Cardio
Pulm
Renal
Neuro
Pharm
100

A 78-year-old man presents with exertional syncope and chest pain. On exam, there is a systolic crescendo–decrescendo murmur best heard at the right upper sternal border. The murmur radiates to the carotids. Diagnosis?

Aortic Stenosis

Clues:

  • Elderly patient
  • Exertional syncope + chest pain
  • Crescendo-decrescendo systolic murmur
  • Right upper sternal border
  • Radiates to carotids

Logic:

Aortic stenosis causes obstruction to LV outflow. During exercise, the heart cannot increase CO enough → syncope. Turbulent flow across narrowed valve gives classic systolic ejection murmur radiating to carotids.

100

A 60-year-old man with a long smoking history presents with fatigue and confusion.

Labs:

Sodium: 118 mEq/L (nl: 135-145)

Serum osmolality: low

Urine osmolality: high

Chest imaging reveals a centrally located lung mass.

Further testing shows ectopic hormone production leading to inappropriate water retention.

Diagnosis?

Small Cell Lung Carcinoma (SIADH)

Clues:

  • Smoker
  • Central lung mass
  • Hyponatremia
  • Low serum osmolarity + high urine osmolarity

Logic:

Small cell carcinoma secretes ectopic ADH → water retention → dilutional hyponatremia

100

A new drug is developed that prevents the demyelinization occurring in the progress of multiple sclerosis. The drug protects the cells responsible for the synthesis and maintenance of myelin in the central nervous system. What are these cells?

Oligodendrocyte

100 — Oligodendrocytes

Clues:

  • CNS myelin
  • Multiple sclerosis

Logic:

Oligodendrocytes make CNS myelin. MS destroys CNS myelin.

Mnemonic:

  • Oligodendrocyte = One cell myelinates many CNS axons
  • Schwann = peripheral nervous system (Schwann sounds more like a proper noun)
100

A 52-year-old man with a history of COPD presents with progressive dyspnea and chronic cough. Pulmonary function tests show decreased FEV₁/FVC ratio with minimal reversibility after bronchodilator administration. He is started on a medication for maintenance therapy.

Several weeks later, he reports dry mouth and mild urinary retention. His symptoms improve significantly, but he is told the medication is particularly effective in his condition due to increased vagal tone–mediated bronchoconstriction.

Which drug was most likely prescribed?

Tiotropium  

M3 receptor → Gq → ↑ IP₃ → ↑ Ca²⁺ → bronchoconstriction

Blocking M3 → bronchodilation 

Clues:

  • COPD
  • Dry mouth + urinary retention
  • Blocks vagal bronchoconstriction

Logic:

M3 antagonists bronchodilate airways. Anticholinergic side effects = dry mouth, urinary retention.

200

A 33 y.o. M presents with mild exertional shortness of breath and a "pounding" heart over the last 5 months. He is uncomfortably aware of his heartbeat while lying on his left side. Vital signs include blood pressure of 150/45 mm Hg and pulse of 73/min. Diagnosis?

Aortic regurgitation

Clues:

  • Wide pulse pressure (150/45)
  • “Pounding” heartbeat
  • Dyspnea
  • Awareness of heartbeat lying left side

Logic:

Blood leaks back into LV during diastole → increased stroke volume + low diastolic pressure → wide pulse pressure. Hyperdynamic circulation causes pounding pulses.

200

A 28-year-old man involved in a motor vehicle collision becomes acutely dyspneic shortly after arrival.

Vitals reveal hypotension and tachycardia.

On exam, there is markedly reduced breath sounds on one side. Shortly after, he develops worsening hypotension.

Cardiac output is decreased due to impaired venous return.

Diagnosis?

Tension pneumothorax

Clues:

  • Trauma
  • Dyspnea
  • Absent breath sounds
  • Hypotension

Logic:

Air trapped in pleural space compresses mediastinum and vena cava → ↓ venous return → obstructive shock.

200

A reaction in the kidney often caused by drugs such as NSAIDs and proton-pump inhibitors leading to eosinophils in the urine without evidence of infection.

