A 22-year-old man presents with lower limb weakness for the past 2 days. The patient says that the weakness started in both his feet, manifesting as difficulty walking, but it has progressed to where he cannot move his legs completely and has become bedbound. He also has experienced a recent history of numbness and tingling sensations in both his feet. He denies any recent history of fever, backache, urinary or bowel incontinence, trauma, shortness of breath, or diplopia. His past medical history is remarkable for a viral flu-like illness 2 weeks ago. The patient is afebrile, and his vital signs are within normal limits. On physical examination, muscle strength in both lower limbs is 1/5. The muscle strength in the upper limbs is ⅘ bilaterally. Sensation to pinprick is decreased in both lower limbs in a stocking distribution. The sensation is intact in the upper limbs bilaterally. Knee and ankle reflexes are absent bilaterally. The laboratory findings are significant for the following:
Hemoglobin 14.2 g/dL
White blood cell count 8,250/mm3
Platelet count 258,000/mm3
BUN 14 mg/dL
Creatinine 0.9 mg/dL
Serum sodium 144 mEq/L
Serum potassium 3.9 mEq/L
Which of the following tests would most likely confirm the diagnosis in this patient?
Q392
A 62-year-old man comes to the physician for decreased exercise tolerance. Over the past four months, he has noticed progressively worsening shortness of breath while walking his dog. He also becomes short of breath when lying in bed at night. His temperature is 36.4°C (97.5°F), pulse is 82/min, respirations are 19/min, and blood pressure is 155/53 mm Hg. Cardiac examination shows a high-pitch, decrescendo murmur that occurs immediately after S2 and is heard best along the left sternal border. There is an S3 gallop. Carotid pulses are strong. Which of the following is the most likely diagnosis?
Q393
A 65-year-old man presented to the hospital with a history of repeated falls, postural dizziness, progressive fatigue, generalized weakness, and a 13.6 kg (30 lb) weight loss over a duration of 6 months. He is a vegetarian. His family members complain of significant behavioral changes over the past year. The patient denies smoking, alcohol consumption, or illicit drug use. There is no significant family history of any illness. Initial examination reveals a pale, thin built man. He is irritable, paranoid, delusional, but denies any hallucinations. The blood pressure is 100/60 mm Hg, heart rate is 92/min, respiratory rate is 16/min, and the temperature is 36.1℃ (97℉). He has an unstable, wide-based ataxic gait. The anti-intrinsic factor antibodies test is positive. The laboratory test results are as follows:
Hb 6.1gm/dL
MCV 99 fL
Platelets 900,000/mm3
Total WBC count 3,000/mm3
Reticulocyte 0.8%
The peripheral blood smear is shown in the image below. What is the most likely cause of his condition?
Q394
A 38-year-old female presents to the emergency room with fevers, fatigue, and anorexia for over a month. Past medical history includes mild mitral valve prolapse. She underwent an uncomplicated tooth extraction approximately 6 weeks ago. Her vital signs include a temperature of 100.8 F, pulse of 83, blood pressure of 110/77, and SpO2 of 97% on room air. On exam, you note a grade III/VI holosystolic murmur at the apex radiating to the axilla as well as several red, painful nodules on her fingers. Which of the following is the next best course of action?
Q395
A 45-year-old woman comes to the physician for a 3-week history of intermittent episodes of dizziness. The episodes last for hours at a time and are characterized by the sensation that the room is spinning. The patient also reports that she has started using her cell phone with her left ear because she hears better on that side. She has experienced intermittent ringing and fullness in her right ear. She has no history of serious medical conditions. She does not smoke or drink alcohol. She takes no medications. Her temperature is 37.1°C (98.8°F) pulse is 76/min respirations are 18/min, and blood pressure is 130/76 mm Hg. Cardiopulmonary examination shows no abnormalities. There is horizontal nystagmus to the right. Motor strength is 5/5 in all extremities, and sensory examination shows no abnormalities. Finger-to-nose and heel-to-shin testing are normal bilaterally. Weber test shows lateralization to the left ear. The Rinne test is positive bilaterally. Which of the following is the most likely cause of this patient's symptoms?
Q396
A 21-year-old African American woman presents with difficulty breathing, chest pain, and a non-productive cough. She says she took some ibuprofen earlier but it did not improve her pain. Past medical history is significant for sickle cell disease. Medications include hydroxyurea, iron, vitamin B12, and an oral contraceptive pill. She says she received a blood transfusion 6 months ago to reduce her Hgb S below 30%. Her vital signs include: temperature 38.2°C (100.7°F), blood pressure 112/71 mm Hg, pulse 105/min, oxygen saturation 91% on room air. A chest radiograph is performed and is shown in the exhibit. Which of the following is best initial step in the management of this patient's condition?
