Patent foramen ovale (PFO) is a common congenital cardiac abnormality of the atrial septum which occurs in 25% of the population. It allows communication between the right and left atrium enabling right to left shunting of deoxygenated blood (after birth) which may be linked to strokes or transient ischemic attacks. PFO may also have an association with obstructive sleep apnea (OSA).

OSA is a common medical condition occurring in 9% of adult males and 4% of adult females. It may increase the risk of cardiovascular disease. OSA causes intermittent hypoxia from episodes of apnea and hypopnea during sleep. Consequently, hypoxic pulmonary vasoconstriction ensues which produces an increased right atrial pressure which may generate a right to left shunt during apneic episodes promoting the occurrence of thromboembolic events. The existence of a PFO may be higher in patients with OSA. The presence of a PFO and OSA may increase the risk of stroke. In this review, the association of PFO and OSA is described along with their implications for cardiovascular disease. The relevant literature and treatment options are discussed to elaborate on the significance of the associated pathology.