Clinical relevance of heart rate variability

2009

Among the techniques used in its evaluation, the heart rate variability (HRV) has arising as a simple and non-invasive measure of the autonomic impulses, representing one of the most promising quantitative markers of the autonomic balance. The HRV describes the oscillations in the interval between consecutive heart beats (RR interval), as well as the oscillations between consecutive instantaneous heart rates. It is a measure that can be used to assess the ANS modulation under physiological conditions, such as wakefulness and sleep conditions, different body positions, physical training and also pathological conditions. Changes in the HRV patterns provide a sensible and advanced indicator of health involvements. Higher HRV is a signal of good adaptation and characterizes a health person with efficient autonomic mechanisms, while lower HRV is frequently an indicator of abnormal and insufficient adaptation of the ANS, provoking poor patient's physiological function. Because of its importance as a marker that reflects the autonomic nervous system activity on the sinus node and as a clinical instrument to assess and identify health involvements, this study reviews conceptual aspects of the HRV, measurement devices, filtering methods, indexes used in the HRV analyses, limitations in the use and clinical applications of the HRV.

MGM Journal of Medical Sciences, 2016

Heart rate variability (HRV) came into existence by observations of Hon and Lee in 1965 and since then has been a subject of prime importance in medical research. It is derived from changes in RR intervals in a continuous recording of electrocardiogram. Different types of measurements are carried out on these RR intervals in time and frequency domain. Among others, variance, total power, low-frequency (LF) power, high-frequency (HF) power, and LF/HF ratio are frequently used HRV parameters for objective assessment of autonomic function and assessment of several clinical conditions. Poincare plot gives a quick visual impression of HRV. This article describes measurement of all these parameters and their clinical applications.

Frontiers in physiology, 2015

Annals of Noninvasive Electrocardiology, 2005

Electrocardiographic RR intervals fluctuate cyclically, modulated by ventilation, baroreflexes, and other genetic and environmental factors that are mediated through the autonomic nervous system. Short term electrocardiographic recordings (5 to 15 minutes), made under controlled conditions, e.g., lying supine or standing or tilted upright can elucidate physiologic, pharmacologic, or pathologic changes in autonomic nervous system function. Long-term, usually 24-hour recordings, can be used to assess autonomic nervous responses during normal daily activities in health, disease, and in response to therapeutic interventions, e.g., exercise or drugs. RR interval variability is useful for assessing risk of cardiovascular death or arrhythmic events, especially when combined with other tests, e.g., left ventricular ejection fraction or ventricular arrhythmias. A.N.E. 2005;10(1):88-101 autonomic nervous system Address for reprints: J. Thomas Bigger, Jr., M.D.

Journal of Integrative Cardiology

The heart rate variability (HRV), which can provide information about the balance between the sympathetic and the parasympathetic system, is accepted as an indicator of autonomic tone, which is effective on the heart. Neural remodeling developing in hearts that are affected by various diseases leads to imbalance in the autonomic activity. These changes that may occur in the autonomic nervous system may lead to ventricular arrhythmia and sudden cardiac death through negatively affecting the cardiac rhythm. HRV has been evaluated in many cardiac, neurological and rheumatological diseases in recent years and has come into the foreground as an important marker of mortality. In this review, we aimed to introduce the parameters used in HRV measurements and analyze the conditions that could influence these measurements (maneuver, diseases or drugs, etc).

Journal of the Autonomic Nervous System, 1990

Clinical interest in HRV was sparked by the 1973 report of Wheeler and Watking, who first drew attention to cardiac vagal innervations as the mediation of HRV and its potential value as a clinical test of cardiovascular function HRV varies with age, gender, cardiac diseases, nutritional status with different drugs and in response to a number of other factors, such as diabetic autonomic neuropathy. In addition gender has a strong influence on mechanism on HRV. However the influence of gender and the underlying mechanisms has not yet been determined, till date no work has been conducted to understand the role of gender on HRV. This is a cross sectional study conducted in Jan-March 2010 with a sample size of 86 (43 male, 43 Female) was calculated based on the results of a study done on similar subjects. The temperature of the laboratory was kept between 25 o c-28 o c and lights subdued. The subjects were asked to void urine before testing and made to sit in the lab comfortably to accustom to the new environment. ECG electrodes were connected for lead II. Baseline Heart Rate and Blood Pressure were recorded. Then at supine rest with the eyes closed and relaxed position, lead II ECG was acquired at the rate of 200 samples/second for 10minutes with the normal breath rate of 12-18/min using RMS Polyrite D hardware, INDIA, which is the data acquisition system. There was no significant difference in time domain measures of HRV in between male and females. But in frequency domain analysis Higher LF power, TP, LF/HF ratio and Lower LF values is seen in females.

Journal of The American College of Cardiology, 1999

The objectives of this review are to discuss the diversity of mechanisms that may explain the association between heart rate (HR) variability and mortality, to appraise the clinical applicability of traditional and new measures of HR variability and to propose future directions in this field of research.

Scandinavian Journal of Work, Environment & Health, 1995

Indian pacing and electrophysiology journal, 2003

Autonomic nervous system plays an integral role in homeostasis. Autonomic modulation can frequently be altered in patients with cardiac disorders as well as in patients with other critical illnesses or injuries. Assessment of heart rate variability is based on analysis of consecutive normal R-R intervals and may provide quantitative information on the modulation of cardiac vagal and sympathetic nerve input. The hypothesis that depressed heart rate variability may occur over a broad range of illness and injury, and may inversely correlated with disease severity and outcome has been tested in various clinical settings over the last decade. This article reviews recent literature concerning the potential clinical implications and limitations of heart rate variability assessment in general medicine.