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:
“The heart of Paris is like nothing so much as the unending interior of a house. Buildings become furniture, courtyards become carpets and arrases, the streets are like galleries, the boulevards conservatories. It is a house, one or two centuries old, rich, bourgeois, distinguished. The only way of going out, or shutting the door behind you, is to leave the centre.”
—John Berger (b. 1926)
“We honor motherhood with glowing sentimentality, but we don’t rate it high on the scale of creative occupations.”
—Leontine Young (20th century)
“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)