A 72-year-old man is found collapsed 5 days after an anterior STEMI. He is pulseless but the monitor shows organized narrow complexes. Emergency echocardiography shows a large pericardial effusion. What is the most likely diagnosis?

• A Ventricular septal rupture
• B Acute mitral regurgitation from papillary muscle rupture
• C Ventricular tachycardia with loss of output
• D Rupture of the left ventricular free wall ✓

Explanation

Free wall rupture typically occurs 3 to 7 days after a transmural infarction, most often in hypertensive elderly women with a first infarction. Blood escapes into the pericardium causing tamponade, and the classic rhythm is electromechanical dissociation: organized electrical activity without a palpable pulse. Septal rupture produces a murmur and biventricular failure, papillary rupture causes severe mitral regurgitation with pulmonary edema, and pulseless ventricular tachycardia shows wide disorganized complexes.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.