A patient with inferior wall myocardial infarction is in shock. The reason is: September 2008

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.