scholarly journals Power Spectral Analysis of Heart Rate Variability In Hypothyroidism

1970 ◽  
Vol 5 (2) ◽  
pp. 53-59 ◽  
Author(s):  
Matia Ahmed ◽  
Noorzahan Begum ◽  
Sultana Ferdousi ◽  
Shelina Begum ◽  
Taskina Ali
Keyword(s):  
Spectral Analysis ◽  
Nervous Activity ◽  
Power Spectral Analysis ◽  
Autonomic Nervous Activity ◽  
Mean Values ◽  
Power Spectral ◽  
Group A ◽  
The Mean ◽  
Hypothyroid Patients ◽  
Serum Tsh

Background: Hypothyroidism is one of the common clinical problems with high incidence in women particularly in older age. It has profound effect on metabolic processes in almost all tissue of the body and heart is particularly sensitive to thyroid hormone action. Power spectral analysis (PSA)is useful to determine the cardiac autonomic regulation by assessing sympathovagal balance. Objectives: To assess the cardiac autonomic nervous activity by power spectral analysis of heart rate variability in patients with hypothyroidism.Method: This cross sectional study was carried out in the Department of Physiology, Banghabandhu Sheikh Mujib Medical University from 1st July 2008 to 30th June 2009 on 60 female patients of 30-50 years with hypothyroidism (group B). For comparison, 30 age sex matched apparently healthy euthyroid subjects (group A) were also studied. Based on treatment, hypothyroid patients were divided into B1 (patients on their 1st day of diagnosis, before starting of treatment) and B2 (patients with medication for 12-18 months). The patients were selected from the Out Patients Department of Endocrinology, BSMMU. Serum TSH and FT4 levels of all subjects were measured by AxSYM system. To perform power spectral analysis of HRV Total Power (TP), Low Frequency (LF), High Frequency (HF), LF norms (nu), HF norms (nu) and LF/HF ratio were assessed by a Polyrite. For statistical analysis of data, Independent Sample t test, One Way ANOVA and Pearson’s correlation coefficient test were done as applicable.Results: The mean serum TSH (38.16 vs2.18; 2.04) was significantly higher and FT4 (5.12vs 15.13; 15.08) was significantly lower (p<0.001) in group B1 than those of group A and B2. The mean values of all the spectral parameters of HRV in euthyroid subjects were within normal range. In untreated hypothyroid patients the mean values of TP (77.11vs2702.87; 2683.73), HF power (56.68 vs 342.02; 437.34) HF nu (24.79 vs 36.35; 34.55) were found significantly (p<0.001) lower LF/HF (1.7±0.3,3.16±.84 and 1.93±.58) and LF nu (75.32 vs 63.71, and 65.90) were significantly (p<0.001) higher and in comparison to both euthyroids and treated patients. Conclusion: Alteration in cardiac autonomic nervous activity characterized by reduced vagal modulation and higher sympathetic activity may occur in the hypothyroid patients.Keywords: HRV; LF HF LF/HF Hypothyroidism DOI: 10.3329/jbsp.v5i2.6777J Bangladesh Soc Physiol. 2010 December; 5(2): 53-59

Detection of a biorhythm of human fetal autonomic nervous activity by a power spectral analysis

2001 ◽  
Vol 185 (5) ◽  
pp. 1247-1252 ◽  
Author(s):  
Toshiaki Suzuki ◽  
Yoshitaka Kimura ◽  
Jun Murotsuki ◽  
Takashi Murakami ◽  
Shigeki Uehara ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Nervous Activity ◽  
Power Spectral Analysis ◽  
Autonomic Nervous Activity ◽  
Autonomic Nervous ◽  
Power Spectral

scholarly journals Power spectral analysis of heart rate variability in Bangladeshi healthy population of different age

2014 ◽  
Vol 30 (1) ◽  
pp. 11-15
Author(s):  
Qazi Farzana Akhter ◽  
Qazi Shamima Akhter ◽  
Farhana Rahman ◽  
Sybyla Ferdousi ◽  
Susmita Sinha
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Power Spectral Analysis ◽  
Autonomic Nerve ◽  
Total Power ◽  
Healthy Population ◽  
Cross Sectional ◽  
Power Spectral ◽  
Group A

