Patent foramen ovale as a cause of platypnea orthodeoxia syndrome presenting in pregnancy: A case report and review of the literature

Abstract

Background At 8 weeks into her third IVF pregnancy, a 40-yearold doctor presented to the Royal Derby Hospital with dyspnoea. Her breathing had worsened since the drainage of 5 litres of ascites from ovarian hyperstimulation syndrome 3 weeks prior. Her symptoms deteriorated and she was intermittently hospitalised from 28 weeks, as she was unable to sit upright without desaturating to 75% in air. This presentation was consistent with Platypnea-Orthodeoxia Syndrome (shortness of breath and arterial desaturation when upright which improves when supine). Investigations including chest X-ray, VQ scan, CTPA, Spirometry, Echo and ECG were normal. Bubble echo was initially normal, but when repeated 2 weeks later it demonstrated a right to left shunt consistent with a patent foramen ovale (PFO). She underwent a caesarean section at 35 weeks following which her symptoms resolved entirely. Objectives To establish the incidence of PFO in women of reproductive age, presenting symptoms, diagnostic tests and options for management. Methods Review of recent literature via a web based search. Results Patent Foramen Ovale is known to affect up to 1 in 3 adults based on autopsy findings from around 1000 'normal' hearts. The incidence in those aged under 30 years is 34.3%, falling to 25.4% in the over 40s. Size is known to increase with age. PFO affects men and women equally, with no difference in size between genders. It has long been recognised as a cause of unexplained stroke, particularly in those under 55, where the incidence is thought to rise to 56%. The vast majority of adults are asymptomatic, although it is occasionally associated with clinical syndromes including decompression syndrome in scuba divers, migraine (particularly with aura) and rarely with Platypnea-orthodeoxia syndrome. The diagnosis is made via Echocardiography, with trans-oesophageal echo considered the gold standard. In the UK use of 'bubble echo' has improved detection, as saline contrast is injected into a peripheral vein during the valsalva manoeuvre, following which bubbles can be seen crossing the septum. Management options include secondary prevention of paradoxical embolic stroke with anticoagulation, and percutaneous transcatheter closure. This method has now been developed for use in the second trimester to allow closure with minimal fetal radiation exposure. Conclusion Patent foramen ovale is a relatively common phenomenon in women of childbearing age and should therefore feature in the differential diagnosis of worsening shortness of breath in pregnancy, especially if positional