Heart Rate Variability in Hyperthyroidism

Background: Hyperthyroidism is associated with altered cardiac autonomic nervous activity (CANA). Heart Rate Variability (HRV) analysis is a promising technique to quantify CANA and therefore can be done in hyperthyroidism. Objective: To observe the HRV parameters in patients with hyperthyroidism to find out the influence of excess thyroid hormone on cardiac autonomic nervous activities. Method: The cross sectional study was carried out on 60 hyperthyroid patients (groupB) aged 30-50 years in the Department of Physiology, BSMMU, Dhaka from 1st July 2007 to 30th June 2008. Age and sex matched 20 apparently healthy euthyroids were also studied for comparison (group A). On the basis of treatment, they were further divided into group B1 consisting of 30 untreated newly diagnosed patients and group B2 consisting of 30 hyperthyroid patients treated with antithyroid drugs for at least 2 months. The patients were selected from the Out Patient Department of Endocrinology, BSMMU, Dhaka. To assess thyroid status, serum TSH and serum FT4 levels were measured by AxSym system and time domain measures of HRV such as mean R-R interval, mean heart rate, SDNN and RMSSD were assessed from 5 minute (short term) ECG recording by a polygraph. For statistical analysis Mann-Whitney U test was done. Results: Mean R-R interval was significantly (P<0.001) lower but mean heart rate was significantly (P<0.001) higher in untreated patients than those of treated and euthyroids subjects. These values were found almost similar when compared between euthyroids and treated hyperthyroids. Similarly SDNN and RMSSD were significantly lower in untreated hyperthyroids than both euthyroids (P<0.001) and treated hyperthyroids (P<0.01). Conclusion: This study concluded that decreased vagal modulation on heart rate may occur in hyperthyroidism, which may be restored following adequate treatment of the disease. Keywords: HRV, R-R Interval, Heart rate, RMSSD, Hyperthyrodism DOI: 10.3329/jbsp.v4i2.4172 J Bangladesh Soc Physiol. 2009 Dec;4(2): 51-57

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Relationship of Thyroid Hormones with Heart Rate Variability

Journal of Bangladesh Society of Physiologist ◽

10.3329/jbsp.v5i1.5414 ◽

1970 ◽

Vol 5 (1) ◽

pp. 20-26

Author(s):

Rassel Kabir ◽

Noorzahan Begum ◽

Sultana Ferdousi ◽

Shelina Begum ◽

Taskina Ali

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Negative Correlation ◽

Nervous Activity ◽

Antithyroid Drugs ◽

Cross Sectional ◽

Rr Interval ◽

Group A ◽

Serum Tsh ◽

Mean Heart Rate

Background: Altered thyroid functions are associated with variation in autonomic regulation ofcardiovascular activity. Cardiac Autonomic Nervous Activity (CANA) can be assessed quantitativelyby analysis of Heart Rate Variability (HRV). Objective: To observe the relationship between CANAwith altered TSH and FT4. Methods: This cross sectional study was carried out in the Department ofPhysiology, BSMMU, Dhaka between1st July 2007 and 30th June 2008 on 60 patients with excessthyroid hormone (group B, aged 30-50 years). Based on treatment, 30 untreated newly diagnosedpatients were designated as group B1 and 30 patients under treatment with antithyroid drugs for atleast 2 months were included into group B2 in order to observe the effect of treatment. All thesepatients were selected from the Out Patient Department of Endocrinology wing of Department ofMedicine, BSMMU, Dhaka. Sociodemographically matched 20 apparently healthy euthyroid personswere selected for comparison (group A). To confirm thyroid status, serum TSH and serum FT4 levelswere measured by AxSym system and some of the spectral HRV parameters i.e.mean R-R interval,mean heart rate, variance, LF n.u, HF n.u and LF/HF ratio were assessed by recordings of ECG for 5minute (short term) with a polyrite. For statistical analysis Pearson’s correlation coefficient (r) test wasused. Results: With serum TSH level, the LF n.u. power and LF/HF ratio showed significant (p<0.05)positive correlations but HF n.u. power showed significant (p<0.05) negative correlation in group B1.But these three parameters showed non significant correlations with TSH in the other two groups (A,B2). Similarly with serum TSH level, variance and mean R-R interval showed negative and mean HRshowed positive correlation in group B1. In group A, all these parameters were positively correlatedwhereas in group B2, RR interval and variance were positively and mean HR was negatively correlated.All these correlations were statistically non significant. With serum FT4 levels, mean R-R and HF n.u.were negatively and mean heart rate, LFnu, LF/HF were positively correlated in all three groups butvariance showed positive in group A and negative correlation in B1 and B2. All these correlations werestatistically non significant. Conclusion: From this study it can be concluded that changes in autonomicnervous regulation are related to altered serum level of TSH and FT4 in hyperthyroids.Key words: HRV; LF; HF; RR interval; HyperthyroidDOI: 10.3329/jbsp.v5i1.5414J Bangladesh Soc Physiol. 2010 June; 5(1): 20-26

