Atrial fibrillation is a heart rhythm disorder marked by irregular, often rapid contractions of the heart’s atria.
More than 40 million people worldwide suffer from this condition, which increases the risk of stroke by five times.
The afternoon siesta has long been seen as a quick way to recharge and lift your mood. But recent studies suggest that how long you nap matters for your health.
Research from the University Hospital of Juan Ramón Jiménez in Spain found that naps of 15 to 30 minutes are beneficial, while longer naps may be linked to irregular heartbeats.
What Researchers Discovered
To see whether daytime napping could cause atrial fibrillation, researchers analyzed data from a University of Navarra study. The study included more than 20,000 people who reported no heart problems at the start.
Participants were divided into three groups based on their average duration of daytime sleep. The first group consisted of people who did not have a habit of napping during the day. The second group included those who napped for less than 30 minutes. The third group comprised individuals who napped for 30 minutes or longer.
Every two years, volunteers filled out a detailed questionnaire about their health, lifestyle, working hours, and more.
At the end of the project, researchers found that those who napped for 30 minutes or more had a nearly doubled risk—56% higher—of developing atrial fibrillation. Meanwhile, those who took short naps (less than 30 minutes) faced no such risk.
Dr. Díaz-Gutiérrez, the study’s lead author, says the optimal daytime nap is 15 to 30 minutes. He offers several possible explanations for the link between daytime sleep and heart health.
For instance, longer daytime naps may disrupt circadian rhythms, leading to shorter nighttime sleep, more nighttime awakenings, and less physical activity.
In contrast, a short nap of 15 to 30 minutes can help stabilize the internal clock, lower blood pressure, and reduce stress.
Dr. Díaz-Gutiérrez says people with nighttime sleep problems should not rely on daytime naps, because naps don’t make up for lost nighttime sleep.
The team presented their findings at the Congress of the European Society of Cardiology.
Atrial fibrillation can cause rapid heartbeat, shortness of breath, and dizziness, and is especially common in older adults. Other key risk factors include poor diet that raises cholesterol, unhealthy habits, obesity, high blood pressure, and genetic predisposition.
