Associations of Accelerometer-Derived Moderate-to-Vigorous Physical Activity and Atrioventricular Block in a Healthy Elderly Population.

Background: There is limited information on protective factors related to atrioventricular (AV) block.

Objective: This study examines the association between accelerometer-derived moderate-to-vigorous physical activity (MVPA) and AV block in healthy elderly individuals.

Methods: A total of 23,590 UK Biobank participants ≥60 years involved in a wrist-worn accelerometer study with no history of hypertension, diabetes mellitus, dyslipidemia, and coronary heart disease were analyzed. The associations of MVPA with primary (second- or third-degree AV block) and secondary outcome (third-degree AV block, pacemaker implantation) were evaluated by Cox regression analysis. The associations of MVPA with electrocardiogram parameters were evaluated by linear regression analysis.

Results: The mean age was 63.8 ± 2.8 years, and 57.4% were women. During the median follow-up period of 6.1 years, 115 primary outcome events occurred. As compared with quintile 1 (<89 min/week), those in quintile 4 (280-449 min/week) had a 63% lower incidence of primary outcome (HR: 0.37, 95% CI: 0.19 to 0.73, P=0.004); however, the result was attenuated in quintile 5. This pattern was consistently observed in the relationship between MVPA and third-degree AV block (quintile 4 vs quintile 1: HR: 0.29, 95% CI: 0.11 to 0.74, P=0.010) and pacemaker implantation. MVPA per 150 min/week increase was independently negatively associated with normalized PQ interval (msec) (β: ‒2.13, 95% CI: ‒3.03 to ‒1.24, P<0.001).

Conclusions: In the healthy elderly population, MVPA was associated with a lower risk of second- or third-degree AV block, which correlates with the reduction of normalized PQ interval. However, excessive MVPA attenuated the results.