The development of sympatho-vagal control of cardiac activity was analyzed in zebrafish (Danio rerio) larvae from 2 to 15 days post fertilization (d.p.f.) by pharmacological studies as well as by assessing short term heart rate variability. Changes in heart rate in response to cholinergic and adrenergic receptor stimulation or inhibition were investigated using in situ preparations and digital ...

BACKGROUND Reduced heart rate variability is associated with an unfavorable prognosis in patients with ischemic heart disease and diabetes. Whether change in breathing pattern can modify the risk factor in these patients has not been definitely proved. OBJECTIVE To evaluate the effect of diaphragmatic breathing on heart rate variability (HRV) in ischemic heart disease patients with diabetes. ...

Although physiological (e.g., exercise) and pathological (e.g., infection) stress affecting the cardiovascular system have both been documented to be associated with a reduction in overall heart rate variability (HRV), it remains unclear if loss of HRV is ubiquitously similar across different domains of variability analysis or if distinct patterns of altered HRV exist depending on the stressor....

Autonomic nervous system (ANS) dysregulation in depression is associated with symptoms associated with the ANS. The beat-to-beat pattern of heart rate defined as heart rate variability (HRV) provides a noninvasive portal to ANS function and has been proposed to represent a means of quantifying resting vagal tone. We quantified HRV in bipolar depressed (BDD) patients as a measure of ANS dysregul...

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...