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?

1. A)Acute decompensated heart failure from inadequate rate control despite digoxin therapy
2. B)Cardiogenic shock from acute mitral regurgitation secondary to papillary muscle infarction
3. C)Digoxin toxicity causing complete heart block and bradycardic shock
4. D)Acute mesenteric ischemia from systemic hypoperfusion and splanchnic vasoconstrictionGABARITO
5. E)Massive pulmonary embolism with acute right ventricular failure