Results 261 to 270 of about 820,034 (298)
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Heart rate variability in pheochromocytoma
The American Journal of Cardiology, 1995The results of our study show that parasympathetic tone was higher in patients with pheochromocytoma than in patients with primary hypertension. An unusual spectral form of vagal activity was seen during excessive beta-adrenergic stimulation, while persistent hypertension with an excessive alpha-adrenergic stimulation was responsible for low cardiac ...
B, Dabrowska +4 more
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Migraine and Heart Rate Variability
Archives of Internal Medicine, 2007We report preliminary data from our study showing the presence of cardiac autonomic dysfunction in subjects with migraine. A total of 28 subjects (18 women and 10 men; mean±SD age, 36±4.2 years) with active migraine with aura, diagnosed according to criteria of the International Headache Society, were enrolled.The data show that subjects with active ...
PERCIACCANTE A +4 more
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Heart Rate Variability in Athletes
Sports Medicine, 2003This review examines the influence on heart rate variability (HRV) indices in athletes from training status, different types of exercise training, sex and ageing, presented from both cross-sectional and longitudinal studies. The predictability of HRV in over-training, athletic condition and athletic performance is also included.
André E, Aubert +2 more
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Thermoregulation and Heart Rate Variability
Clinical Science, 19961. Heart rate variability is modulated by multiple control systems, including autonomic and hormonal systems. Long-term variability, i.e. the very low-frequency band of the power spectra, has been postulated to reflect thermoregulatory vasomotor control, based upon thermal entrainment experiments.
L A, Fleisher +5 more
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Multifractality and heart rate variability
Chaos: An Interdisciplinary Journal of Nonlinear Science, 2009In this paper, we participate to the discussion set forth by the editor of Chaos for the controversy, “Is the normal heart rate chaotic?” Our objective was to debate the question, “Is there some more appropriate term to characterize the heart rate variability (HRV) fluctuations?” We focused on the ≈24 h RR series prepared for this topic and tried to ...
Sassi R. +2 more
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Measurement of Heart Rate Variability
Western Journal of Nursing Research, 1995Heart rate variability (HRV) is a measure of autonomic nervous system balance/imbalance. Measurement and analysis of HRV can be classified into time domain analysis and frequency domain analysis. lime domain analysis is a general measure of autonomic nervous system balance and is based on altered versions of the measurement of the standard deviation of
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Heart rate variability and sports
Human Physiology, 2016The article presents a review of the literature and some of their own data on the problem of the possibilities of using the method of the study of heart rate variability in the practice of sports and sports Miedicine.
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Analysis of Heart Rate Variability
Ergonomics, 1973Spontaneous variability of heart-rate has been related to three major physiological originating factors: quasi-oscillatory fluctuations thought to arise in blood-pressure control, variable frequency oscillations due to thermal regulation, and respiration; frequency selective analysis of cardiac interbeat interval sequences allows the separate ...
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The Effects of Specific Respiratory Rates on Heart Rate and Heart Rate Variability
Applied Psychophysiology and Biofeedback, 2003In this study respiratory rates of 3, 4, 6, 8, 10, 12, and 14 breaths per minute were employed to investigate the effects of these rates on heart rate variability (HRV). Data were collected 16 times at each respiratory rate on 3 female volunteers, and 12 times on 2 female volunteers.
Hye-Sue, Song, Paul M, Lehrer
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Heart rate variability in neurosurgical patients
Neurosurgery, 1986Cardiac monitors determine heart rate by counting the number of beats in a given time interval. The normal heart, however, does not beat at a constant rate. Instead, there is a continuous change in heart rate on a beat-by-beat basis. This is termed the instantaneous heart rate and it represents the projected rate per minute that the heart would beat if
T J, Leipzig, R I, Lowensohn
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