Heart rate and its variability - Abstract

The cardiac muscle is privileged, for possessing the capacity to keep its proper rhythm. The heart rate can vary in the dependence of the existing physiological conditions, that is, rest, physical exercise, body position, vigil and sleep state, physical conditioning and pathological conditions. The variation in the cardiac beatings, also call of heart rate variability, is related to the modulation of the sympathetic and nervous parasympathetic system. The study of the heart rate variability, especially in its models of analysis and its clinical application, it still can be valuable in the diagnosis and treatment of complications of the cardiovascular health and, as a complementary tool in the lapsing of physical exercise for sedentary, athlete and heart patients.

The present article aims to present a revision on the study of the heart rate and variability during the rest, the physical exercise and respiratory maneuvers. The methodology of analysis of the heart rate variability is characterized by the initial determination of the period of collection, the instrument, the used stimulaton (physical exercise, respiratory and posture maneuvers) and of the mathematical and statistic models with objective to infer on the sympathetic nervous system and parasympathetic. In such a way, the modifications in the standards of heart rate variability can contribute with one more clinical modality in the identification of the grievance of cardiovascular health.