Heart rate variability (HRV) is the present oscillation of the heart rate. The interest in HRV as a parameter of the parasympathetic and sympathetic influence of the autonomic nervous system on the heart has increased in the last few decades (Kaikkonen et al., 2007). It is known that its influence changes under different conditions such as rest, exercise or mental stress and different body post...

Objectives. The purpose of this study was to assess the heart rate variability (HRV) during off-snow and on-snow training in an elite female alpine ski racer. Methods. Using a case study design, a single elite female alpine ski racer (25 years old; 175.6 cm; 69.9 kg) was recruited from the Canadian Alpine Ski Team. Training load was obtained using the sessional rating of perceived exertion met...

electrocardiogram (ecg) is one of the most common biological signals which plays a significant role in diagnosis of heart diseases. one of the most important parts of ecg signal processing is interpretation of qrs complex and obtaining its characteristics. r wave is one of the most important sections of this complex which has an essential role in diagnosis of heart rhythm irregularities and als...

Heart Rate Variability (HRV) series exhibit long memory and time-varying conditional variance. This work considers the Fractionally Integrated AutoRegressive Moving Average (ARFIMA) models with Generalized AutoRegressive Conditional Heteroscedastic (GARCH) errors. ARFIMA-GARCH models may be used to capture and remove long memory and estimate the conditional volatility in 24 h HRV recordings. Th...

The objective of this study was to compare linear and non-linear analysis of heart rate variability (HRV) in terms of correlation with haemodynamic fluctuation during induction of general anaesthesia. Pre-operatively, HRV was estimated by the MemCalc method in 114 patients scheduled for general anaesthesia. After anaesthesia was induced with propofol, fentanyl and vecuronium bromide, tracheal i...

OBJECTIVE Monitoring of the fetal condition during labor is currently performed by cardiotocograpy (CTG). Despite the use of CTG in clinical practice, CTG interpretation suffers from a high inter- and intra-observer variability and a low specificity. In addition to CTG, analysis of fetal heart rate variability (HRV) has been shown to provide information on fetal distress. However, fetal HRV can...

It is assumed that the low-frequency power (LF) of heart rate variability (HRV) increases with progress of congestive heart failure (CHF), therefore positively correlating with cardiac 123I-metaiodobenzylguanidine (MIBG) washout. It is demonstrated here that HRV, including normalized LF, correlated inversely with MIBG washout and positively with the ratio of heart-to-mediastinum MIBG activity i...

Heart rate variability (HRV) is an important measure of sympathetic and parasympathetic functions of the autonomic nervous system and a key indicator of cardiovascular condition. This paper proposes a novel method to investigate HRV, namely by modelling it as a linear combination of Gaussians. Results show that three Gaussians are enough to describe the stationary statistics of heart variabilit...

Context: Previous studies reported decreased heart rate variability (HRV) among subjects with anemia. However, the underlying pathology of anemia may be the direct cause of low HRV which may preclude from drawing the conclusion that anemia per se causes diminished HRV. Aim: To detect the relationship between hemoglobin concentrations and HRV. Setting and Design: It was a cross-sectional case-co...