Linear and nonlinear heart rate variability indexes in clinical practice (Q764132)

Summary: Biological organisms have intrinsic control systems that act in response to internal and external stimuli maintaining homeostasis. The human heart rate is not regular and varies in time and such variability, also known as heart rate variability (HRV), is not random. HRV depends upon the organism's physiologic and/or pathologic state. Physicians are always interested in predicting patient's risk of developing major and life-threatening complications. Understanding biological signals behavior helps to characterize patient's state and might represent a step toward a better care. The main advantage of signals, such as HRV indexes, is that they can be calculated in real time in a noninvasive manner, while all current biomarkers used in clinical practice are discrete and imply blood sample analyses. In this paper, HRV linear and nonlinear indexes are reviewed and data from real patients are provided to show how these indexes might be used in clinical practice.