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
Famous quotes containing the words heart, rate and/or variability:
“I like people and I like them to like me, but I wear my heart where God put it—on the inside.”
—F. Scott Fitzgerald (1896–1940)
““Terence, this is stupid stuff:
You eat your victuals fast enough;
There can’t be much amiss, ‘tis clear,
To see the rate you drink your beer.”
—A.E. (Alfred Edward)
“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 (1819–1891)