Upper threshold of accelerometer-derived moderate-to-vigorous physical activity for beneficial impact on arrhythmia in healthy population

Abstract Background Upper threshold of accelerometer-derived moderate-to-vigorous physical activity (MVPA) for beneficial impact on arrhythmia in healthy population is unknown. Methods We analyzed 66,845 UK Biobank participants involved in a wrist-worn accelerometer study with no history of hypertension, diabetes mellitus, dyslipidemia, coronary heart disease, and heart failure. The relationships between MVPA min/week (as a continuous variable) and arrhythmias (atrial fibrillation, sick sinus syndrome, second- or third-degree atrioventricular block, and ventricular tachycardia) were assessed using restricted cubic splines with multivariable adjustments. The number of knots was determined using the Akaike information criterion, and the reference value for the spline curves was set at 0 min/week. Results Of 66,845 participants, mean age was 61.0 ± 7.9 years, and 60.4% were women. During the median follow-up period of 6.1 (interquartile range: 5.6–6.6) years, 1403 atrial fibrillation, 63 sick sinus syndrome, 167 second- or third-degree atrioventricular block, and 66 ventricular tachycardia occurred. In spline curve analysis, the risks of atrial fibrillation, sick sinus syndrome and atrioventricular block decreased with increasing MVPA up to the World Health Organization (WHO) extended recommendation (≥300 min/week), but increased, forming a J-shape relationship. Excessive MVPA attenuated the beneficial effects on atrial fibrillation, sick sinus syndrome, and second- or third-degree atrioventricular block with threshold of 900 min/week, 510 min/week, and 435 min/week, respectively. There was no upper threshold for ventricular tachycardia incidence, as it was not associated with MVPA. Conclusions In a healthy middle age population, MVPA was associated with a lower risk of atrial fibrillation, sick sinus syndrome, and second- or third-degree atrioventricular block. However, excessive MVPA attenuated the results. Accelerometers or wearable devices could be an option to ensure only a modest amount of MVPA and avoid excessive MVPA.