Endurance-trained athletes have increased heart rate variability (HRV), but it is not known whether exercise training improves the HRV and baroreflex sensitivity (BRS) in sedentary persons. We compared the effects of low- and high-intensity endurance training on resting heart rate, HRV, and BRS. The maximal oxygen uptake and endurance time increased significantly in the high-intensity group com...

BACKGROUND Heart rate variability (HRV) is an established tool for studying cardiac autonomic activity over time, while heart rate turbulence (HRT) is a recent method used to assess autonomic dysfunction. However, there are different autonomic tones at different times of a day. This study aimed to examine the effect of circadian change of autonomic tone on heart rate turbulence and variability,...

Different noninvasive approaches have been developed for risk stratification of patients with myocardial infarction and heart failure with aim to select patients at high risk of sudden cardiac death who might mostly benefit from preventive therapy. Reduced heart rate variability (HRV) was a strong predictor of mortality in myocardial infarction and heart failure in early studies. However, in th...

Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present stud...

Over the last two decades there has been a widespread interest in the study of variations in the beat-to-beat timing of the heart, known as heart rate variability (HRV). The studies of heart rate variability have allowed access to useful information about disturbances in autonomic regulation, which are a promising marker to quantify autonomic activity. Heart rate variability has become the conv...

The heart rate and rhythm are controlled by complex chaotic neural, chemical and hormonal networks which are not strictly regular, but exhibit fluctuations across multiple time scales. A careful assessment of the heart rate variability (HRV) offers clues to this complexity. A reduction in HRV, specifically in advanced age, is associated with increase in morbidity and mortality. Mechanisms that ...

Patients with heart failure or OSA (obstructive sleep apnoea) have reduced HF-HRV (high-frequency heart rate variability), indicating reduced cardiac vagal modulation, a marker of poor prognosis. CPAP (continuous positive airway pressure) abolishes OSA in patients with heart failure, but effects on daytime HF-HRV have not been determined. We hypothesized that, in patients with heart failure, tr...

The analysis of heart rate variability (HRV) has been used as a tool to evaluate the presence of the cardiovascular risks. As described in several studies the psoriasis and cardiovascular risk are strictly related. In our previous study we used the HRV variability for to demonstrate the increase of the cardiovascular risk in the moderate psoriasis. Present study has been designed to test whethe...

Several hamster strains are commonly used as models for cardiomyopathic phenotypes evolving toward heart failure. However, little is known about heart rate variability (HRV) in this species. Prolonged surface ECG recording, a prerequisite to HRV studies, can be obtained either by telemetry or by restraints. Here, we performed long time ECG recording using telemetry on young adult Syrian hamster...

BACKGROUND Pulse wave velocity (PWV) and ankle-brachial pressure index (ABI) are non-invasive tools to measure atherosclerosis and arterial stiffness. Heart rate variability (HRV) has proven to be a non-invasive powerful tool in the investigation of the autonomic cardiovascular control. Therefore, the purpose of this study was to determine the relationship among PWV, ABI, and HRV parameters in ...