Antiphospholipid Syndrome and Patent Foramen Ovale: A Case Report and Literature Review.

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by arterial, venous, or microvascular thrombosis, pregnancy morbidity, or non-thrombotic manifestations in patients with persistent antiphospholipid antibodies (aPL). Catastrophic APS is a rare and severe form of APS that is defined by the presence of multiple vascular occlusive events. When a patent foramen ovale (PFO) is present, paradoxical embolization can occur, simultaneously leading to arterial and venous thrombosis. We present a complex clinical case of a patient who presented with multiple arterial and venous thrombotic events with positive aPL. The suspicion of catastrophic APS was removed when a PFO was found in a transesophageal echocardiogram, justifying paradoxical embolization. This emphasizes the importance of searching for PFO in patients with APS presenting with simultaneous venous and arterial thrombosis for management and prognosis purposes.