Q397
A 63-year-old woman presents to your outpatient clinic complaining of headaches, blurred vision, and fatigue. She has a blood pressure of 171/91 mm Hg and heart rate of 84/min. Physical examination is unremarkable. Her lab results include K+ of 3.1mEq/L and a serum pH of 7.51. Of the following, which is the most likely diagnosis for this patient?
Q398
A 26-year-old man presents with a 2-day history of worsening right lower leg pain. He states that he believes his right leg is swollen when compared to his left leg. Past medical history is significant for generalized anxiety disorder, managed effectively with psychotherapy. He smokes a pack of cigarettes daily but denies alcohol and illicit drug use. His father died of a pulmonary embolism at the age of 43. His vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, respiratory rate 14/min. On physical examination, the right lower leg is warmer than the left, and dorsiflexion of the right foot produces pain. Which of the following conditions is most likely responsible for this patient’s presentation?
Q399
A 70-year-old man presents with a complaint of progressive dyspnea on minimal exertion. The patient reports being quite active and able to climb 3 flights of stairs in his building 10 years ago, whereas now he feels extremely winded when climbing a single flight. At first, he attributed this to old age but has more recently begun noticing that he feels similarly short of breath when lying down. He denies any recent fevers, cough, chest pain, nausea, vomiting, or diarrhea. He denies any past medical history except for two hospitalizations over the past 10 years for "the shakes." Family history is negative for any heart conditions. Social history is significant for a 10 pack-year smoking history. He currently drinks "a few" drinks per night. On exam, his vitals are: BP 120/80, HR 85, RR 14, and SpO2 97%. He is a mildly obese man who appears his stated age. Physical exam is significant for a normal heart exam with a few crackles heard at the bases of both lungs. Abdominal exam is significant for an obese abdomen and a liver edge palpated 2-3 cm below the costal margin. He has 2+ edema present in both lower extremities. Lab results reveal a metabolic panel significant for a sodium of 130 mEq/L but otherwise normal. Complete blood count, liver function tests, and coagulation studies are normal as well. An EKG reveals signs of left ventricular enlargement with a first degree AV block. A cardiac catheterization report from 5 years ago reveals a moderately enlarged heart but patent coronary arteries. Which of the following is the most likely cause of this individual's symptoms?
Q400
A 61-year-old man comes to the physician because of a 3-month history of fatigue and progressively worsening shortness of breath that is worse when lying down. Recently, he started using two pillows to avoid waking up short of breath at night. Examination shows a heart murmur. A graph with the results of cardiac catheterization is shown. Given this patient's valvular condition, which of the following murmurs is most likely to be heard on cardiac auscultation?
Cardiology US Medical PG Practice Questions and MCQs
Question 391: A 22-year-old man presents with lower limb weakness for the past 2 days. The patient says that the weakness started in both his feet, manifesting as difficulty walking, but it has progressed to where he cannot move his legs completely and has become bedbound. He also has experienced a recent history of numbness and tingling sensations in both his feet. He denies any recent history of fever, backache, urinary or bowel incontinence, trauma, shortness of breath, or diplopia. His past medical history is remarkable for a viral flu-like illness 2 weeks ago. The patient is afebrile, and his vital signs are within normal limits. On physical examination, muscle strength in both lower limbs is 1/5. The muscle strength in the upper limbs is ⅘ bilaterally. Sensation to pinprick is decreased in both lower limbs in a stocking distribution. The sensation is intact in the upper limbs bilaterally. Knee and ankle reflexes are absent bilaterally. The laboratory findings are significant for the following:
Hemoglobin 14.2 g/dL
White blood cell count 8,250/mm3
Platelet count 258,000/mm3
BUN 14 mg/dL
Creatinine 0.9 mg/dL
Serum sodium 144 mEq/L
Serum potassium 3.9 mEq/L
Which of the following tests would most likely confirm the diagnosis in this patient?
A. Acetylcholine receptor antibodies
B. Muscle biopsy
C. Nerve conduction studies (Correct Answer)
D. Serum creatine kinase
E. MRI of the lumbosacral spine
Explanation: ***Nerve conduction studies***
- This patient presents with **progressive, ascending weakness** and **areflexia** following a recent viral illness, highly suggestive of **Guillain-Barré Syndrome (GBS)**. Nerve conduction studies (NCS) will show evidence of **demyelination** (e.g., prolonged distal latencies, reduced conduction velocities, conduction block) or axonal damage, which is characteristic of GBS.