Heart rate variability (HRV) has been considered as an indicator of autonomic nerve function status. We aimed to find out the reference values of heart rate variability by power spectral analysis in our healthy population of different age. This cross sectional study was conducted in the Department of Physiology, Dhaka Medical College, Dhaka from the period of July 2012 to June 2013. For this, 180 subjects were selected with the age ranging from 15-60 years. All the study subjects were divided into 3 different groups according to age (Group A: 15-30 years; Group B: 31-45 years; Group C: 46-60 years). Each group contained 60 subjects of which 30 were male and 30 were female. The subjects were selected from different areas of Dhaka city by personal contacts. Analysis of HRV parameters were done in Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka. For statistical analysis, one way ANOVA, unpaired Students t-test and Pearson’s correlation coefficient test were performed by using SPSS (version-17) as applicable. LF nu, LF power and LF/HF were significantly (p<0.001) higher in group C in comparison to those of group A and B. Again Total power, HF power, HF nu (p<0.001) were significantly higher in group A and B in comparison to that of group C. This study concludes that cardiac parasympathetic activity was decreased and sympathetic activity was increased with aging.DOI: http://dx.doi.org/10.3329/bjpp.v30i1.20788 Bangladesh J Physiol Pharmacol 2014; 30(1):11-15

scholarly journals Power spectral analysis of heart rate in hypothyroidism

2000 ◽  
pp. 327-333 ◽  
Author(s):  
V Cacciatori ◽  
ML Gemma ◽  
F Bellavere ◽  
R Castello ◽  
ME De Gregori ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Spectral Density ◽  
Cardiovascular System ◽  
Power Spectral Density ◽  
Power Spectral Analysis ◽  
Control Subjects ◽  
Power Spectral ◽  
Hypothyroid Patients

OBJECTIVE: The aim of the present study was to evaluate the impact of hypothyroidism on the autonomic regulation of the cardiovascular system by analysing separately sympathetic and parasympathetic influences on the heart. DESIGN: In seven newly diagnosed untreated hypothyroid patients we analysed power spectral density of heart rate cyclic variations at rest, while lying, and while standing. The same protocol was repeated after the induction of stable euthyroidism by levothyroxine (L-T(4)) treatment. The results were also compared with those obtained from seven age-, sex- and body mass index-matched control subjects. METHODS: Heart rate variability was evaluated by autoregressive power spectral analysis (PSA). This method allows reliable quantification of low frequency (LF) and high frequency (HF) components of the heart rate power spectral density. These are considered to be under mainly sympathetic and purely parasympathetic control respectively. In addition, heart rate variations during deep breathing, lying to standing, and Valsalva's manoeuvre were assessed. RESULTS: PSA showed a sharp reduction in the HF (parasympathetic) component in hypothyroid subjects compared with controls (lying, 29.4+/-5.4 vs 47.7+/-6.3 normalized units (NU) (means +/- s.e.m.), P<0.05; standing, 14.0+/-3.5 vs 32.1+/-3.6NU, P<0.005). Conversely, the LF (mainly sympathetic) component was higher in hypothyroid subjects than in controls (lying, 61.6+/-6.4 vs 45.4+/-6.7 NU; standing, 71.7+/-8.0 vs 53.1+/-5.6NU), this difference being significant in the standing position. Hence, the LF/HF ratio, which is considered an index of sympathovagal balance, was increased in hypothyroid subjects while both lying (2.75+/-0.6 vs 1.16+/-0.3; P<0.05) and standing (10.0+/-3.7 vs 1.85+/-0.3; P<0. 02). Total heart rate variability, expressed as total power spectral density, was lower in hypothyroid patients than in control subjects, this difference being significant in the lying position (574+/-126 vs 2302+/-994ms(2), P<0.05). In patients re-examined after L-T(4) therapy, complete normalization of cardiovascular parameters was observed (LF/HF ratio, lying, 1.26+/-0.4; standing, 2.56+/-0.8, both P<0.01 vs baseline values). The response to conventional cardiovascular autonomic tests was not significantly different between hypothyroid patients and healthy controls, and did not change in patients after therapy. CONCLUSIONS: These results suggest that, contrary to the clinical picture, thyroid hormone deficiency is associated with an increased sympathetic influence on the autonomic cardiovascular system. The changes in sympathetic function could be explained by a secondary adaptation to an altered cardiovascular responsiveness.

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