Knowra Heart rate variability Heart rate variability Heart rate variability (HRV) is the variation in time intervals between successive heartbeats. It reflects changing influences on the heart’s pacing, especially those of the autonomic nervous system.
Autonomic nervous system : The nervous system division that regulates involuntary functions, including heart rate, through sympathetic and parasympathetic pathways. Its opposing pathways continually adjust the heart’s pacing and create much of short-term HRV.
R–R interval : The time between successive R waves in an electrocardiogram, corresponding approximately to the interval between heartbeats. HRV is calculated from the changing lengths of these intervals.
Wearable technology : Electronic devices worn on the body that collect data or provide digital functions. Wrist devices estimate HRV from pulse signals, often during sleep or rest.
Low heart rate variability : A comparatively small variation in heartbeat intervals under defined measurement conditions. Low readings can accompany several states, but do not by themselves diagnose disease or poor health.
Heart rate variability biofeedback : A practice that uses real-time feedback on heart rhythm or breathing to train paced respiration and related patterns. Studies examine whether training can improve self-regulation and support specific clinical outcomes.
Vagus nerve : The cranial nerve that carries major parasympathetic signals between the brain and organs, including the heart. Vagal signals can rapidly slow the heart, producing beat-to-beat variation.
Normal-to-normal interval : The interval between successive normal heartbeats, excluding intervals associated with ectopic beats or artifacts. Standard HRV analysis uses these cleaned intervals rather than every detected beat.
Photoplethysmography : An optical method that detects changes in blood volume in tissue using light. Many consumer wearables infer pulse-interval variability from photoplethysmography rather than ECG.
High heart rate variability : A comparatively large variation in heartbeat intervals under defined measurement conditions. Higher readings are not universally better; age, rhythm, measurement, and context affect interpretation.
Resonance frequency breathing : Slow paced breathing near an individual’s cardiovascular resonance frequency, often around six breaths per minute. It can amplify respiratory-linked HRV, raising questions about what training-related changes signify.
Show all 28