- NCS are crucial for confirming the diagnosis of GBS by demonstrating the typical electrophysiological abnormalities in peripheral nerves.
*Acetylcholine receptor antibodies*
- **Acetylcholine receptor antibodies** are elevated in **myasthenia gravis**, an autoimmune disorder characterized by fluctuating muscle weakness that worsens with activity and improves with rest.
- The patient's symptoms of **progressive ascending paralysis** and **areflexia**, are inconsistent with myasthenia gravis, which typically presents with ocular, bulbar, or generalized weakness without prominent sensory deficits.
*Muscle biopsy*
- A **muscle biopsy** is generally used to diagnose **myopathies** or muscular dystrophies, which would show characteristic muscle fiber degeneration or inflammatory changes.
- This patient's presentation with **ascending weakness**, **sensory changes**, and **areflexia** points towards a peripheral neuropathy rather than a primary muscle disorder.
*Serum creatine kinase*
- **Serum creatine kinase (CK)** levels are typically elevated in **muscle damage** or inflammatory myopathies.
- While GBS can rarely cause a mild elevation, it is not a primary diagnostic marker, and a normal CK level does not rule out the condition.
*MRI of the lumbosacral spine*
- An **MRI of the lumbosacral spine** would be indicated if **spinal cord compression** or other spinal pathology were suspected, such as in cases of significant back pain, bladder/bowel dysfunction, or a distinct sensory level.
- The patient's presentation of **ascending weakness**, **symmetrical sensory deficits in a stocking distribution**, and **areflexia** without signs of spinal cord compression makes spinal MRI less likely to be the diagnostic test for the presenting illness.
Question 392: A 62-year-old man comes to the physician for decreased exercise tolerance. Over the past four months, he has noticed progressively worsening shortness of breath while walking his dog. He also becomes short of breath when lying in bed at night. His temperature is 36.4°C (97.5°F), pulse is 82/min, respirations are 19/min, and blood pressure is 155/53 mm Hg. Cardiac examination shows a high-pitch, decrescendo murmur that occurs immediately after S2 and is heard best along the left sternal border. There is an S3 gallop. Carotid pulses are strong. Which of the following is the most likely diagnosis?
A. Aortic valve regurgitation (Correct Answer)
B. Tricuspid valve regurgitation
C. Mitral valve prolapse
D. Mitral valve regurgitation
E. Mitral valve stenosis
Explanation: ***Aortic valve regurgitation***
- A **high-pitch, decrescendo murmur immediately after S2** and heard best along the **left sternal border** is characteristic of **aortic regurgitation**.
- Symptoms like **dyspnea on exertion** and **orthopnea**, an **S3 gallop**, and a **wide pulse pressure** (155/53 mmHg) further support heart failure due to chronic aortic regurgitation.
*Tricuspid valve regurgitation*
- This typically presents with a **holosystolic murmur** best heard at the **left lower sternal border** that increases with inspiration.
- Clinical signs often include **jugular venous distension** and **peripheral edema**, not primarily a decrescendo diastolic murmur.
*Mitral valve prolapse*
- Characterized by a **mid-systolic click** followed by a **late systolic murmur**, and symptomatically may be asymptomatic or cause palpitations.
- The described diastolic murmur and symptoms of heart failure do not align with mitral valve prolapse.
*Mitral valve regurgitation*
- Typically presents as a **holosystolic murmur** heard best at the **apex** and often radiating to the axilla.
- While it can cause dyspnea and an S3, the character and timing of the murmur reported (decrescendo, immediately after S2) are inconsistent with mitral regurgitation.
*Mitral valve stenosis*
- This condition presents with a **diastolic rumble** heard best at the **apex** with an opening snap.
- The murmur described is a high-pitch decrescendo murmur, which is distinct from the low-pitched rumble of mitral stenosis.