Acute interstitial nephritis

Clues:

  • NSAIDs/PPI use
  • Eosinophils in urine

5 P can cause AIN: Penicillins (+ceph), PPI, Pee pills (diuretics), Pain pills (NSAIDS), Pifampin (Rifampin) 

Logic:

Drug hypersensitivity (generally Type IV hypersn) reaction causing interstitial inflammation.

200

A 72-year-old man presents with a resting tremor that improves with movement. Examination reveals bradykinesia, cogwheel rigidity, and decreased facial expression.

Degeneration of neurons in which structure is most likely responsible for this patient’s symptoms?

Substantia nigra pars compacta

Clues: Parkison's

  • Resting tremor
  • Bradykinesia
  • Cogwheel rigidity

Logic:

Parkinson disease d/t degeneration of dopaminergic neurons in substantia nigra pars compacta.

200

A 71-year-old man with type 2 diabetes presents with confusion and diaphoresis. His wife reports that over the past week he has had several episodes of dizziness, especially in the early morning before breakfast. His medications include a recently started oral antihyperglycemic agent.

Past medical history is significant for:

  • Chronic kidney disease (eGFR 28 mL/min/1.73m²)
  • Coronary artery disease
  • Peripheral neuropathy

Labs:

  • Glucose: 42 mg/dL
  • Creatinine: 2.3 mg/dL

He is treated with IV dextrose, but several hours later, he again becomes hypoglycemic.

Which medication is most likely responsible, and why is it contraindicated in this patient?

Glyburide

MOA: 

Close ATP-sensitive K⁺ channels in β-cells → ↑ insulin release (glucose-independent)

Produces active metabolites cleared by the kidneys → accumulation in CKD → prolonged hypoglycemia

Clues:

  • Severe recurrent hypoglycemia
  • CKD patient

Logic:

Sulfonylureas stimulate insulin release regardless of glucose. Glyburide has active metabolites cleared by kidneys → prolonged hypoglycemia in CKD.

300

A patient develops acute crushing chest pain. ECG demonstrates:

  • ST elevations in leads II, III, and aVF
  • Bradycardia

Occlusion of which coronary artery is most likely responsible?

Right Coronary Artery

lues:

  • Inferior STEMI (II, III, aVF)
  • Bradycardia

Logic:

Inferior wall supplied by RCA. RCA also supplies SA/AV nodes (nodal, think right side) → bradycardia common in RCA infarcts.

300

A 46-year-old man is admitted for severe pancreatitis. On hospital day 3, he develops progressive shortness of breath.

Vitals: RR 30/min, SpO₂ 84% on 6 L nasal cannula

ABG: PaO₂- 55 mmHg (nl: 80-100), PaCO₂- 32 mmHg (nl: 35-45)

Chest imaging shows diffuse bilateral opacities. Cardiac catheterization reveals normal left atrial pressure.

Despite increasing inspired oxygen concentration, his arterial oxygenation shows minimal improvement.

Diagnosis?

ARDS (Acute Respiratory Distress Syndrome)

Clues:

  • Severe pancreatitis
  • BL opacities
  • Normal L atrial pressure
  • Refractory hypoxemia

Logic:

ARDS = diffuse alveolar damage causing protein-rich pulmonary edema, not due to heart failure. Oxygen doesn’t correct well because alveoli collapse/fill.

300

A 17 y.o. M presents with intense left flank pain that radiates to the groin. He refers to his symptom as "stone passage," which he has experienced "so many times since childhood." His uncle has the same problem. The urinary cyanide nitroprusside test is positive

Cystinuria 

Clues:

  • Recurrent stones since childhood
  • Family history
  • Positive cyanide-nitroprusside test

Logic:

Defect in COLA amino acid transporter → cystine stones.

Mnemonic: COLA
Cystinuria = defect in

  • Cystine
  • Ornithine
  • Lysine
  • Arginine transport
300

A 45-year-old woman presents with progressive numbness and weakness of the lower extremities. Examination reveals:

  • Bilateral spastic paresis
  • Hyperreflexia
  • Loss of vibration and proprioception below the knees
  • Positive Babinski sign bilaterally

Pain and temperature sensation are preserved.

