Unusual Case of Acute Coronary Syndrome Due to Compression of the Left Main Coronary Artery From a Contained Aortic Root Perforation

We present an intriguing and rare case of a 71-year-old male who presented with a non-ST elevation myocardial infarction (NSTEMI). Initial coronary angiography revealed severe and unusual systolic extrinsic compression of the left main coronary artery (LM), warranting further advanced imaging investigations. Computed tomography angiography (CTA) and transesophageal echocardiography (TEE) were employed to determine the underlying cause, which was identified as a contained aortic rupture leading to the formation of a pseudoaneurysm in the left coronary sinus of Valsalva and aortic root. This condition was found to be a sequela of previously undiagnosed endocarditis, likely secondary to lower extremity osteomyelitis and bacteremia, for which the patient received prolonged intravenous (IV) antibiotic therapy. This case highlights the critical role advanced imaging techniques play in accurately diagnosing and characterizing complex cardiovascular abnormalities, enabling early intervention and optimizing patient outcomes. Healthcare providers should remain vigilant for such atypical presentations to ensure timely and appropriate management.