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Heart rate variability in hypothyroid patients: A systematic review and meta-analysis. PLoS One 2022; 17:e0269277. [PMID: 35657799 PMCID: PMC9165841 DOI: 10.1371/journal.pone.0269277] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 05/17/2022] [Indexed: 11/19/2022] Open
Abstract
Introduction
Hypothyroidism may be associated with changes in the autonomic regulation of the cardiovascular system, which may have clinical implications.
Objective
To conduct a systematic review and meta-analysis on the impact of hypothyroidism on HRV.
Materials and methods
PubMed, Cochrane, Embase and Google Scholar were searched until 20 August 2021 for articles reporting HRV parameters in untreated hypothyroidism and healthy controls. Random-effects meta-analysis were stratified by degree of hypothyroidism for each HRV parameters: RR intervals (or normal to normal-NN intervals), SDNN (standard deviation of RR intervals), RMSSD (square root of the mean difference of successive RR intervals), pNN50 (percentage of RR intervals with >50ms variation), total power (TP), LFnu (low-frequency normalized unit), HFnu (high-frequency), VLF (very low frequency), and LF/HF ratio.
Results
We included 17 studies with 11438 patients: 1163 hypothyroid patients and 10275 healthy controls. There was a decrease in SDNN (effect size = -1.27, 95% CI -1.72 to -0.83), RMSSD (-1.66, -2.32 to -1.00), pNN50 (-1.41, -1.98 to -0.84), TP (-1.55, -2.1 to -1.00), HFnu (-1.21, -1.78 to -0.63) with an increase in LFnu (1.14, 0.63 to 1.66) and LF/HF ratio (1.26, 0.71 to 1.81) (p <0.001). HRV alteration increased with severity of hypothyroidism.
Conclusions
Hypothyroidism is associated with a decreased HRV, that may be explained by molecular mechanisms involving catecholamines and by the effect of TSH on HRV. The increased sympathetic and decreased parasympathetic activity may have clinical implications.
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Liu C, Lv H, Li Q, Fu S, Tan J, Wang C, Wang X, Ma Y. Effect of thyrotropin suppressive therapy on heart rate variability and QT dispersion in patients with differentiated thyroid cancer. Medicine (Baltimore) 2020; 99:e21190. [PMID: 32664162 PMCID: PMC7360250 DOI: 10.1097/md.0000000000021190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/29/2020] [Accepted: 06/07/2020] [Indexed: 11/26/2022] Open
Abstract
The effects of thyrotropin (TSH) suppressive therapy on autonomic regulation and ventricular repolarization in patients with differentiated thyroid cancer (DTC) have not been elucidated. The aim of present study was to evaluate variation in heart rate variability (HRV) and QT dispersion after TSH suppressive therapy in patients with DTC.Cases, defined as 271 patients with DTC within 1 year of exogenous levothyroxine, and all patients underwent a full history, physical examination, including standard 12 lead electrocardiogram (ECG), and 24 h ambulatory ECG monitoring (Holter) with normal free thyroxine (FT4) and free triiodothyronine (FT3) with levothyroxine. To evaluate effects of TSH suppressive therapy on HRV and QT dispersion, patients were divided into three groups according to different levels of TSH: TSH < 0.1 mIU/L group and 0.1 ≤ TSH < 0.5 mIU/L group were as TSH suppression groups, and 0.5 ≤ TSH < 2.0 mIU/L group was as TSH replacement group.Comparing with 0.5 ≤ TSH < 2.0 mIU/L group, significant changes in both time and frequency domain of HRV and QT dispersion were observed in TSH < 0.1 mIU/L group (P < .001: SDNN, SDANN, HF, LF/HF, QTd, and QTcd; P < .05: rMSSD) and 0.1 ≤ TSH < 0.5 mIU/L group (P < .001: SDNN, HF, LF/HF, QTd, and QTcd), and especially were more pronounced in TSH < 0.1 mIU/L group. Moreover, we found that TSH level was proportional to SDNN (β = 15.829, P < .001), but inversely proportional to LF/HF (β = -0.671, P < .001), QTd (β = -16.674, P < .001) and QTcd (β = -18.314, P < .001) in DTC patients with exogenous levothyroxine.Compared with euthyroid state, patients with suppressed serum TSH have increased sympathetic activity in the presence of diminished vagal tone, ultimately showed sympathovagal imbalance and with an increased inhomogeneity of ventricular recovery times. These findings revealed that TSH suppression therapy had a significant impact on cardiovascular system and had certain guiding role in the treatment and management of patients with DTC.
