Multiday Heart Rate Rhythms Common in Young Adults

In a US retrospective observational cohort study of 623 young adults, significant infradian (multiday) heart rate rhythms were detected in 70% of participants, with 36% showing two or more distinct rhythms. Using up to four years of wearable and questionnaire data from the University of Notre Dame’s NetHealth project, researchers identified annual, biannual, and approximately 10-week rhythms as the most common patterns. Within the 4–45-day range, participants clustered into three multiday chronotypes based on dominant periodicities: weekly (~7 days), monthly (~25–35 days), and multi-month (>35 days). Heart rate rhythms were influenced by environmental cycles, particularly day-of-week and seasonal patterns, and were synchronized with the menstrual cycle in most menstruating women; however, monthly rhythms were also observed in men and menopausal women. These findings indicate that infradian heart rate rhythms are common even among healthy young people and highlight the need for further research into their underlying mechanisms and potential relationships with autonomic function, disease risk, and disease-specific symptoms. Source: https://www.thelancet.com/