Heart rate variability (HRV) refers to various methods of assessing the beat-to-beat variation
in the heart over time, in order to draw inference on the outflow of the autonomic nervous …

The sinoatrial node (SAN) is the normal pacemaker of the heart and SAN dysfunction (SND)
is common, but until recently the pathophysiology was incompletely understood. It was …

Endurance athletes exhibit sinus bradycardia, that is a slow resting heart rate, associated
with a higher incidence of sinus node (pacemaker) disease and electronic pacemaker …

Background Heart rate follows a diurnal variation, and slow heart rhythms occur primarily at
night. Objective The lower heart rate during sleep is assumed to be neural in origin, but here …

Exercise has substantial health benefits with pleomorphic vascular, metabolic, psychological
and anti-neoplastic actions resulting in improved quality of life and longevity. Despite these …

Atrial fibrillation (AF) is the most common heart arrhythmia, the risk of which typically
increases with age. This condition is commonly associated with major cardiovascular …

Rationale: Downregulation of the pacemaking ion channel, HCN4 (hyperpolarization-
activated cyclic nucleotide gated channel 4), and the corresponding ionic current, I f …

The positive effects of physical activity are countless, not only on the cardiovascular system
but on health in general. However, some studies suggest a U-shape relationship between …

Objective Leisure-time physical activity (LTPA) has considerable benefits for cardiovascular
health and longevity, while occupational physical activity (OPA) is associated with an …

It is well known that athletes have a low resting heart rate (bradycardia). The bradycardia
can be moderate to severe: reports of heart rates of 40–60 beats min− 1 in athletes are …