.../mmHg as a cut-off value that is the identifier of a homogeneous group of patients with depressed BRS, and highlights the robustness of this threshold in risk stratification due to its age-independent prognostic value. ageing heart failure (HF) risk stratification spectral analysis spontaneous...

...-spectral analysis fell in the patients to approx. one-third of the sensitivity estimated in the healthy controls whatever the position. This cardiovascular profile suggests a predominant vagal dysfunction with signs of vagal withdrawal and baroreflex failure, and relative preservation of the cardiac...

... autonomic nervous system heart failure heart rate variability spectral analysis For more than two decades short-term power spectral analysis of HRV [HR (heart rate) variability] has been used to assess autonomic control of HR. Recently, it has also been used to stratify the risk of sudden death...

...-term spectral analysis to evaluate autonomic control in subjects with recurrent vasovagal syncope. We assessed the ability of spectral indices of HR (heart rate) variability to predict tilt-test responses. A series of 47 outpatients with recurrent vasovagal syncope and with positive responses to head...

... 18 4 2002 The Biochemical Society and the Medical Research Society © 2002 2002 baroreflex sensitivity cardiovascular variability coherence phenylephrine test spectral analysis transfer function. 81Clinical Science (2002) 103, 81 88 (Printed in Great Britain) Measuring baroreflex...

... portal hypertension spectral analysis systemic haemodynamics transcranial Doppler. 43Clinical Science (2002) 103, 43 51 (Printed in Great Britain) Impaired sympathetic regulation of cerebral blood flow in patients with cirrhosis of the liver Alfonso LAGI*, Giacomo LAFFI , Simone CENCETTI*, Giuseppe...

..., but the need for drug injection limits the use of this technique. Recently, several non-invasive methods based on spectral analysis of systolic arterial pressure and heart period have been proposed, but their agreement with the phenylephrine test has not been investigated in patients with heart failure...

...C. ZAMARRÓN; P. V. ROMERO; J. R. RODRIGUEZ; F. GUDE Using spectral analysis of oximetry data, we prospectively evaluated the validity of this methodology in patients clinically suspected of suffering from obstructive sleep apnoea (OSA). A total of 233 outpatients were studied. Nocturnal oximetry...

... of this α-adrenoceptor agonist. Blood pressure levels were normal and head-up tilt did not induce orthostatic hypotension in this moderate form of GBS. Power spectral analysis demonstrated marked alterations in cardiovascular variability. The overall heart period variability was markedly reduced...

...Catherine F. NOTARIUS; Gary C. BUTLER; Shin-ichi ANDO; Michael J. POLLARD; Beverley L. SENN; John S. FLORAS The concept that spectral analysis of heart rate variability (HRV) can estimate cardiac sympathetic nerve traffic in subjects with both normal and impaired left ventricular systolic function...

... 1998 15 7 1998 5 8 1998 The Biochemical Society and the Medical Research Society © 1999 1999 intradialytic hypotension spectral analysis sympathetic activity 23Clinical Science (1999) 96, 23 31 (Printed in Great Britain) Impaired sympathetic response before intradialytic...

... period were analysed using fractal dimensions, approximate entropies and spectral analysis for the quantification of absolute and relative heart period variability in bands of ultra low (< 0.0033 ;Hz), very low (0.0033–0.04 ;Hz), low (0.04–0.15 ;Hz) and high (0.15–0.5 ;Hz) frequency. 3. Linear...

... to physiological man- Key words: cardiovascular autonomic function, diabetes mellitus, rn231]iodobenzylguanidine, heart rate, QT interval, single-photon emission computed tomography, spectral analysis. Abbreviations: CAN, cardiomcular autonomic neuropathy; I-MIBG, rn231]iodobenzylguanidine; ROI, region of interest...

... components as nor- malized units, and use of a cross-over design, mini- mize the number of subjects to be included in clinical studies conducted using similar designs and LF component changes as endpoints. INTRODUCTION Power spectral analysis of systolic blood pressure (SBP) and heart rate (HR) variability...

...Cornelius Keyl; Peter Lemberger; Michael Pfeifer; Karin Hochmuth; Peter Geisler 1. Periodic breathing is known to be associated with cyclic fluctuations in heart rate. The purpose of this study was to evaluate the capability of spectral analysis of heart rate variability to identify episodes...

... of human subjects. In the first protocol, core temperature was reduced by intravenous infusion of cold saline, while skin temperature was unchanged. The second protocol involved skin-surface warming and cooling until shivering developed. Power spectral analysis was performed using a fast Fourier...

... effectors rather than the vagus. © 1995 The Biochemical Society and the Medical Research Society 1995 autonomous nervous system blood pressure heart rate heart transplantation spectral analysis tilt variability Clinical Science (1995) 88, 95-102 (Printed in Great Britain) 95 Spectral...

.... The effect of head-down tilt on finger blood pressure and heart rate fluctuations was studied by means of power spectral analysis in 12 healthy men. 2. Amplitude spectra of heart rate and blood pressure rhythmicity were estimated at the low-frequency (60–140 mHz, 10-s rhythm) and high-frequency (area under...

... as a functional correlate. 2. Autoregressive spectral analysis of R-R interval variability from a surface ECG, was used in healthy control subjects ( n = 24, age 45 ± 4 years) and in subjects complaining of unexplained fatigue ( n = 53, age 46 ± 9 years) to obtain quantitative indices of the state...

... variability spectral analysis, the cardiac autonomic effects of breathing 30% N20 in normal subjects. While supine, the inhalation of N20 caused a significant fall in high-frequency power and a rise in the low-/high- frequency spectrum. During air breathing, tilting caused a significant rise in the mean blood...

..., a new method of computerized analysis of respiratory sinus arrhythmia based on spectral analysis of electrocardiographic and respiratory signals. 3. Considering tests indicative of parasympathetic function, only the heart rate response to the deep breathing and the cross-correlation test were...