Search results
Results from the WOW.Com Content Network
Heart rate variability visualized with R-R interval changes Electrocardiogram (ECG) recording of a canine heart that illustrates beat-to-beat variability in R–R interval (top) and heart rate (bottom). Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the ...
IBI is generally measured in units of milliseconds. In normal heart function, each IBI value varies from beat to beat. This natural variation is known as heart rate variability (HRV). However, certain cardiac conditions may cause the individual IBI values to become nearly constant, resulting in the HRV being nearly zero.
A medical monitoring device displaying a normal human heart rate. Heart rate is the frequency of the heartbeat measured by the number of contractions of the heart per minute (beats per minute, or bpm). The heart rate varies according to the body's physical needs, including the need to absorb oxygen and excrete carbon dioxide.
Regular exercise training is also thought to modify cardiac autonomic control. Individuals who exercise regularly have a 'training bradycardia' (i.e., low resting heart rate) and generally have higher HRV than sedentary individuals. Heart rate variability can be used to assess fatigue and recovery levels, especially for professional athletes.
In most cases, vagal tone is not measured directly. Instead the processes affected by the vagus nerve – specifically heart rate and heart rate variability – are measured and used as a surrogate for vagal tone. Increased vagal tone (and thus vagal action) is generally associated with a lower heart rate and increased heart rate variability.
A number of metrics have been proposed for QTV quantification. The QT variability index (QTVi) has been most frequently reported in the literature: = / / (), where , , , and denote standard deviation and mean of QT interval and heart rate time series, respectively.
Genetic variability, a measure of the tendency of individual genotypes in a population to vary from one another; Heart rate variability, a physiological phenomenon where the time interval between heart beats varies; Human variability, the range of possible values for any measurable characteristic, physical or mental, of human beings
This page was last edited on 21 November 2024, at 18:17 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.