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Hoshi RA, Andreão RV, Santos IS, Dantas EM, Mill JG, Lotufo PA, Bensenor IM. Linear and nonlinear analyses of heart rate variability following orthostatism in subclinical hypothyroidism. Medicine (Baltimore) 2019; 98:e14140. [PMID: 30681577 PMCID: PMC6358401 DOI: 10.1097/md.0000000000014140] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Subclinical hypothyroidism (SCHypo) is associated with autonomic disturbances that can interfere in physiological responses. This study was designed to evaluate linear and nonlinear variables of heart rate variability (HRV) following postural change, comparing subjects with SCHypo to euthyroid subjects.HRV analyses were performed in 5-minute time series collected in the supine and standing positions from a subsample of 855 participants of the ELSA-Brasil study. The cardiac autonomic nervous function was evaluated by linear time and frequency domain analyses (SDNN, RMSSD, LFms, HFms, and LF/HF ratio) as well as by nonlinear symbolic dynamics (0, 1, and 2 V).After exclusions, 509 (92.0%) euthyroid and 44 (8.0%) SCHypo participants were eligible for analyses. At the baseline supine rest measurement, the 0 V symbolic pattern was higher (27.7 vs 25.4, P = .02) and 2 V was lower (18.0 vs 22.9, P = .02) than in the euthyroid group. Comparing the variation between positions, the 0 V pattern showed a lower delta in SCHypo than in Euthyroid subjects (8.0 vs 10.8%, P = .04).SCHypo presented lower sympathetic and parasympathetic tonus at rest and a blunted sympathetic response to active postural change, marked by reduced variation in the 0 V of symbolic analysis (SA). Additionally, it is suggested that SA of HR dynamics is an alternative and, possibly, a more sensitive method for cardiac autonomic assessment following orthostatism in this population.
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Affiliation(s)
- Rosangela A. Hoshi
- Center for Clinical and Epidemiologic Study for Research, University Hospital, Sao Paulo, SP
| | - Rodrigo V. Andreão
- Department of Electrical Engineering, Federal Institute of Espirito Santo, Vitoria, ES
| | - Itamar S. Santos
- Center for Clinical and Epidemiologic Study for Research, University Hospital, Sao Paulo, SP
| | - Eduardo M. Dantas
- Collegiate of Biological Sciences, Federal University of Vale do Sao Francisco, Petrolina–PE, Brazil
| | - José Geraldo Mill
- Department of Physiological Sciences, Federal University of Espirito Santo, Center of Health Sciences, Vitoria, ES, Brazil
| | - Paulo A. Lotufo
- Center for Clinical and Epidemiologic Study for Research, University Hospital, Sao Paulo, SP
| | - Isabela M. Bensenor
- Center for Clinical and Epidemiologic Study for Research, University Hospital, Sao Paulo, SP
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Gupta S, Goyal P, Idrees S, Aggarwal S, Bajaj D, Mattana J. Association of Endocrine Conditions With Takotsubo Cardiomyopathy: A Comprehensive Review. J Am Heart Assoc 2018; 7:e009003. [PMID: 30371307 PMCID: PMC6404898 DOI: 10.1161/jaha.118.009003] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sonali Gupta