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Heart Rate Variability Analysis in Episodic Migraine: A Cross-Sectional Study

Frontiers in Neurology ◽

10.3389/fneur.2021.647092 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lvming Zhang ◽

Shi Qiu ◽

Chunxia Zhao ◽

Peifu Wang ◽

Shengyuan Yu

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Frequency Domain ◽

Time Domain ◽

Domain Analysis ◽

Episodic Migraine ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Autonomic Nervous

Objective: It has been reported that autonomic nervous dysfunction is more prevalent in migraineurs. Heart rate variability (HRV) is a commonly used method to evaluate the cardiac autonomic nervous function modulation. However, HRV changes in migraine are still contradictory. The main objective of this study was to explore the potential HRV change patterns in episodic migraine (EM) and whether there were differences in HRV between EM ictal period and the interictal period.Patients and Methods: We conducted a cross-sectional study including 18 patients with EM and 18 age- and sex-matched controls. The characteristics of demographics, some lifestyle factors, and psychological conditions were assessed at baseline. HRVs including time-domain analysis and frequency-domain analysis were performed in all participants. HRV analyses in migraine were recorded not only in the interictal period but also in the ictal period.Results: All the HRV parameters showed a decreased trend in migraine than controls. Time-domain parameters standard deviation of all NN intervals in 24 h (SDNN) and triangular index were significantly lower in the migraine ictal period than controls separately (SDNN, 56.94 ± 22.09 ± 7.76 vs. 135.78 ± 35.16, p < 0.001; triangular index, 12.61 ± 3.20 vs. 22.11 ± 6.90, p < 0.001). Frequency-domain parameter low-frequency power was also lower in the migraine ictal period than controls (351.28 ± 206.71 vs. 559.61 ± 281.24, p = 0.02). SDNN was much lower in the migraine ictal period than migraine interictal period (56.94 ± 22.09 vs. 115.94 ± 46.88, p < 0.001). HRV changes during migraine interictal period did not differ from the control group. The correlation analysis revealed a negative correlation between visual analog scale and HRV parameters in the migraine ictal period (p = 0.04).Conclusions: The present cross-sectional study indicates that HRV was significantly decreased in EM population especially during the migraine ictal period, which means unbalance of autonomic system in EM. Perhaps larger prospective cohort studies are wanted to validate these findings.

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Mean Heart Rate and Parameters of Heart Rate Variability in Depressive Children and the Effects of Antidepressant Medication

Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie ◽

10.1024/1422-4917/a000672 ◽

2019 ◽

Vol 47 (3) ◽

pp. 253-260 ◽

Cited By ~ 3

Author(s):

Timo D. Vloet ◽

Thomas Jans ◽

Anna Frey ◽

Marie Häußler ◽

Andrea Vloet ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Depressive Disorders ◽

Antidepressant Medication ◽

Cross Sectional Study ◽

Cross Sectional ◽

Healthy Control ◽

Autonomic Cardiac Regulation ◽

The Impact ◽

Mean Heart Rate

Abstract. Introduction: Researchers have repeatedly discovered an association between depression and autonomic cardiac dysregulation in adults. However, corresponding data concerning minors are still rare. Method: For this exploratory, cross-sectional study, we included N = 43 minors (age range 9–17 years). The subjects were depressive subjects with or without antidepressant medication (N = 23) or healthy control children (HC) (N = 20). We assessed several indices of cardiac functioning using long-term electrocardiogram data (mean heart rate, HR, and several parameters of heart rate variability, HRV). We hypothesized that increased HR and reduced HRV are associated with depressive disorders. Furthermore, we assessed the impact of age, sex, and antidepressant medication on HR and HRV. Results: When sex and age were controlled for, HR was significantly increased in depressive minors compared to HC. However, our preliminary data suggest that this might not be the case in medicated patients, and there were no differences between groups regarding HRV parameters. There was no significant correlation in the whole sample between severity of depression and both HR and HRV. In the subsample of patients with depression, antidepressant medication was associated with lower HR and higher indices of HRV. Conclusion: The data indicate an association between depression and altered autonomic cardiac regulation, which can already manifests in minors.

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