Valvular Heart Disease USMLE Step 1 Practice Question
A 58-year-old man with a history of rheumatic mitral stenosis presents to the emergency department with palpitations, dyspnea, and chest discomfort. On examination, he is tachycardic with an irregular rhythm. An electrocardiogram shows atrial fibrillation with a ventricular rate of 140 bpm. Chest X-ray reveals pulmonary edema. He is treated with intravenous furosemide and digoxin. Six hours after admission, despite appropriate diuretic therapy and rate control (heart rate now 95 bpm), the patient develops severe hypotension (BP 78/50 mmHg), worsening dyspnea, cool extremities, and altered mental status. Arterial blood gas shows pH 7.28, lactate 5.2 mmol/L (normal <2), and mixed metabolic and respiratory acidosis. Which of the following complications most likely explains this acute clinical deterioration?
Answer choices
- AAcute decompensated heart failure from inadequate rate control despite digoxin therapy
- BCardiogenic shock from acute mitral regurgitation secondary to papillary muscle infarction
- CDigoxin toxicity causing complete heart block and bradycardic shock
- DAcute mesenteric ischemia from systemic hypoperfusion and splanchnic vasoconstrictionCorrect answer
- EMassive pulmonary embolism with acute right ventricular failure
- FAcute ischemic stroke from cardioembolism with secondary cerebral edema
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.