- Department of MedicineSt. Vincent's Medical CenterBridgeportCT
- The Frank H. Netter MD School of Medicine at Quinnipiac UniversityNorth HavenCT
| | - Pradeep Goyal
- The Frank H. Netter MD School of Medicine at Quinnipiac UniversityNorth HavenCT
- Department of RadiologySt. Vincent's Medical CenterBridgeportCT
| | - Sana Idrees
- Department of MedicineSt. Vincent's Medical CenterBridgeportCT
- The Frank H. Netter MD School of Medicine at Quinnipiac UniversityNorth HavenCT
| | - Sourabh Aggarwal
- Cardiology DivisionDepartment of MedicineUniversity of Nebraska Medical CenterOmahaNE
| | - Divyansh Bajaj
- Department of MedicineSt. Vincent's Medical CenterBridgeportCT
- The Frank H. Netter MD School of Medicine at Quinnipiac UniversityNorth HavenCT
| | - Joseph Mattana
- Department of MedicineSt. Vincent's Medical CenterBridgeportCT
- The Frank H. Netter MD School of Medicine at Quinnipiac UniversityNorth HavenCT
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Kalra P, Yeragani VK, Prasanna Kumar KM. Cardiac autonomic function and vascular profile in subclinical hypothyroidism: Increased beat-to-beat QT variability. Indian J Endocrinol Metab 2016; 20:605-611. [PMID: 27730068 PMCID: PMC5040038 DOI: 10.4103/2230-8210.190527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Patients with subclinical hypothyroidism (SH) may have higher incidence of coronary heart disease and autonomic dysfunction. DESIGN OF THE STUDY Prospective case control study. AIM AND OBJECTIVES To evaluate beat-to-beat QT variability and vascular stiffness in patients with SH compared to normal controls. MATERIALS AND METHODS We compared linear and nonlinear measures of cardiac repolarization liability using beat-to-beat QT intervals derived from the surface electrocardiogram during supine posture and vascular indices including pulse wave velocity and ankle-brachial index (ABI) during supine posture between female patients with SH and age- and sex-matched normal controls. Spectral analysis was done at very low frequency (LF) (0.003-0.04 Hz), Low frequency (LF) (0.04-0.15 Hz), and high frequency (HF) (0.15-0.4 Hz). The HF represents vagal regulation (parasympathetic) and LF represents both parasympathetic and sympathetic regulation. RESULTS We recruited 58 women with a mean age of 31.83 ± 8.9 years and 49 controls with mean age of 32.4 ± 9.9 years (P = NS). QT variability index (QTvi) was higher in cases compared to controls (P = 0.01). The ratio of LF/HF of R-R interval which is an index of sympathovagal tone was significantly more in cases compared to controls (P = 0.02). The difference in the left minus the right ABI was significant between cases and controls (P = 0.03). CONCLUSIONS The cases had lower parasympathetic activity as compared to controls, and there was a predominance of sympathetic activity in cases. QTvi may be an important noninvasive tool in this group of patients to study the risk of cardiovascular mortality.
