Background: Patients afflicted with myocardial infarction and hypertension are at increased risk of developing arrhythmias due to autonomic imbalance. Heart rate variability, a non invasive analytical measure, can be employed for evaluating the autonomic nervous system. Cigarette smoking increases the possibility of acute cardiac events associated with augmented sympathetic drive and endothelia...

It is shown that the heart rate variability (HRV) in healthy and diseased humans possesses a hierarchical structure of the She-Leveque (SL) form. This structure, first found in measurements in turbulent fluid flows, implies further details in the HRV multifractal scaling. The potential of diagnosis is also discussed based on the characteristics derived from the SL hierarchy. The heart beat inte...

Pregnancy leads to physiological changes in various parameters of the cardiovascular system. The aim of this study was to investigate longitudinal changes in the structure and complexity of heart rate variability (HRV) and QT interval variability during the second half of normal gestation. We analysed 30-min high-resolution ECGs recorded monthly in 32 pregnant women, starting from the 20th week...

We propose and evaluate an unsupervised method for the estimation of heart rate variability (HRV) indices from ballistocardiograms (BCGs) recorded by a bed-mounted, electromechanical film (EMFi) sensor during sleep. After estimating the beat-to-beat intervals from the BCGs, short-term timeand frequency-domain HRV indices are computed and compared to an ECG reference. We evaluated signals record...

Physical inactivity and low resting heart rate variability (HRV) are associated with increased coronary heart disease incidence. In the Whitehall II study of civil servants aged 45-68 years (London, United Kingdom, 1997-1999), the strength of the association of moderate and vigorous activity with higher HRV was examined. Five-minute recordings of heart rate and HRV measures were obtained from 3...

BACKGROUND Since heart rate variability (HRV) is associated with average heart rate (HR) and respiratory rate (RespRate), alterations in these parameters may impose changes in HRV. Hence the repeatability of HRV measurements may be affected by differences in HR and RespRate. The study aimed to evaluate HRV repeatability and its association with changes in HR and RespRate. METHODS Forty health...

It remains unclear if diminished high frequency heart rate variability (HF-HRV) can be found across anxiety disorders. HF-HRV and heart rate (HR) were examined in panic (PD), generalized anxiety (GAD), social anxiety (SAD), and obsessive-compulsive disorder (OCD) relative to healthy controls at baseline and during anxiety stressors. All disorders evidenced diminished baseline HF-HRV relative to...

The heart rate variability (HRV) signal carries important information about the systems controlling the heat rate, mainly elicited by autonomic nervous system (sympathetic and parasympathetic) controls. The analysis of HRV signal with existing linear techniques based on fast Fourier transform and autoregressive model have the disadvantages of lower sensitivity and positive predictive value of <...

Heart rate variability (HRV) is the result of variation in time between two successive heart beats. HRV is the tool for investigation of healthy and diseased condition. It also reflects an influence of autonomic nervous system on function of heart. In this study, our aim is to distinguish normal sinus rhythm from atrial fibrillation and Supraventricular arrhythmia. Here the ECG signal is pre-pr...

In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years...