Acute coronary syndrome due to papillary fibroelastoma detected by intravascular ultrasound imaging: a case report.

Background: Papillary fibroelastomas (PFEs) are rare benign cardiac tumours that most commonly affect the left-sided heart valves, especially the aortic valve. Although frequently asymptomatic, PFEs can cause embolic events, arrhythmias, or coronary artery occlusion. Case summary: A 57-year-old woman with no significant medical history presented with acute chest pain and was urgently transferred to our hospital. Electrocardiography on admission showed ST-segment elevation in aVR with diffuse ST-segment depression, consistent with acute coronary syndrome (ACS). While in the emergency department, she developed a refractory ventricular fibrillation storm requiring cardiopulmonary resuscitation, intravenous amiodarone, and repeated defibrillation. Sinus rhythm was not restored, so veno-arterial extracorporeal membrane oxygenation (VA-ECMO) was initiated in the catheterization laboratory, followed by immediate coronary angiography (CAG). CAG revealed an intracoronary mass in the left main trunk (LMT). Intravascular ultrasound (IVUS) identified a heterogeneous, mulberry-like mass occluding the LMT and protruding into the aorta. Given suspicion of a soft tissue tumour near the coronary artery origin, surgical resection was performed. Histopathology confirmed the diagnosis of PFE. Discussion: This case highlights the crucial role of IVUS in diagnosing rare causes of ACS, such as PFE-related coronary occlusion. IVUS can differentiate tumour from thrombus, enabling timely surgical intervention and improving clinical outcomes.