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Affiliation(s)
- Pramila Kalra
- Department of Endocrinology, M.S. Ramaiah Medical College, Bengaluru, Karnataka, India
| | - Vikram K. Yeragani
- Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada
| | - K. M. Prasanna Kumar
- Centre for Diabetes and Endocrine Care, Bangalore Diabetes Hospital, Bengaluru, Karnataka, India
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Guan F, Zhao H, Jiao B, Liu S, Sa R, Hou S, Lin Q, Wang Q, Lin C. Discriminant function analysis of the occurrence risk of abnormal electrocardiogram in thyroidectomized differentiated thyroid carcinoma patients with short-term overt hypothyroidism. Ann Nucl Med 2015; 30:138-44. [PMID: 26692011 DOI: 10.1007/s12149-015-1046-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 11/14/2015] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The common form and risk factors of electrocardiogram (ECG) abnormality in thyroidectomized differentiated thyroid carcinoma (DTC) patients with short-term overt hypothyroidism were investigated and some discriminant formulas for forecasting the occurrence of abnormal ECG in this specific population were deduced in this study. METHODS A total of 260 thyroidectomized DTC patients were retrospectively reviewed, 67 of whom had abnormal ECG and 193 normal ECG after short-term (3 weeks) levothyroxine (L-T4) withdrawal. One-way ANOVA, Spearman's rank correlation analysis and discriminant function analysis were performed using data from these DTC patients. RESULTS A flat or inverted T wave in inferior myocardial and left ventricular wall leads was the most common abnormal ECG finding in short-term overt hypothyroidism. Statistical analyses showed that age, interval, TSH-end (The serum hormothyrin level at the end of L-T4 withdrawal for 3 weeks), and TSH-vel (The average ascending velocity of serum hormothyrin level during L-T4 withdrawal for 3 weeks) were statistically significant and positively correlated with the occurrence of abnormal ECG. Meanwhile, TSH-vel showed the highest correlation coefficient (r = 0.358, p = 0.000). The formulas, especially deduced from age, interval and TSH-vel, could discriminate patients with abnormal ECG or not as high as 77.6 and 70.5%, respectively (resubstitution accuracy: 72.3%). CONCLUSION The thyroidectomized DTC patients undergoing short-term L-T4 withdrawal before their first radioiodine ablative therapy, who had one or more of the above-mentioned risk factors, are likely to show abnormal ECG findings. The formulas from discriminant function analysis may be helpful for predicting patients with abnormal ECG with short-term L-T4 withdrawal and allow appropriate medical intervention beforehand.
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Affiliation(s)
- Feng Guan
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
| | - Hongguang Zhao
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
| | - Benzheng Jiao
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
| | - Shanshan Liu
- Department of Hematology and Oncology, First Hospital of Jilin University, Changchun, China.
| | - Ri Sa
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
| | - Sen Hou
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
| | - Qiuyu Lin
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
| | - Qi Wang
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
| | - Chenghe Lin
- Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
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Madias JE. Is hypothyroidism (on levothyroxine replacement) a precipitant of Takotsubo syndrome? Int J Cardiol 2015; 187:29-30. [PMID: 25828305 DOI: 10.1016/j.ijcard.2015.03.355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Accepted: 03/24/2015] [Indexed: 11/26/2022]
Affiliation(s)
- John E Madias
- Icahn School of Medicine at Mount Sinai, New York, NY, United States; Division of Cardiology, Elmhurst Hospital Center, Elmhurst, NY, United States.
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Wijngaarden MA, Pijl H, van Dijk KW, Klaassen ES, Burggraaf J. Obesity is associated with an altered autonomic nervous system response to nutrient restriction. Clin Endocrinol (Oxf) 2013; 79:648-51. [PMID: 23252937 DOI: 10.1111/cen.12100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 11/02/2012] [Accepted: 11/07/2012] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Heart rate variability (HRV) reflects the balance of activities of sympathetic and parasympathetic components of the autonomic nervous system. We compared HRV parameters in response to a prolonged fast in obese versus normal weight humans. In addition, the effect of weight-loss was evaluated in obese individuals. DESIGN Intervention study. PATIENTS The study subjects included 14 nondiabetic obese (12 females/2 males, aged 30 ± 3 years, Body Mass Index (BMI) 35·2 ± 1·2 kg/m(2) ) and 12 lean subjects (10 females/2 males, aged 27 ± 3 years, BMI 23·3 ± 0·5 kg/m(2) ). MEASUREMENTS HRV was examined 75 min after standardized breakfast and after a 48-h fast in 14 nondiabetic obese and 12 lean subjects. The postprandial measurement was repeated in 12 obese subjects after weight-loss. RESULTS In lean subjects, fasting decreased high-frequency (HF) power by 43% (P < 0·05) and decreased low-frequency (LF) power by 37% (P = 0·1), leaving the LF/HF ratio unchanged (P = 0·7). In the obese group, autonomic nervous system tone shifted to sympathetic dominance as the LF/HF increased from 0·61 to 1·14 (P = 0·03). After an average weight-loss of 13·8 kg in obese subjects, a trend for sympathetic dominance was found; the LF/HF ratio increased by 56% (P = 0·06). CONCLUSION Our data show that a 48-h fast leaves autonomic nervous system balance unaltered in lean subjects. In contrast, a 48-h fast, as well as weight-loss, induces sympathetic dominance in obese humans.
