Unexplained acute coronary occlusion causing anterior myocardial infarction.

We present a diagnostic conundrum with a case of a young woman presenting with an acute myocardial infarction in cardiogenic shock who was found to have an occluded left main stem (LMS). Despite ballooning the LMS, multiple re-occlusions in the same area warranted stent deployment. There was a filling defect in the left aortic sinus which was evaluated further with a CT scan and transoesophageal echocardiogram, confirming a mass consistent with a papillary fibroelastoma. The patient went on to have an left ventricular assist device and died while awaiting a heart transplant, but the mass was never found at surgery.