Degeneration of which spinal cord tracts most likely explains this patient’s findings?

Dorsal columns and lateral corticospinal tracts

Clues:

  • Loss vibration/proprioception
  • Hyperreflexia
  • Babinski

Logic:

Posterior column damage → vibration/proprioception loss.
Corticospinal damage → UMN signs.

Classic for subacute combined degeneration (B12 deficiency).

300

A 66-year-old woman with a history of atrial fibrillation presents with palpitations and shortness of breath for the past several hours. Physical examination reveals an irregularly irregular rhythm. ECG demonstrates atrial fibrillation with a ventricular rate of 148/min. Blood pressure is 122/78 mm Hg.

She is given a medication that slows conduction through the AV node by blocking L-type calcium channels in cardiac nodal tissue.

What drug was most likely administered?

Non-dihydropyridine CCB (Diltiazem/Verapamil)

Clues:

  • AFib with RVR
  • AV node slowing
  • L-type calcium channel blockade

Logic:

AV node depends on calcium conduction. Non-DHP CCBs slow AV nodal conduction.

400

A patient presents with pistol shot-like sounds heard over the femoral artery on auscultation with rapid upstroke and downstroke of carotid and peripheral arteries. There is also rhythmic nodding and bobbing of the head in synchrony with heartbeats. On heart ausculatation, there is a rumbling, low-pitched, middiastolic murmur heard best at the apex. What is the diagnosis?

[Chronic] Aortic Regurgitation

Clues:

  • Pistol-shot femoral sounds 
  • Head bobbing
  • Wide pulse pressure signs
  • Diastolic murmur
  • Austin Flint @ apex: "rumbling, low-pitched, middiastolic murmur"

Logic:

Chronic AR creates hyperdynamic circulation due to blood leaking back into LV. Classic findings:

  • Corrigan pulse
  • Quincke pulse
  • de Musset head bobbing
400

A 54-year-old woman presents with sudden onset dyspnea and pleuritic chest pain 2 days after knee replacement surgery. Physical examination reveals tachycardia and tachypnea. Arterial blood gas demonstrates hypoxemia with respiratory alkalosis. Ventilation to the lungs is preserved, but perfusion to affected regions is decreased.

Which physiologic abnormality best explains this patient’s hypoxemia?

Increased V/Q ratio (dead space ventilation)

Clues:

  • Post-op patient
  • Sudden pleuritic chest pain
  • Hypoxemia
  • Ventilation preserved but perfusion decreased

Logic:

Classic pulmonary embolism. Air reaches alveoli but blood does not → dead space ventilation → high V/Q.


400

A 28-year-old male presents with hemoptysis (coughing up blood) and hematuria. His serum creatinine is 3.2 mg/dL. Immunofluorescence of a renal biopsy reveals smooth, linear deposits of IgG and C3 along the glomerular basement membrane. Identify the disease and its pathophysiology.

Goodpasture Syndrome, autoantibodies to Type IV collagen

Clues:

  • Hemoptysis + hematuria
  • Linear IgG deposition

Logic:

Autoantibodies attack type IV collagen in glomerular + alveolar basement membranes.

Mnemonic for collagen type: SCAB

Type 1 = skeleton

Type 2 = cartilage

Type 3 = arteries

Type 4 = basement membrane

400

A 67-year-old man presents with progressive weakness over the past year. He has difficulty buttoning his shirt and frequently trips while walking. Examination shows diffuse muscle atrophy and fasciculations in both upper extremities. Deep tendon reflexes are brisk in the lower extremities, and plantar reflex testing shows bilateral upgoing toes. Sensory examination is normal.

Which cells are degenerating? And what is the most likely diagnosis?

UMN + LMN; Amyotrophic Lateral Sclerosis

Clues:

  • Fasciculations + atrophy (LMN)
  • Hyperreflexia + Babinski (UMN)
  • Normal sensation

Logic:

ALS affects BOTH upper and lower motor neurons while sparing sensory pathways.