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Affiliation(s)
- M A Wijngaarden
- Department of Endocrinology & Metabolism, Leiden University Medical Center, Leiden, The Netherlands
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Mahajan AS, Lal R, Dhanwal DK, Jain AK, Chowdhury V. Evaluation of autonomic functions in subclinical hypothyroid and hypothyroid patients. Indian J Endocrinol Metab 2013; 17:460-4. [PMID: 23869303 PMCID: PMC3712377 DOI: 10.4103/2230-8210.111642] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Autonomic dysfunction may contribute to cardiovascular morbidity in subclinical hypothyroid patients. It is controversial whether the abnormality exists in sympathetic or the parasympathetic function. It is also not known whether the severity of autonomic dysfunction is related to the degree of thyroid deficiency. DESIGN OF STUDY Prospective case control. MATERIALS AND METHODS Autonomic functions based on heart rate (HR) and blood pressure (BP) responses to various maneuvers were evaluated and scored in twenty two subclinical hypothyroid patients, 30-50 years and compared with twenty hypothyroid patients. Biochemical estimation of TSH, fT3, fT4, TPO antibody was done. RESULT Sympathetic function abnormalities were seen in 82% subclinical hypothyroid patients and 85%hypothyroid patients when one test was abnormal. Parasympathetic dysfunction was also recorded in eight patients in both groups. When two abnormal tests were used as the selection criteria sympathetic function abnormality was observed in about 41% subclinical hypothyroid and 65% hypothyroid patients. There were no intergroup differences in autonomic functions, score and TPO levels. The TSH levels were not related to type or degree of autonomic dysfunction. Systolic BP in both groups and diastolic BP in hypothyroid patients were higher with lower thyroxine levels but the patients were normotensive. CONCLUSION Autonomic dysfunction of comparable degree was seen in subclinical hypothyroid and hypothyroid patients. Sympathetic function abnormality was more common although decreased parasympathetic function reactivity was also present. These abnormalities were unrelated to TSH levels.
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Affiliation(s)
- Aarti S. Mahajan
- Department of Physiology, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi, India
| | - Ram Lal
- Department of Medicine, Government Medical College, Haldwani, Uttarakhand, India
| | - Dinesh K. Dhanwal
- Department of Medicine, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi, India
| | - Ajay K. Jain
- Department of Physiology, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi, India
| | - Veena Chowdhury
- Department of Radiology, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi, India
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Pal GK, Pal P, Nanda N, Amudharaj D, Adithan C. Cardiovascular dysfunctions and sympathovagal imbalance in hypertension and prehypertension: physiological perspectives. Future Cardiol 2013; 9:53-69. [DOI: 10.2217/fca.12.80] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hypertension (HTN) and prehypertension (pre-HTN) have been identified as independent risk factors for adverse cardiovascular events. Recently, increased psychosocial stress and work stress have contributed to the increased prevalence of HTN and pre-HTN, in addition to the contribution of obesity, diabetes, poor food habits and physical inactivity. Irrespective of the etiology, sympathetic overactivity has been recognized as the main pathophysiologic mechanism in the genesis of HTN and pre-HTN. Sympathovagal imbalance owing to sympathetic overactivity and vagal withdrawal is reported to be the basis of many clinical disorders. However, the role played by vagal withdrawal has been under-reported. In this review, we have analyzed the pathophysiologic involvement of sympathovagal imbalance in the development of HTN and pre-HTN, and the link of sympathovagal imbalance to cardiovascular dysfunctions. We have emphasized that adaptation to a healthier lifestyle will help improve sympathovagal homeostasis and prevent the occurrence of HTN and pre-HTN.
