A 56-year-old male with syncope presents with hypotension; what is the most likely additional diagnosis based on the clinical picture?

• A. Inferior wall myocardial infarction
• B. Right ventricular infarct
• C. Pulmonary embolism
• D. Aortic dissection

Answer: (B)

When the right ventricle is compromised, it can't fill the left ventricle effectively, so cardiac output plummets and blood pressure falls, which can cause syncope. This preload-dependent situation is classic for a right ventricular infarct, especially when it accompanies an inferior MI from RCA occlusion. Lungs are typically clear because the failure is on the right side and not due to left-sided congestion, and you may see elevated jugular venous pressure. That combination of hypotension with syncope and preserved lung exams points to a right ventricular infarction rather than a primary left-sided issue. Management focuses on supporting preload (often with cautious IV fluids) and avoiding preload-reducing meds like nitrates. The other conditions don’t fit as neatly: an inferior MI without RV involvement would less typically cause this level of hypotension; pulmonary embolism usually presents with dyspnea and hypoxemia; aortic dissection presents with sudden tearing chest pain and often different BP in each arm.