Question 393: A 65-year-old man presented to the hospital with a history of repeated falls, postural dizziness, progressive fatigue, generalized weakness, and a 13.6 kg (30 lb) weight loss over a duration of 6 months. He is a vegetarian. His family members complain of significant behavioral changes over the past year. The patient denies smoking, alcohol consumption, or illicit drug use. There is no significant family history of any illness. Initial examination reveals a pale, thin built man. He is irritable, paranoid, delusional, but denies any hallucinations. The blood pressure is 100/60 mm Hg, heart rate is 92/min, respiratory rate is 16/min, and the temperature is 36.1℃ (97℉). He has an unstable, wide-based ataxic gait. The anti-intrinsic factor antibodies test is positive. The laboratory test results are as follows:
Hb 6.1gm/dL
MCV 99 fL
Platelets 900,000/mm3
Total WBC count 3,000/mm3
Reticulocyte 0.8%
The peripheral blood smear is shown in the image below. What is the most likely cause of his condition?
A. Folate deficiency
B. Alcoholism
C. Parvovirus infection
D. Pernicious anemia (Correct Answer)
E. Hypothyroidism
Explanation: ***Pernicious anemia***
- The patient exhibits classic signs of **pernicious anemia**, including **macrocytic anemia** (MCV 99 fL), **bicytopenia** (Hb 6.1, WBC 3000) with **reactive thrombocytosis** (platelets 900,000), **neurological symptoms** (ataxic gait, falls, behavioral changes, paranoia, delusions), and a **positive anti-intrinsic factor antibody test**.
- **Vegetarian diet** is a significant risk factor due to inadequate intake of **vitamin B12**, which is crucial for DNA synthesis and red blood cell maturation.
- The **anti-intrinsic factor antibody** is highly specific for pernicious anemia, the autoimmune form of B12 deficiency.
*Folate deficiency*
- Folate deficiency presents with **macrocytic anemia** and can cause **glossitis**, similar to B12 deficiency.
- However, unlike B12 deficiency, it typically does not cause the severe **neurological and neuropsychiatric manifestations** seen in this patient (ataxia, paranoia, delusions), and **anti-intrinsic factor antibodies would be negative**.
*Alcoholism*
- Chronic alcoholism can lead to **macrocytic anemia**, often due to **folate deficiency** or direct toxic effects on bone marrow.
- While it can cause neurological deficits and psychiatric symptoms, the patient **denies alcohol consumption**, and the positive **anti-intrinsic factor antibody test** points away from primary alcoholism as the cause.
*Parvovirus infection*
- Parvovirus B19 typically causes **transient aplastic crisis** in individuals with underlying hemolytic disorders, leading to **severe anemia** and **reticulocytopenia**.
- It would not explain the **macrocytosis**, **neurological symptoms**, or **positive anti-intrinsic factor antibodies**.
*Hypothyroidism*
- Hypothyroidism can present with **fatigue**, **weakness**, and even some cognitive or psychiatric changes; however, it typically causes **normocytic** or **mild macrocytic anemia** and would not explain the **leukopenia** or **positive anti-intrinsic factor antibodies**.
- It also wouldn't account for the pronounced **ataxic gait** or **delusions**.
Question 394: A 38-year-old female presents to the emergency room with fevers, fatigue, and anorexia for over a month. Past medical history includes mild mitral valve prolapse. She underwent an uncomplicated tooth extraction approximately 6 weeks ago. Her vital signs include a temperature of 100.8 F, pulse of 83, blood pressure of 110/77, and SpO2 of 97% on room air. On exam, you note a grade III/VI holosystolic murmur at the apex radiating to the axilla as well as several red, painful nodules on her fingers. Which of the following is the next best course of action?
A. Blood cultures are not needed. Start empiric antibiotics
B. Start anticoagulation with heparin
C. Consult cardiothoracic surgery for mitral valve replacement
D. Obtain blood cultures x3 sites over 24 hours and start antibiotics after culture results are available
E. Obtain blood cultures x3 sites over 1 hour and start empiric antibiotics (Correct Answer)
Explanation: ***Obtain blood cultures x3 sites over 1 hour and start empiric antibiotics***
- The patient's presentation with **fever, fatigue, anorexia, new murmur, and painful finger nodules (Osler's nodes)** after a recent dental procedure strongly suggests **infective endocarditis**. Prompt initiation of **empiric antibiotics** after obtaining adequate blood cultures is crucial to improve outcomes and prevent further complications like septic emboli or valvular damage.
- Obtaining **multiple blood cultures rapidly (e.g., three sets over 1 hour)** from different sites maximizes the chance of isolating the causative organism before antibiotics are given, enabling targeted therapy later, while minimizing delay to treatment.
*Blood cultures are not needed. Start empiric antibiotics*
- **Blood cultures are essential** for diagnosing infective endocarditis, identifying the causative organism, and guiding appropriate antibiotic therapy. Skipping blood cultures could lead to inappropriate antibiotic selection and treatment failure.