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Affiliation(s)
- Gopal Krushna Pal
- Department of Physiology, Jawaharlal Institute of Post-graduate Medical Education & Research (JIPMER), Puducherry – 605 006, India
| | - Pravati Pal
- Department of Physiology, Jawaharlal Institute of Post-graduate Medical Education & Research (JIPMER), Puducherry – 605 006, India
| | - Nivedita Nanda
- Department of Biochemistry, Pondicherry Institute of Medical Sciences (PIMS), Puducherry – 605 014, India
| | - Dharmalingam Amudharaj
- Department of Physiology, Jawaharlal Institute of Post-graduate Medical Education & Research (JIPMER), Puducherry – 605 006, India
| | - Chandrasekaran Adithan
- Department of Pharmacology, Jawaharlal Institute of Post-graduate Medical Education & Research (JIPMER), Puducherry – 605 006, India
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Echeverría J, Solís L, Pérez J, Gaitán-González M, Rivera I, Mandujano M, Sánchez M, González-Camarena R. The autonomic condition of children with congenital hypothyroidism as indicated by the analysis of heart rate variability. Auton Neurosci 2012; 167:7-11. [DOI: 10.1016/j.autneu.2011.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 09/30/2011] [Accepted: 10/24/2011] [Indexed: 10/15/2022]
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Celik A, Aytan P, Dursun H, Koc F, Ozbek K, Sagcan M, Kadi H, Ceyhan K, Onalan O, Onrat E. Heart rate variability and heart rate turbulence in hypothyroidism before and after treatment. Ann Noninvasive Electrocardiol 2012; 16:344-50. [PMID: 22008489 DOI: 10.1111/j.1542-474x.2011.00461.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Cardiac autonomic dysfunction may develop in patients with clinical or subclinical thyroid hormone deficiency. Heart rate variability (HRV) and heart rate turbulence (HRT) are used for evaluating changes in cardiac autonomic functions and also used to provide risk stratification in cardiac and noncardiac diseases. The aim of this study is to evaluate cardiac autonomic functions before and 6 months after thyroid replacement therapy in patients with thyroid hormone deficiency. METHODS Forty hypothyroid patients (mean age 48 ± 13, four male) and 31 healthy controls (mean age 51 ± 12, three male) were included in the study. Twenty-four hour ambulatory electrocardiogram recordings were taken using Pathfinder Software Version V8.255 (Reynolds Medical). The time domain parameters of HRV analysis were performed using the Heart Rate Variability Software (version 4.2.0, Norav Medical Ltd, Israel). HRT parameters, Turbulence Onset (TO), and Turbulence Slope (TS) were calculated with HRT! View Version 0.60-0.1 software. RESULTS HRV and HRT parameters were decreased in the patient group (SDNN; P < 0.001, SDANN; P < 0.009, RMSSD; P = 0.049, TO; P = 0.035, TS; P < 0.001). After 6 months of thyroid replacement therapy, there were no significant changes observed in either HRV or HRT. CONCLUSIONS Hypothyroidism may cause cardiac autonomic dysfunction. Treating hypothyroidism with L-thyroxine therapy does not effectively restore cardiac autonomic function. HRV and HRT can be used as to help monitor cardiovascular-related risk in this population.
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Affiliation(s)
- Atac Celik
- Cardiology Department, Faculty of Medicine, Gaziosmanpasa University, Tokat, Turkey.
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Debeij J, Cannegieter SC, VAN Zaane B, Smit JWA, Corssmit EPM, Rosendaal FR, Romijn JA, Dekkers OM. The effect of changes in thyroxine and thyroid-stimulating hormone levels on the coagulation system. J Thromb Haemost 2010; 8:2823-6. [PMID: 20840332 DOI: 10.1111/j.1538-7836.2010.04054.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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