A patient with acute STEMI develops a new pansystolic murmur loudest at the left sternal border 5 days post-infarction. Echocardiography reveals a left-to-right shunt. Which intervention is most appropriate?

• A IV nitroprusside infusion alone and reassessment at 2 weeks
• B Primary percutaneous coronary intervention to the infarct artery
• C High-dose diuresis and bed rest with delayed elective repair
• D Urgent surgical or percutaneous repair after haemodynamic stabilisation with IABP ✓

Explanation

A new pansystolic murmur at the left sternal border with a left-to-right shunt on echocardiogram after STEMI is diagnostic of post-infarction ventricular septal defect (VSD), a mechanical complication. This carries extremely high mortality (30-day mortality > 90% without intervention). Management requires haemodynamic stabilisation — ideally intra-aortic balloon pump (IABP) or mechanical circulatory support — followed by urgent surgical repair or transcatheter VSD closure. Medical management alone or delayed repair confers unacceptable mortality. PCI to the infarct artery does not close the defect.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.