- While empiric antibiotics are warranted, they should always be initiated **after blood cultures** have been drawn to avoid sterilizing the blood and making microbial identification difficult.
*Start anticoagulation with heparin*
- **Anticoagulation is generally contraindicated** in infective endocarditis due to the increased risk of hemorrhagic complications, especially in cases of septic emboli to the brain.
- While patients with endocarditis can form vegetations that may embolize, the risks of **bleeding outweigh the benefits** of routine anticoagulation.
*Consult cardiothoracic surgery for mitral valve replacement*
- While **mitral valve prolapse** is a risk factor for endocarditis and severe valvular damage may eventually require surgery, primary management involves **antibiotic therapy**.
- Surgical intervention is typically reserved for cases with **severe valvular regurgitation/stenosis leading to heart failure**, uncontrolled infection despite antibiotics, or recurrent emboli, and is not the immediate next step.
*Obtain blood cultures x3 sites over 24 hours and start antibiotics after culture results are available*
- Waiting for **24 hours to collect blood cultures** would significantly delay the initiation of antibiotics, which is dangerous in a potentially life-threatening infection like endocarditis.
- Delaying antibiotics until **culture results are available** could take several days, leading to worsening infection, organ damage, and increased mortality. **Empiric antibiotics** must be started promptly after initial blood collection.
Question 395: A 45-year-old woman comes to the physician for a 3-week history of intermittent episodes of dizziness. The episodes last for hours at a time and are characterized by the sensation that the room is spinning. The patient also reports that she has started using her cell phone with her left ear because she hears better on that side. She has experienced intermittent ringing and fullness in her right ear. She has no history of serious medical conditions. She does not smoke or drink alcohol. She takes no medications. Her temperature is 37.1°C (98.8°F) pulse is 76/min respirations are 18/min, and blood pressure is 130/76 mm Hg. Cardiopulmonary examination shows no abnormalities. There is horizontal nystagmus to the right. Motor strength is 5/5 in all extremities, and sensory examination shows no abnormalities. Finger-to-nose and heel-to-shin testing are normal bilaterally. Weber test shows lateralization to the left ear. The Rinne test is positive bilaterally. Which of the following is the most likely cause of this patient's symptoms?
A. Obstruction of the anterior inferior cerebellar artery
B. Cerebellopontine angle tumor
C. Reduced resorption of endolymph (Correct Answer)
D. Demyelinating plaques
E. Occlusion of the posterior inferior cerebellar artery
Explanation: ***Reduced resorption of endolymph***
- The triad of **intermittent vertigo**, **sensorineural hearing loss** (lateralization to the unaffected ear in Weber and positive Rinne tests), and **tinnitus/aural fullness** is characteristic of **Ménière's disease**.
- This condition is caused by **excessive endolymphatic fluid** pressure due to reduced resorption, leading to distension of the endolymphatic sac.
*Obstruction of the anterior inferior cerebellar artery*
- Leads to a **lateral pontine syndrome** which would present with symptoms like **ipsilateral facial paralysis**, **ataxia**, and **contralateral body deficits**, none of which are described.
- While it can cause hearing loss and vertigo, the **intermittent nature** and specific combination of symptoms point away from an acute stroke.
*Cerebellopontine angle tumor*
- A tumor in this location would typically cause more **slowly progressive** symptoms, including persistent, rather than intermittent, hearing loss, vertigo, and potentially **cranial nerve VII and V deficits**.
- The patient's symptoms are episodic and fluctuating, which is less consistent with a continuously growing mass.
*Demyelinating plaques*
- Demyelinating diseases like **multiple sclerosis** can cause neurological symptoms, including vertigo and hearing deficits, but these are often accompanied by other **widespread neurological signs** like motor weakness, sensory disturbances, or optic neuritis.
- The patient's neurological examination is largely normal aside from the nystagmus and hearing issues, and the symptoms are typically **episodic but without the consistent aural fullness** and hearing loss pattern seen here.
*Occlusion of the posterior inferior cerebellar artery*
- This causes **Wallenberg syndrome** (lateral medullary syndrome), characterized by **ipsilateral ataxia**, **loss of pain/temperature sensation on the ipsilateral face** and **contralateral body**, and dysphagia/hoarseness.
- While vertigo can occur, the specific pattern of hearing loss, tinnitus, and aural fullness is not typical for this condition.