400

A 70-year-old patient with advanced heart failure and sulfa allergy is treated with a loop diuretic. He develops profound hypokalemia, metabolic alkalosis, and sudden hearing loss after dose escalation.

Name the drug.

Ethacrynic acid

Clues:

  • Loop diuretic
  • Sulfa allergy
  • Ototoxicity

Logic:

Ethacrynic acid is the only loop diuretic WITHOUT sulfa group. Loop diuretics can cause:

  • Ototoxicity
  • Hypokalemia
  • Metabolic alkalosis
500

A 4-year-old boy is brought to the physician for fatigue and poor exercise tolerance. Physical examination reveals a fixed split S2 and a systolic ejection murmur heard best at the left upper sternal border. Echocardiography demonstrates right atrial and right ventricular enlargement.

What is the most likely diagnosis?

Atrial Septal Defect

Clues:

  • Fixed split S2
  • Systolic ejection murmur
  • RA/RV enlargement

Logic:

Left-to-right shunt increases flow through pulmonic valve → flow murmur. Fixed split S2 occurs because RV overload delays pulmonic valve closure regardless of respiration.

500

A 63-year-old man presents with progressive dyspnea. He has smoked 2 packs of cigarettes daily for 40 years. Pulmonary function testing demonstrates:

  • Markedly decreased FEV1/FVC ratio
  • Increased total lung capacity
  • Increased residual volume
  • Decreased DLCO

Arterial blood gas analysis shows mild hypoxemia. Physical examination demonstrates hyperresonance to percussion and decreased breath sounds bilaterally.

Which structural change most likely accounts for this patient’s decreased DLCO?

Destruction of alveolar septa/capillary beds

Clues:

  • Smoker
  • Obstructive pattern
  • Increased TLC/RV
  • Decreased DLCO

Logic:

Emphysema destroys alveolar walls and pulmonary capillaries → reduced surface area for gas diffusion → ↓ DLCO.


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500

A 19-year-old man presents with edema and dark urine. He has a history of intravenous drug use. Labs show mild proteinuria and hematuria, low C3 with normal C4, and elevated creatinine.

Renal biopsy:

  • Mesangial and endocapillary proliferation
  • Capillary wall remodeling with duplication of the basement membrane
  • Immunofluorescence shows granular deposition along the capillary walls and mesangium

Diagnosis?

Membranoproliferative glomerulonephritis (MPGN)

Clues:

  • Low C3 normal C4
  • Tram-track GBM duplication
  • Granular IF pattern

Logic:

Immune complex deposition activates complement → mesangial proliferation + GBM remodeling.

500

A 64-year-old man presents with progressive difficulty climbing stairs and rising from a chair over the past several months. He also reports dry mouth and erectile dysfunction. He has a 40-pack-year smoking history. Physical examination demonstrates proximal muscle weakness in the lower extremities. Deep tendon reflexes are decreased but improve after repeated muscle contraction. Extraocular movements are intact.

What is the most likely underlying mechanism of the condition + diagnosis?

Autoantibodies against presynaptic voltage-gated calcium channels; Lambert Eaton

Clues:

  • Proximal weakness
  • Improves with repeated use
  • Autonomic symptoms
  • Smoker

Logic:

Paraneoplastic syndrome from small cell lung cancer.
Antibodies attack presynaptic voltage-gated calcium channels → ↓ ACh release.

Improves with repeated stimulation because calcium accumulates presynaptically.

500

A 72-year-old man with Parkinson disease is brought by his wife because of worsening hallucinations and compulsive gambling behavior over the past several months. His tremor and bradykinesia had initially improved after initiation of a new medication. Physical examination demonstrates resting tremor, masked facies, and cogwheel rigidity.

The medication most likely responsible for this patient’s new symptoms acts primarily through which of the following mechanisms?

Direct stimulation of dopamine receptors (Pramipexole or ropinirole)

Clues:

  • Parkinson treatment
  • Hallucinations
  • Compulsive gambling

Logic:

Dopamine agonists overstimulate mesolimbic dopamine pathways → impulse-control disorders and psychosis.

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