Reversed shunting in CREST syndrome.

The patent foramen ovale (PFO) is one of the most common congenital defects and may as well stand for "potential for opening" in addition to patent foramen ovale. Although patients are usually asymptomatic because the defect is flap-like and does not permit significant left-to-right shunting, the pathological conditions that result in cardiac rotation or higher than normal right atrial pressures can reverse the normal left atrial to right atrial pressure gradient and cause a right-to-left shunt through a PFO. Pulmonary complications of systemic sclerosis (SSc) are common, and are the leading cause of SSc-related death. The most common pulmonary manifestations of SSc are pulmonary hypertension (PAH), interstitial lung disease, and any combination thereof. Compared with the idiopathic form of PAH (IPAH), patients with SSc-associated PAH have a threefold increased risk of death and may receive a diagnosis late in the course of disease because of insidious onset and the high prevalence of cardiac, musculoskeletal, and pulmonary parenchymal comorbidities. © 2015 Wiley Periodicals, Inc. J Clin Ultrasound 44:390-391, 2016.