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LF/HF Values (hf + value)

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Medical Sciences	100%

Selected Abstracts

Asymptomatic leukocyturia and the autonomic nervous system in women

GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2 2009
Yoshimasa Igari
Background: The present study sought to investigate the relationship between asymptomatic leukocyturia (ASL) and autonomic nervous function by power spectral analysis of the R-R intervals in women. Methods: One hundred and forty-two female outpatients aged 23,91 years were studied. We regarded ASL to be present if two consecutive samples were found to have 10 or more leukocytes/high-power field at ×400 magnification in a centrifuged midstream urine sample. The R-R intervals of all subjects were measured by the wavelet transform analysis system. This system detected R-R variation data distributed in two bands: low-frequency power (LF) (0.04,0.15 Hz) and high-frequency power (HF) (0.15,0.40 Hz). The ratio of LF to HF (LF/HF) was also determined. Post-void residual urine volume was measured using an automated, compact 3-D ultrasound device. Results: The patients with ASL had diabetes mellitus more frequently than those without ASL. Residual urine volume was significantly higher in the former than in the latter, while the HF values in both a recumbent position and a standing position were significantly lower in the former than in the latter (P = 0.003, P = 0.001, respectively). However, there were no significant differences in LF or LF/HF values in either a recumbent or a standing position between the two groups. The HF values in both a recumbent position and in a standing position were independent indicators of ASL, even after adjustment for age, diabetes mellitus and residual urine volume. Conclusion: The present study reveals the relationship between ASL and impairment of the parasympathetic nervous system in women. [source]

Autonomic dysfunction in unselected and untreated primary open angle glaucoma patients: a pilot study

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2007
Doina Gherghel
Abstract Purpose:, To investigate the presence of silent cardiac ischaemic episodes and the status of autonomic function in consecutive, newly diagnosed and untreated primary open-angle glaucoma patients. Methods:, Twenty-four consecutively diagnosed glaucoma patients and 22 age-matched controls were subjected to ambulatory 24-h blood pressure (BP) and electrocardiogram (ECG) monitoring by using Cardiotens-01 (Meditech Ltd). Based on the ECG recordings, heart rate variability (HRV) frequency domain parameters [low-frequency (LF), high-frequency (HF) and LF/HF ratio] were calculated and analysed in the two study groups. Results:, Glaucoma patients demonstrated higher LF and LF/HF values than normal subjects for both the active period (p = 0.020 and 0.029) and the passive period (p = 0.044 and 0.049 respectively). HRV parameters were similar in patients and controls suffering from silent cardiac ischaemia (p > 0.05); however, glaucoma patients with normal ECG demonstrated higher LF and LF/HF values during the active period of the 24-h measurement period than control subjects characterized by the same cardiac activity (p = 0.010 and 0.021 respectively). Conclusion:, Independent of a history and/or clinical signs of cardiovascular disease, glaucoma patients exhibit abnormal autonomic function. [source]

2357: Autonomic nervous system and endothelial peripheral dysfunction in normal tension glaucoma patients

ACTA OPHTHALMOLOGICA, Issue 2010
J WIERZBOWSKA
Purpose To define parameters of autonomic nervous system activity and peripheral vascular reactive hyperemia in normal tension glaucoma patients. Methods Ambulatory 24-hour electrocardiogram and blood pressure (BP) monitoring by using Lifecard CF and SpaceLab 90207-30 combined with occlusion provocation test were carried out in 54 NTG patients (44 women, mean age 59.7) and 43 matched control subjects (34 women, mean age 57.0). Heart rate variability (HRV) time and frequency domain parameters [low-frequency (LF), high-frequency (HR) and LF/HF ratio], and blood pressure variability (BPV) were calculated and analyzed for both study groups. Postocclusive hyperemia response parameters (TM - time to peak flow, TH ,half-time hyperaemia, TR ,time to rest flow, BZ-biological zero and MAX , maximum hyperemic response) were compared for patients with a nocturnal fall in mean BP (MPB) of less than 10% (non-dippers), of 10-20% (dippers) and of more than 20% (over-dippers) Results NTG patients demonstrated higher LF and LF/HF values for 24-hour period, day-time and night time than control subjects. There was no difference in BPV between study groups (10.4 ± 1.9 vs. 10.5 ± 2.1, p=0.790). In NTG patients, TH was significantly higher (79.0 ± 80.9 s vs. 51.5 ± 35.3 s, p=0.028) and BZ was significantly lower (2.3 ± 1.0 vs. 3.1 ± 2.0, p=0.009) as compared to the control group. There was statistically significant difference between NTG non-dippers, dippers and over,dippers in the BZ parameter (2.3 ± 0.9 vs. 2.7 ± 1.3 vs. 1.4 ± 0.4 p=0.024). Conclusion NTG patients exhibit abnormal ANS system activity and a different systemic hyperemia response as compared with healthy subjects. [source]