HRV Analysis

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Heart rate variability (HRV) is a noninvasive and practical diagnostic method to measure the of cardiac autonomic function. The vVariability of the heart rate intervals reflects sympathetic and parasympathetic activity which modulates the cardiac functional response to metabolic demands, whereas reduced HRV may be associated with the rate of cardiovascular events and mortality in diabetes. A rRegular exercise training program is a key intervention in the prevention and management of diabetes. The findings of the present review suggest that exercise training may improve HRV in diabetic patients by decreasing the sympathetic activity and increasing the vagal tone. A shift toward greater vagal modulation by exercise training may beneficially affect…show more content…
The principle of HRV measurement is to determine the autonomic balance influences on the sino-atrial node’s intrinsic rhythm. Variation of the beat-to-beat heart rate (HR) intervals reflects the balance between sympathetic and parasympathetic activity which modulates cardiac function. The of beat-to-beat variation in the time of consecutive heartbeats expressed in normal sinus rhythm is recorded on an electrocardiogram (ECG), ranging from a few minutes to 24 hours. The ability of the cardiac autonomics’ responsiveness to dynamically environmental changes results in increased HRV and generally indicates a healthy heart. A reduction in HRV may be indicated an inability in the cardiac autonomic to respond to…show more content…
Although this method is well established, the standardization is not possible throughout the long recording time. Standardization of autonomic function tests such as deep respiration, Valsava manoeuvres and an orthostatic test are based on the time domain assessment. Time domain analysis uses simple mathematics to calculate the amount of variability in normal- to- normal R-R intervals over time which excludes abnormal beats such as premature ventricular contractions and extent noise such as the standard deviation of all R-R intervals (SDNN). The standard deviation of the average of R-R interval over a 5-minute period (SDANN) is another commonly used measure which represents the variation due to circadian rhythms. Although all of these indices cannot be used to identify specific change in sympathetic or parasympathetic activity, theyse are useful clinical implements for detecting abnormal autonomic activity. Other time domain HRV measurement is calculated from successive R-R interval differences such as rMSSD and NN50, where . tThe distribution of successive R-R interval differences is referred to as rMSSD and NN50 refers to number of beat- to- beat changes in excess of 50 ms. These indices reflect parasympathetic activity and are used to detect normal individuals from those with parasympathetic dysfunction. The most commonly used time domain HRV measurements and their definitions
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