Paradoxical embolism: a hidden cause of acute lower limb ischaemia in a young adult with diabetes and an atrial septal defect: a case report

Abstract

Paradoxical embolism is a rare but recognised cause of acute systemic arterial occlusion, particularly in the presence of intracardiac defects such as atrial septal defects (ASDs). We report the case of a 36-year-old female with type 2 diabetes (T2DM) who presented with acute right lower limb ischaemia. Initial investigations revealed extensive lower limb arterial occlusions without evidence of underlying atherosclerosis, thrombophilia or arrhythmia. A transoesophageal echo-cardiogram identified a previously undiagnosed secundum ASD with bi-directional shunting. The patient was diagnosed with paradoxical embolism and initially managed with anticoagulation. Despite medical therapy, she developed limb-threatening ischaemia and underwent bilateral iliac embolectomy and a kissing common aorto-iliac revascularisation procedure. Autoamputation of the second right toe eventually occurred. She underwent percutaneous ASD closure using an AmplatzerTM device.
This case highlights the diagnostic challenges of paradoxical embolism in young patients, particularly when confounded by co-morbid conditions such as diabetes. Clinicians should maintain a high index of suspicion for structural cardiac anomalies in patients with acute arterial occlusion and no clear embolic source. Prompt recognition and closure of ASDs can prevent recurrent embolic events and improve outcomes. Transcatheter ASD closure remains a safe and effective treatment strategy in such cases.