Bonnesen MP, Frodi DM, Haugan KJ, et al. - Continuous monitoring in a high-risk population resulted in detection of correlation between within-individual changes in physical activity and the onset of atrial fibrillation (AF) episodes. For each person, a reduction in daily physical activity by 1-h during the last week was linked with increased odds of AF onset the next day by ≈25%, while the group with the lowest activity overall exhibited the strongest association.

• Continuous monitoring for AF episodes was performed in a total of 1,410 participants from the general population (46.2% women, mean age 74.7 ± 4.1 years) with risk factors but with no prior AF diagnosis during ≈3.5 years. In addition, participants underwent daily accelerometric assessment of physical activity using an implantable loop recorder.

• During the combined duration of monitoring of ≈1.6 million days, 361 participants (25.6%) had occurrences of 10,851 AF episodes lasting ≥ 60 min with a median of 5 episodes (2, 25) each.

• Correlation appeared between reduction in average daily physical activity by 1-h and AF onset the next day.