Heart Rate Variability
Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the variation in the beat-to-beat interval.
Other terms used include: "cycle length variability", "RR variability" (where R is a point corresponding to the peak of the QRS complex of the ECG wave; and RR is the interval between successive Rs), and "heart period variability".
See also Heart rate turbulence, Sinus rhythm.
Methods used to detect beats include: ECG, blood pressure, and the pulse wave signal derived from a photoplethysmograph (PPG). ECG is considered superior because it provides a clear waveform, which makes it easier to exclude heartbeats not originating in the sinoatrial node. The term "NN" is used in place of RR to emphasize the fact that the processed beats are "normal" beats.
Read more about Heart Rate Variability: Clinical Significance, Mental and Social Aspects, Variation, Heart Rate Variability Phenomena, HRV Artifact, HRV Analysis, Duration and Circumstances of ECG Recording, Changes of HRV Related To Specific Pathologies, Modifications of HRV By Specific Interventions, Normal Values of Standard Measures of HRV
Other articles related to "heart, heart rate variability":
... times a week was associated with a 50% reduction in the risk of heart attack or stroke ... does not imply causation.) There is some research suggesting that greater resting heart rate variability is associated with orgasms through penile-vaginal intercourse without additional simultaneous ... As a differential hypothesis, resting heart rate variability measures were unrelated to orgasmic frequency from non-coital sexual activities ...
Famous quotes containing the words variability, heart and/or rate:
“The grand points in human nature are the same to-day they were a thousand years ago. The only variability in them is in expression, not in feature.”
—Herman Melville (18191891)
“And finally I twist my heart round again, so that the bad is on the outside and the good is on the inside, and keep on trying to find a way of becoming what I would so like to be, and could be, if ... there werent any other people living in the world.”
—Anne Frank (19291945)
“This is the essential distinctioneven oppositionbetween the painting and the film: the painting is composed subjectively, the film objectively. However highly we rate the function of the scenario writerin actual practice it is rated very lowwe must recognize that the film is not transposed directly and freely from the mind by means of a docile medium like paint, but must be cut piece-meal out of the lumbering material of the actual visible world.”
—Sir Herbert Read (18931968)