Adrenal Disorders USMLE Step 1 Practice Question
A 55-year-old man with a 10-year history of hypertension treated with lisinopril presents to the emergency department with acute onset palpitations, tremor, and profuse diaphoresis. He reports the symptoms began suddenly 2 hours ago without clear precipitant. Vital signs: BP 215/128 mmHg, HR 122/min, RR 22/min, temperature 37.1°C. Physical examination reveals an anxious, diaphoretic patient with mild tremor. Laboratory studies show plasma free metanephrines elevated at 5-fold the upper limit of normal. Abdominal CT imaging reveals a 2.4-cm left adrenal mass with homogeneous appearance and no fat plane invasion. The patient denies orthostatic dizziness or syncope. Which of the following best explains the acute cardiovascular findings in this patient?
Answer choices
- ADirect suppression of cardiac parasympathetic tone leading to increased atrioventricular nodal conduction
- BAlpha-2 adrenergic receptor activation causing decreased peripheral vascular resistance and reflex tachycardia
- CAlpha-1 and beta-1 adrenergic receptor stimulation causing vasoconstriction, increased contractility, and tachycardiaCorrect answer
- DExcessive catecholamine-induced inhibition of renin release resulting in sodium wasting and prerenal azotemia
- ECatecholamine-mediated insulin suppression causing hyperglycemia and osmotic diuresis
- FChronic activation of the renin-angiotensin-aldosterone system leading to hypokalemic metabolic alkalosis
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