Patent foramen ovale in patients with haemodynamically significant pulmonary embolism

The prevalence of a patent foramen ovale is about 1 in 4. In cases with venous thromboembolism and raised right heart pressures, a patent foramen ovale may permit paradoxical emboli, which could complicate the course of patients with pulmonary embolism. Echocardiography enables detection of a patent foramen ovale in life. We have studied 85 patients who presented with haemodynamically significant pulmonary embolism as judged by clinical, echocardiographic, or haemodynamic indices and who had an echocardiographic evaluation for patent foramen ovale. 33 patients (39%) had a patent foramen ovale. Clinical symptoms suggestive of paradoxical embolism were more likely in patients with than in those without a patent foramen ovale (39% vs 6%, p = 0.00034), with new neurological deficits occurring in 11 patients (9 vs 2, p = 0.005) and a vascular occlusion in 8 (7 vs 1, p = 0.0096). Arterial oxygen tension was lower in patients with a patent foramen ovale (mean 55 [SD 14] vs 62 [16] mm Hg, p = 0.038). Mortality was not different between the two groups (27% vs 19%). Cardiopulmonary complications in terms of resuscitation, intubation, or the use of catecholamines were more frequently observed in patients with a patent foramen ovale (48% vs 23%, p = 0.028). Patients with a patent foramen ovale and haemodynamically significant pulmonary embolism are more likely to have arterial hypoxaemia and vascular occlusions, possibly due to paradoxical emboli.