Question 396: A 21-year-old African American woman presents with difficulty breathing, chest pain, and a non-productive cough. She says she took some ibuprofen earlier but it did not improve her pain. Past medical history is significant for sickle cell disease. Medications include hydroxyurea, iron, vitamin B12, and an oral contraceptive pill. She says she received a blood transfusion 6 months ago to reduce her Hgb S below 30%. Her vital signs include: temperature 38.2°C (100.7°F), blood pressure 112/71 mm Hg, pulse 105/min, oxygen saturation 91% on room air. A chest radiograph is performed and is shown in the exhibit. Which of the following is best initial step in the management of this patient's condition?
A. CT angiography
B. Inhaled salbutamol and oral corticosteroid
C. Intra-articular corticosteroid injection with anesthetic
D. ECG
E. Antibiotics and supportive care (Correct Answer)
Explanation: ***Antibiotics and supportive care***
- This patient presents with an acute chest syndrome (ACS) within the context of **sickle cell disease (SCD)**, characterized by new pulmonary infiltrate on chest imaging, coupled with fever, chest pain, tachypnea, and hypoxemia. Broad-spectrum **antibiotics** are crucial due to the high likelihood of bacterial infection (e.g., *S. pneumoniae*, *M. pneumoniae*, *Chlamydia pneumoniae*), possibly complicated by atypical organisms, which can worsen sickling.
- **Supportive care** includes oxygen supplementation for hypoxemia, adequate pain control (often with opioids), and aggressive hydration to prevent further sickling and improve microcirculation. Bronchodilators may be considered if bronchospasm is suspected.
*CT angiography*
- While pulmonary embolism can cause chest pain and dyspnea, **ACS** is a more common and life-threatening complication in sickle cell disease, especially with documented fever and new infiltrates on chest X-ray.
- CT angiography involves radiation exposure and a contrast agent, which could further complicate care in a patient with kidney issues or dehydration, making it less ideal as the **initial** step in a clear case of ACS.
*Inhaled salbutamol and oral corticosteroid*
- This regimen is designed for **asthma exacerbation** or reactive airway disease. While some patients with ACS can have wheezing, the primary pathology is not asthma, and a steroid-only treatment without antibiotics can mask infection and worsen outcomes in ACS.
- **Corticosteroids** should be used cautiously in ACS as they may increase the risk of rebound pain and stroke, and are not a first-line treatment.
*Intra-articular corticosteroid injection with anesthetic*
- This intervention is appropriate for localized **arthritic pain** or inflammation within a joint.
- It is entirely irrelevant to the patient's acute respiratory distress, chest pain, and systemic symptoms, which point to a pulmonary crisis rather than a joint problem.
*ECG*
- An ECG could help rule out acute cardiac events (e.g., myocardial infarction, pericarditis) that may present with chest pain. However, in a young patient with a history of sickle cell disease and clear pulmonary symptoms (hypoxia, infiltrates), **ACS** remains the most probable and critical diagnosis requiring immediate management.
- While an ECG might be performed as part of a comprehensive workup, it is not the **best initial step** and does not directly address the primary problem of ACS.
Question 397: A 63-year-old woman presents to your outpatient clinic complaining of headaches, blurred vision, and fatigue. She has a blood pressure of 171/91 mm Hg and heart rate of 84/min. Physical examination is unremarkable. Her lab results include K+ of 3.1mEq/L and a serum pH of 7.51. Of the following, which is the most likely diagnosis for this patient?
A. Pheochromocytoma
B. Renal artery stenosis
C. Cushing’s syndrome
D. Primary hyperaldosteronism (Conn’s syndrome) (Correct Answer)
E. Addison’s disease
Explanation: ***Primary hyperaldosteronism (Conn’s syndrome)***
- The combination of **hypertension**, **hypokalemia (K+ 3.1 mEq/L)**, and **metabolic alkalosis (pH 7.51)** is highly characteristic of primary hyperaldosteronism.
- Excess aldosterone leads to increased sodium reabsorption and potassium/hydrogen ion excretion, causing these electrolyte imbalances.
*Pheochromocytoma*
- This condition involves episodic **hypertension**, palpitations, sweating, and anxiety due to catecholamine excess.
- While hypertension is present, the absence of paroxysmal symptoms and the specific electrolyte abnormalities (hypokalemia, alkalosis) make it less likely.
*Renal artery stenosis*
- This can cause **secondary hypertension** and occasionally hypokalemia, but it typically presents with **renal bruits**, and the metabolic alkalosis is not a direct or prominent feature.
- The elevated renin-angiotensin-aldosterone axis would lead to secondary hyperaldosteronism, but primary hyperaldosteronism is suggested by the overall clinical picture.
