Sleep Apnea and the Risk of Sudden Cardiac Death

It has long been known that obstructive sleep apnea is associated an increased risk in heart conditions. The sleep disorder contributes to high blood pressure, atrial fibrillation and heart attacks. A recent study now indicates that in addition to these problems, obstruction sleep apnea has a significant impact on an individual’s risk for sudden cardiac death. In a study that was published in the Journal of the American College of Cardiology, lead author Apoor Gami, MD, MSc, FACC and cardiologist at Midwest Heart Specialists – Advocate Medical Group in Elmhurst, Illinois writes, “The prevalence of obstructive sleep apnea in Western populations is high and will likely only continue to grow given the obesity epidemic and direct relationship between obesity and sleep apnea.” In this study, 10,701 subjects were followed for over five years. Researchers were looking for a link between sleep apnea and sudden cardiac death. Their inquiry was based upon prior information regarding the propensity of those with sleep apnea of dying more frequently from heart-related causes between 10:00 p.m. and 6:00 a.m., when they are most likely to be asleep. Though these hours are deadly for those with sleep apnea, they are statistically the least likely time for sudden cardiac death to occur in the general population. The nearly 11,000 subjects that were included in the study were monitored for either the need for emergency cardiac resuscitation or for having suffered fatal sudden cardiac death. Over the 5.3 year period, 142 experienced sudden cardiac death. The most common shared symptoms among the group were their age – 60 years old – as well as having a diagnosis of 20 apnea episodes per hour and a recorded lowest oxygen saturation level of below 78%. This saturation level is a result of air not flowing into the lungs, a frequent occurrence in sleep apnea patients as they stop breathing and their blood oxygen levels drop. This particular statistic was shown to increase a patient’s risk of sudden cardiac death by 80%. What the study makes clear is that the risk of sudden cardiac death in those who suffer from sleep apnea, and particularly those who experience an oxygen saturation level below 78%, does not shift from daytime hours to nighttime hours, but instead is simply higher overall. Says Virend K. Somers, MD, PhD, FACC, senior author of the study and a professor of medicine at Mayo Clinic College of Medicine in Rochester, Minnesota, “Treating sleep apnea in one person can improve the quality of life of both bed partners and may have the added benefit of helping to prevent cardiovascular disease. If the spouse sees the bed partner stop breathing repeatedly during sleep, this is an important clue that he or she probably has sleep apnea.”