This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'A patient with inferior wall myocardial infarction is in shock. The reason is: September 2008 \nSelect and explain. \nA. Right ventricular infarction, B. Mitral regurgitation, C. Infarction causing septal defect, D. Decreased ejection fraction from left ventricle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: Right ventricular infarction Acute myocardial infarction (MI) involving only the right ventricle is a rare event. Much more commonly, right ventricular infarction is associated with infarction of the inferior wall of the left ventricle, occurring in more than one-third of such cases. In such patients, the infarction typically involves the left ventricular inferior-posterior wall, septum, and posterior right ventricular free wall. A right ventricular infarct should be considered in all patients who present with an acute inferior wall myocardial infarction, especially in the setting of a low cardiac output. Patients may describe symptoms consistent with hypotension. Other presentations include high-grade atrioventricular block, tricuspid regurgitation, cardiogenic shock, right ventricular free wall rupture, and cardiac tamponade.', 'role': 'assistant'}]