*Cushing’s syndrome*
- Cushing's syndrome is characterized by **central obesity**, striae, moon facies, and **hyperglycemia**, among other symptoms.
- While hypertension and hypokalemia can occur in severe cases, the predominant clinical features are not aligned with this patient's presentation.
*Addison’s disease*
- This condition is characterized by **adrenal insufficiency**, leading to hypoglycemia, **hyponatremia**, **hyperkalemia**, and **hypotension**.
- The patient's hypertension and hypokalemia directly contradict the typical presentation of Addison’s disease.
Question 398: A 26-year-old man presents with a 2-day history of worsening right lower leg pain. He states that he believes his right leg is swollen when compared to his left leg. Past medical history is significant for generalized anxiety disorder, managed effectively with psychotherapy. He smokes a pack of cigarettes daily but denies alcohol and illicit drug use. His father died of a pulmonary embolism at the age of 43. His vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, respiratory rate 14/min. On physical examination, the right lower leg is warmer than the left, and dorsiflexion of the right foot produces pain. Which of the following conditions is most likely responsible for this patient’s presentation?
A. Vitamin K deficiency
B. Hemophilia A
C. von Willebrand disease
D. Factor V Leiden (Correct Answer)
E. Factor XI deficiency
Explanation: ***Factor V Leiden***
- The patient presents with classic symptoms of a **deep vein thrombosis (DVT)** in the right lower leg: pain, swelling, warmth, and pain on dorsiflexion (**Homans' sign**). His history of smoking and a family history of **pulmonary embolism (PE)** in a young father strongly suggest an underlying **thrombophilia**.
- **Factor V Leiden** is the most common inherited thrombophilia, predisposing individuals to venous thromboembolism. The constellation of symptoms and risk factors points directly to this condition.
*Vitamin K deficiency*
- **Vitamin K deficiency** primarily leads to impaired production of clotting factors II, VII, IX, and X, resulting in a **bleeding diathesis**, not thrombotic events.
- Patients would typically present with **bruising, petechiae, gastrointestinal bleeding, or hematuria**, which are not seen here.
*Hemophilia A*
- **Hemophilia A** is an X-linked recessive disorder characterized by a deficiency of **Factor VIII**, leading to severe **bleeding**.
- Symptoms include **spontaneous or prolonged bleeding** into joints (hemarthrosis), muscles, or following trauma, which is the opposite of the patient's presentation.
*von Willebrand disease*
- **Von Willebrand disease (vWD)** is the most common inherited bleeding disorder, caused by a deficiency or defect in **von Willebrand factor**.
- It primarily causes **mucocutaneous bleeding**, such as epistaxis, menorrhagia, and easy bruising, not thrombotic episodes.
*Factor XI deficiency*
- **Factor XI deficiency** is a rare inherited bleeding disorder that typically causes **mild to moderate bleeding**, often associated with trauma or surgery.
- It is not associated with an increased risk of thrombosis and would present with bleeding, not a DVT.
Question 399: A 70-year-old man presents with a complaint of progressive dyspnea on minimal exertion. The patient reports being quite active and able to climb 3 flights of stairs in his building 10 years ago, whereas now he feels extremely winded when climbing a single flight. At first, he attributed this to old age but has more recently begun noticing that he feels similarly short of breath when lying down. He denies any recent fevers, cough, chest pain, nausea, vomiting, or diarrhea. He denies any past medical history except for two hospitalizations over the past 10 years for "the shakes." Family history is negative for any heart conditions. Social history is significant for a 10 pack-year smoking history. He currently drinks "a few" drinks per night. On exam, his vitals are: BP 120/80, HR 85, RR 14, and SpO2 97%. He is a mildly obese man who appears his stated age. Physical exam is significant for a normal heart exam with a few crackles heard at the bases of both lungs. Abdominal exam is significant for an obese abdomen and a liver edge palpated 2-3 cm below the costal margin. He has 2+ edema present in both lower extremities. Lab results reveal a metabolic panel significant for a sodium of 130 mEq/L but otherwise normal. Complete blood count, liver function tests, and coagulation studies are normal as well. An EKG reveals signs of left ventricular enlargement with a first degree AV block. A cardiac catheterization report from 5 years ago reveals a moderately enlarged heart but patent coronary arteries. Which of the following is the most likely cause of this individual's symptoms?
