The Prognostic Importance of Heart Rate Variability
614 Words3 Pages
1.1. Heart rate variability:
Heart rate variability (HRV) reflects the variations in the intervals between heart beats (R waves) over time. The time between two consecutive R waves is termed the R-R interval; it is measured in milliseconds, and is controlled by the autonomic nervous system 1. HRV is a non-invasive method for interpreting autonomic nervous system modulation and provides information relating to each branch of the autonomic nervous system 2. Analysis of the beat to beat variability provides an insight into the relative contributions of the sympathetic and parasympathetic components of the autonomic nervous system’s control of the heart 34. In healthy individuals it is now widely agreed that under normal resting conditions, a high HRV is an indicator that the parasympathetic pathway is dominant over the sympathetic pathway. Consequentially, a large number of various disease states for example, cardiovascular disease have been linked to a low HRV reflecting increased sympathetic activity at rest 5. Studies have reported that regular practice of physical activity improves ...