At the beginning of this century, debates regarding “what are the main control mechanisms
that ignite the action potential (AP) in heart pacemaker cells” dominated the …

A progressive decline in maximum heart rate (mHR) is a fundamental aspect of aging in
humans and other mammals. This decrease in mHR is independent of gender, fitness, and …

Background: The time variation between consecutive heartbeats is commonly referred to as
heart rate variability (HRV). Loss of complexity in HRV has been documented in several …

Heart rate and heart rate variability (HRV) are mainly determined by the autonomic nervous
system (ANS), which interacts with receptors on the sinoatrial node (SAN; the heart's primary …

Heart rate (HR) and HR variability (HRV), predictors of over-all organism health, are widely
believed to be driven by autonomic input to the sinoatrial node (SAN), with sympathetic input …

Analysis of heart rate variability (HRV) by nonlinear approaches has been gaining interest
due to their ability to extract additional information from heart rate (HR) dynamics that are not …

Backgrounds Panic disorder is a highly prevalent psychiatric disorder that substantially
impairs quality of life and psychosocial function. Panic disorder arises from neurobiological …

The human and dog have sinus arrhythmia; however, the beat-to-beat interval changes
were hypothesized to be different. Geometric analyses (R–R interval tachograms, dynamic …

We aimed to determine how age‐associated changes in mechanisms extrinsic and intrinsic
to pacemaker cells relate to basal beating interval variability (BIV) reduction in vivo. Beating …

The purpose of this study is to characterize and attenuate the influence of mean heart rate
(HR) on nonlinear heart rate variability (HRV) indices (correlation dimension, sample, and …