The study was to determine whether poor sleep itself is a risk factor for AF. Poor sleep quality appears to be an important risk factor for atrial fibrillation, report scientists in the first study of its kind to demonstrate a relationship between poor sleep quality independent of sleep apnea and a higher risk of atrial fibrillation (AF). The study was published in HeartRhythm.

AF is an irregular, rapid heart rate that may cause symptoms such as heart palpitations, fatigue, and shortness of breath. It can substantially reduce the quality of life and is associated with heightened risks of stroke, dementia, heart attack, kidney disease, and death. Obstructive sleep apnea has been established as a risk factor for AF, but the mechanism is unclear.

While episodes of abnormally slow or shallow breathing (hypopnea) and apnea may cause cardiopulmonary stress, induce inflammation, and contribute to cardiovascular disease, obstructive sleep apnea also results in poor sleep. Aspects of poor sleep such as altered sleep duration, efficiency, and architecture have been linked to other cardiovascular diseases.

Sleep Apnea Vs. Atrial Fibrillation

While a relationship between sleep apnea and AF has previously been demonstrated, the effect of sleep itself on AF risk has remained unknown. Strategies to enhance sleep quality are different from those that focus on relieving airway obstruction, so it is important to understand the relationship between sleep itself and AF.

Investigators drew on four different studies to determine whether poor sleep itself is a risk factor for AF. First, they used the global, Internet-based Health eHeart Study and determined that individuals with more frequent nighttime awakenings while trying to sleep more often carried a diagnosis of AF. Within a subset of these individuals who had undergone formal sleep studies, they found that less REM sleep in particular predicted future AF.

These results provide more evidence that sleep quality is important to cardiovascular health and specifically to AF. Investigators determined that there was no evidence that sleep duration per se was a risk factor for AF. Instead, they consistently found sleep disruption to be an important risk factor. While the underlying mechanisms are still unknown, these findings may motivate novel ways to think about, and hence future research into, factors that influence AF risk.

This is the first study to demonstrate a relationship between worse sleep quality independent of sleep apnea and a higher risk of AF. These data provide compelling evidence that sleep quality itself, even independent of sleep apnea, is an important determinant of AF risk.

Treatments

While there are several available treatments for AF, prevention of the disease would be ideal. The good news is that sleep quality can be modifiable and is something that at least to some degree is under the control of the individual. 

Disruption Of Sleep

Sleep disruption consistently predicted AF before and after adjustment for OSA and other potential confounders across several different populations. Sleep quality itself may be important in the pathogenesis of AF, potentially representing a novel target for prevention.