Sleep apnea and cardiovascular effects

Obstructive sleep apnea (OSA) is associated with high blood pressure and cardiac arrhythmias. When someone has a sleep apnea event, their heart rate typically slows down. Heart rate then speeds up during the subsequent recovery breaths. It's this repetitive slow-fast cycle during the night that is thought to contribute to arrhythmia. And research has shown that the more oxygen levels decrease during sleep apnea, the greater the risk to the heart and blood vessels. This study was done in a rat model of OSA. The results showed that the low oxygen levels from OSA damaged vital neurons in the rats' brains that regulate blood pressure and heart rate. This could explain why OSA increases risk of high blood pressure and cardiac rhythm problems. More research will be needed to determine if treating OSA can reverse the damage to those neurons.