A. Nephrotic syndrome
B. Diastolic heart failure
C. Ischemic cardiomyopathy
D. Toxic cardiomyopathy (Correct Answer)
E. Liver failure
Explanation: ***Toxic cardiomyopathy***
- The patient's history of heavy alcohol consumption ("a few drinks per night") and two past hospitalizations for "**the shakes**" (suggesting **alcohol withdrawal**) are strong indicators of **alcoholic cardiomyopathy**.
- **Alcoholic cardiomyopathy** causes progressive left ventricular enlargement and dysfunction, leading to symptoms like **dyspnea on exertion**, **orthopnea**, **peripheral edema**, and **hepatomegaly**, all of which are present.
*Diastolic heart failure*
- While dyspnea and orthopnea are present, the EKG showing **left ventricular enlargement** and the cardiac catheterization reporting a **moderately enlarged heart** suggest **systolic dysfunction** rather than isolated diastolic dysfunction.
- **Diastolic heart failure** typically presents with preserved ejection fraction and abnormalities in ventricular relaxation or filling, which are not explicitly described or directly implied as the primary issue here.
*Ischemic cardiomyopathy*
- The **cardiac catheterization from 5 years ago** reported **patent coronary arteries**, making **ischemic heart disease** an unlikely primary cause of the current cardiac enlargement and symptoms.
- Although smoking is a risk factor for ischemia, the absence of coronary artery disease on prior catherization and the prominent history of alcohol abuse point elsewhere.
*Nephrotic syndrome*
- Although the patient has **edema** and **hyponatremia**, there is no mention of **significant proteinuria** (a hallmark of nephrotic syndrome) or elevated creatinine, and renal function tests are otherwise normal.
- **Nephrotic syndrome** would not explain the **left ventricular enlargement**, **dyspnea**, or the marked history of alcohol abuse and its cardiotoxic effects.
*Liver failure*
- While the patient has **peripheral edema** and **hepatomegaly**, his **liver function tests are normal**, arguing against significant **cirrhosis or liver failure** as the primary cause of his symptoms.
- The primary symptoms of **dyspnea**, **orthopnea**, and **left ventricular enlargement** point more directly to a cardiac origin rather than liver failure.
Question 400: A 61-year-old man comes to the physician because of a 3-month history of fatigue and progressively worsening shortness of breath that is worse when lying down. Recently, he started using two pillows to avoid waking up short of breath at night. Examination shows a heart murmur. A graph with the results of cardiac catheterization is shown. Given this patient's valvular condition, which of the following murmurs is most likely to be heard on cardiac auscultation?
A. High-frequency, diastolic murmur heard best at the 2nd left intercostal space
B. Harsh, late systolic murmur that radiates to the carotids
C. Blowing, early diastolic murmur heard best at the Erb point
D. High-pitched, holosystolic murmur that radiates to the axilla (Correct Answer)
E. Rumbling, delayed diastolic murmur heard best at the cardiac apex
Explanation: ***High-pitched, holosystolic murmur that radiates to the axilla***
- The patient's symptoms of **fatigue**, **dyspnea on exertion** and **orthopnea**, combined with a heart murmur, are highly suggestive of **heart failure** caused by **mitral regurgitation**.
- A **high-pitched**, **holosystolic murmur** heard best at the **apex** and **radiating to the axilla** is the classic description of mitral regurgitation.
*High-frequency, diastolic murmur heard best at the 2nd left intercostal space*
- This describes the murmur of **pulmonary regurgitation**, which is typically heard best at the **left upper sternal border**.
- The patient's symptoms are more consistent with left-sided heart failure due to a different valvular issue.
*Harsh, late systolic murmur that radiates to the carotids*
- This is the characteristic murmur of **aortic stenosis**, which is heard best at the **right upper sternal border**.
- While aortic stenosis can cause similar symptoms, the description of the murmur and the specific context of heart failure symptoms here point away from it.
*Blowing, early diastolic murmur heard best at the Erb point*
- This describes the **diastolic murmur of aortic regurgitation**, often heard best at the **Erb's point** (3rd intercostal space, left sternal border).
- While aortic regurgitation can cause heart failure, its murmur is diastolic, not holosystolic, and the maximal intensity and radiation differ from the classic mitral regurgitation.
*Rumbling, delayed diastolic murmur heard best at the cardiac apex*
- This is the characteristic murmur of **mitral stenosis**, which is typically preceded by an **opening snap**.
- Mitral stenosis would lead to different hemodynamic changes and often presents with symptoms related to pulmonary congestion, but the murmur timing and quality are distinct from a holosystolic murmur of regurgitation.
