Beta Blockers USMLE Step 1 Practice Question
A 45-year-old man on long-term atenolol for hypertension abruptly discontinues the medication without consulting his physician. Within 48 hours, he presents with BP 210/130 mmHg, HR 118/min, RR 22/min, diaphoresis, palpitations, and substernal chest pain. Troponin is negative. He denies prior angina or coronary disease. Physical examination reveals no peripheral edema or jugular venous distension. Which mechanism best explains this acute hypertensive crisis with tachycardia?
Answer choices
- ABeta-adrenergic receptor upregulation with unopposed catecholamine sensitivityCorrect answer
- BWithdrawal of direct vasodilatory properties inherent to atenolol
- CAcute myocardial infarction from sudden increase in myocardial oxygen demand
- DActivation of the renin-angiotensin-aldosterone system by sympathetic withdrawal
- ERebound hyperthyroidism increasing metabolic rate
- FAcute reduction in nitric oxide bioavailability leading to endothelial dysfunction
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