Background: The presence of patent foramen ovale is associated with an increased risk of paradoxical embolism and stroke. In patients with acute pulmonary embolism the prognosis is worse if patent foramen ovale is present than if it is not.
Case report: A rare case of impending paradoxical embolism in association with pulmonary embolism is reported. The patient presented with recurrent syncope presumably due to embolic transient ischaemic attacks from a large thrombus that was found on echocardiography to be straddling
a patent foramen ovale.
Conclusions: Echocardiography, especially transoesophageal echocardiography should be strongly considered if paradoxical embolism is thought to be complicating acute pulmonary embolism.

Keywords: paradoxical embolism, patent foramen ovale, Pulmonary Embolism