Study shows that a heart defect may make sleep apnea worse through contributing to oxygen deprivation.
People with sleep apnea stop breathing temporarily many times during the night, because of an obstruction of the upper airways. This breathing cessation often leads to a fall in the oxygen concentration of the blood, known clinically as oxygen desaturation. In contrast, a healthy person can hold their breath and not suffer oxygen desaturation. Researchers in Gothenburg, Sweden, now report on a new study that sheds light on this puzzle.
They looked at the presence of a heart defect called Patent Foramen Ovale (PFO) among 30 patients with sleep apnea. PFO is an opening between the right and left atria – the upper chambers of the heart. It is a remnant of the fetal circulation which is still present in one in four adults.
In the current study, PFO was more common among patients with sleep apnea who had oxygen desaturation than among those who had sleep apnea but were not as much troubled with oxygen desaturation. The researchers believe that shunting of deoxygenated blood through the PFO contributes to oxygen desaturation in sleep apnea.
The finding is significant, because PFO can be closed using a catheter technique and this could be a treatment option for those sleep apnea patients with severe oxygen desaturation.
Source: European Respiratory Journal, January 2007