** (irregularly irregular rhythm, absence of P waves), which significantly reduces **atrial kick**.
- In a patient with **aortic stenosis** (suggested by the murmur and symptoms), maintaining adequate left ventricular preload is crucial, and its reduction due to atrial fibrillation can acutely worsen symptoms by decreasing cardiac output.
*Impaired pulmonary artery outflow*
- This condition, typically seen in **pulmonary hypertension** or **pulmonic stenosis**, primarily affects the right side of the heart.
- The patient's presentation with a murmur heard best at the **right upper sternal border** and systemic symptoms points towards left-sided heart disease, specifically aortic stenosis.
*Increased systemic vascular resistance*
- While increased afterload can exacerbate heart failure, the primary issue suggested by the ECG (atrial fibrillation) specifically impacts **preload** rather than systemic vascular resistance directly.
- There is no information provided that would indicate an acute increase in afterload.
*Impaired contractility of the left ventricle*
- While impaired contractility can lead to shortness of breath, the acute change shown in the ECG is **atrial fibrillation**, which primarily affects **diastolic filling** (preload) rather than the contractile function of the ventricle itself.
- Aortic stenosis primarily causes **pressure overload**, leading to concentric hypertrophy, and contractility may be preserved initially.
*Decreased impulse conduction across the AV node*
- This would result in a slower heart rate (e.g., **bradycardia** or **heart block**), not the irregularly irregular rhythm characteristic of atrial fibrillation.
- Atrial fibrillation in fact involves rapid and chaotic atrial activity with variable AV nodal conduction, leading to a rapid, irregular ventricular response.
Question 719: A 67-year-old man presents to his primary care physician complaining of frequent urination overnight. He states that for several years he has had trouble maintaining his urine stream along with the need for frequent urination, but the nighttime urination has only recently started. The patient also states that he has had 2 urinary tract infections in the last year, which he had never had previously. On exam, his temperature is 98.8°F (37.1°C), blood pressure is 124/68 mmHg, pulse is 58/min, and respirations are 13/min. On digital rectal exam, the prostate is enlarged but feels symmetric and smooth. Which of the following is a possible consequence of this condition?
A. Increased serum creatinine (Correct Answer)
B. Malignant transformation
C. Increased serum AFP
D. Increased serum hCG
E. Increased serum ALP
Explanation: ***Increased serum creatinine***
- Chronic **urinary retention** due to benign prostatic hyperplasia (BPH) can lead to **hydronephrosis** and **renal parenchymal damage**, impairing kidney function and increasing serum creatinine.
- The patient's symptoms of difficulty maintaining urine stream, frequent urination, and recurrent UTIs suggest BPH, which can progress to urinary obstruction and subsequent kidney dysfunction.
*Malignant transformation*
- **Benign prostatic hyperplasia (BPH)** is a non-malignant condition and does not directly undergo **malignant transformation** into prostate cancer.
- While both BPH and prostate cancer can coexist, BPH itself is not considered a premalignant lesion.
*Increased serum AFP*
- **Alpha-fetoprotein (AFP)** is a tumor marker primarily associated with **hepatocellular carcinoma** and **germ cell tumors** (e.g., testicular cancer).
- It is not associated with benign prostatic hyperplasia (BPH) or its complications.
*Increased serum hCG*
- **Human chorionic gonadotropin (hCG)** is a tumor marker most notably elevated in **choriocarcinoma** and some **germ cell tumors**.
- It has no association with benign prostatic hyperplasia (BPH) or urinary obstruction.
*Increased serum ALP*
- **Alkaline phosphatase (ALP)** can be elevated in conditions affecting the **liver** (e.g., cholestasis) or **bones** (e.g., Paget's disease, osteoblastic metastases).
- While significantly elevated ALP can indicate prostate cancer with **bone metastases**, it is not a direct consequence of uncomplicated benign prostatic hyperplasia (BPH).
Question 720: A 49-year-old male presents with a primary complaint of several recent episodes of severe headache, sudden anxiety, and a "racing heart". The patient originally attributed these symptoms to stress at work; however, these episodes are becoming more frequent and severe. Laboratory evaluation during such an episode reveals elevated plasma free metanephrines. Which of the following additional findings in this patient is most likely?
A. Anhidrosis
B. Diarrhea
C. Episodic hypertension (Correct Answer)
D. Hypoglycemia
E. Decreased 24 hour urine vanillylmandelic acid (VMA) levels
Explanation: ***Episodic hypertension***
- The patient's symptoms of severe headache, sudden anxiety, a "racing heart," and **elevated plasma free metanephrines** are classic presentations of a **pheochromocytoma**, a tumor that produces catecholamines. These catecholamines cause **paroxysmal (episodic) hypertension**.
- **Hypertensive episodes** are a hallmark symptom of pheochromocytoma, often triggered by stress, exercise, or changes in body position.
*Anhidrosis*
- **Anhidrosis** (lack of sweating) is not a typical manifestation of pheochromocytoma; rather, patients often experience **diaphoresis (excessive sweating)** due to overstimulation of adrenergic receptors.
- Anhidrosis can be a feature of certain neuropathies or autonomic dysfunction, but it does not align with the hyperadrenergic state described.
*Diarrhea*
- While pheochromocytoma can cause gastrointestinal symptoms due to altered autonomic tone, **diarrhea** is uncommon; **constipation** is more frequently reported because of catecholamine effects on gut motility.
- Diarrhea is more commonly associated with conditions like carcinoid syndrome or irritable bowel syndrome.
*Hypoglycemia*
- **Hypoglycemia** is generally not associated with pheochromocytoma; the excess catecholamines typically promote **glycogenolysis and gluconeogenesis**, leading to **hyperglycemia**.
- Hypoglycemia could be caused by an insulinoma or certain endocrine deficiencies.
*Decreased 24 hour urine vanillylmandelic acid (VMA) levels*
- **Elevated plasma free metanephrines** indicate excessive catecholamine production, which would lead to **elevated 24-hour urine VMA** (a catecholamine metabolite), not decreased levels.
- Decreased VMA levels would suggest conditions with reduced catecholamine production, which contradicts the clinical picture of hyperadrenergic symptoms.