Changes in heart rhythm power spectrum during human aging

Age-Related Changes in Cardiac Autonomic Modulation and Heart Rate Variability in Mice

“…It must be acknowledged, however, that the intrinsic HR in the young group was similar to the average resting HR, confirming that, contrary to young adult humans ( Tan et al, 2009 ), resting HR in young adult mice is not predominantly modulated by vagal influences. Most importantly, our data indicate that mice exhibit age-related changes in cardiac ANS regulation (i.e., decline in vagal functioning) and automaticity of cardiac pacemaker cells (i.e., reduced intrinsic HR) that closely recapitulate those observed in human populations ( Jose and Collison, 1970 ; Korkushko et al, 1991 ; Poller et al, 1997 ; Umetani et al, 1998 ; Antelmi et al, 2004 ; De Meersman and Stein, 2007 ). Moreover, we also found that, similar to humans ( White et al, 1994 ), maximal β-adrenergic receptor stimulation with isoprenaline provoked a smaller HR response in the older group.…”

“…For example, basal plasma norepinephrine levels increase with age ( Pfeifer et al, 1983 ), suggesting that sympathetic nervous activity may be elevated in elderly people and affect the electrical stability of both atria and ventricles ( Shen and Zipes, 2014 ; Kalla et al, 2016 ; Curtis et al, 2018 ). Moreover, an age-related impairment in cardiac vagal modulation has been documented in studies reporting (i) a decline in the vagal component of heart rate variability (HRV) – a surrogate measure of ANS function – and (ii) diminished heart rate (HR) responses to blockade of muscarinic acetylcholine receptors with advancing age ( Korkushko et al, 1991 ; Poller et al, 1997 ; Umetani et al, 1998 ; Antelmi et al, 2004 ; De Meersman and Stein, 2007 ). Therefore, the aim of this study is to assess whether the aging process in mice is characterized by similar changes in cardiac autonomic modulation and HRV, and whether these changes lead to increased vulnerability to cardiac arrhythmias.…”