A 70-year-old man with anterior STEMI underwent primary PCI 72 hours ago. He now develops recurrent chest pain and a new holosystolic murmur at the apex radiating to the axilla. Pulmonary artery wedge pressure tracing shows large V waves. What is the most likely mechanism?

• A Ventricular septal rupture
• B Posteromedial papillary muscle rupture ✓
• C Right ventricular dilation
• D Aortic valve stenosis

Explanation

Acute mitral regurgitation from papillary muscle rupture presents with a new holosystolic murmur at the apex and large V waves on wedge pressure tracing. The posteromedial papillary muscle is most commonly affected in inferior or posterior MI because it has single blood supply from the RCA. Anterior MI can also cause it. VSD causes a harsh murmur at the left sternal border, not the apex.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.