Browsing by Subject "heart rate variability"

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  • Pradhapan, Paruthi; Tarvainen, Mika P.; Nieminen, Tuomo; Lehtinen, Rami; Nikus, Kjell; Lehtimaki, Terho; Kahonen, Mika; Viik, Jari (2014)
  • Ollila, Meri-Maija; Kiviniemi, Antti; Stener-Victorin, Elisabet; Tulppo, Mikko; Puukka, Katri; Tapanainen, Juha; Franks, Stephen; Morin-Papunen, Laure; Piltonen, Terhi (2019)
    OBJECTIVES: Previous studies of women in their 20s and 30s have reported impaired autonomic function in women with polycystic ovary syndrome (PCOS). We aimed to study, for the first time, whether PCOS is associated with impaired cardiac autonomic function independent of metabolic and hormonal status in their late reproductive years. DESIGN: A prospective Northern Finland Birth Cohort 1966 (NFBC1966) study including 5889 women born in 1966 and followed through the age of 46. At that age, n=3706/5123 women (72%) answered the postal questionnaires and n=3280/5123 women (64%) participated in the clinical examination. SETTING: General community. PARTICIPANTS: The sample included women presenting both irregular menses (oligomenorrhoea or amenorrhoea) and hirsutism at age 31 (n=125) or with formally diagnosed PCOS by age 46 (n=181) and women without PCOS symptoms or diagnosis (n=1577). PRIMARY AND SECONDARY OUTCOME MEASURES: Heart rate variability parameters: the root mean square of successive R-R differences (rMSSD), spectral power densities (LF: low frequency and HF: high frequency) and baroreflex sensitivity (BRS). RESULTS: We found that parasympathetic activity (assessed by rMSSD: 19.5 (12.4; 31.9) vs 24.3 (16.1; 34.8) ms, p=0.004 and HF: 172 (75; 399) vs 261 (112; 565) ms(2), p=0.002) and BRS (6.13±3.12 vs 6.99±3.52 ms/mm Hg, p=0.036) were lower in women with PCOS compared with the controls. However, in the multivariate regression analysis, PCOS, body mass index and the free androgen index did not significantly associate with rMSSD, whereas blood pressure, insulin resistance and triglycerides did. CONCLUSIONS: We report here for the first time that late reproductive-aged women with PCOS display impaired cardiac autonomic function manifested as decreased vagal activity. Metabolic status, rather than hyperandrogenaemia and PCOS per se, was the strongest contributing factor. Given the link between cardiac morbidity and impaired autonomic function, the findings underline the importance of screening and treating metabolic abnormalities early on in women with PCOS.
  • Orjatsalo, Maija; Alakuijala, Anniina; Partinen, Markku (2020)
    Introduction:Postural tachycardia syndrome (POTS) is a suspected dysautonomia with symptoms of orthostatic intolerance and abnormally increased heart rate while standing. We aimed to study cardiac autonomic nervous system functioning in head-up tilt (HUT) in adolescents with POTS to find out if parasympathetic tone is attenuated in the upright position. Methods:We compared characteristics of a group of 25 (females 14/25; 56%) adolescents with POTS and 12 (females 4/12; 34%) without POTS aged 9-17 years. We compared heart rate variability with high- and low-frequency oscillations, and their temporal changes in HUT. Results:The high-frequency oscillations, i.e., HF, attenuated in both groups during HUT (p<0.05), but the attenuation was bigger in POTS (p= 0.04). In the beginning of HUT, low-frequency oscillations, i.e., LF, increased more in POTS (p= 0.01), but in the end of HUT, an attenuation in LF was seen in the POTS group (p<0.05), but not in the subjects without POTS. There were no associations of previous infections or vaccinations with POTS. Subjects with POTS were sleepier and their overall quality of life was very low. Conclusion:The results imply to an impaired autonomic regulation while standing in POTS, presenting as a lower HF and higher LF in the beginning of HUT and an attenuated LF in the prolonged standing position.
  • Frondelius, Lilli; Hietaoja, Juha Kalevi; Pastell, Matti; Hänninen, Laura Talvikki; Anttila, Paula; Mononen, Jaakko (2018)
    This Research Communication describes the effect of post-operative pain and non-steroidal anti-inflammatory drug (NSAID) treatment on heart rate variability (HRV) of dairy cows. Postoperative pain in farm animals is often left untreated, and HRV could be a promising tool for assessing pain. The aim of this study was to assess if postoperative state after subcutaneous surgery affects HRV in dairy cows and to determine whether this could be modulated by NSAID. Nine cows were inserted with an implantable electrocardiograph logger. Cows were divided into the NSAID treatment group and the control group. The cows in the NSAID group had higher HRV than the control group, indicating a higher sympathetic activity in control animals, most likely due to untreated post-operative pain. Besides the ethical need for treating pain in production animals, ongoing pain has an adverse effect on animal productivity. Thus post-operative pain alleviation is recommended.
  • Hietaoja, Juha (Helsingfors universitet, 2012)
    The heart rate of an individual varies all the time. This phenomenon is called heart rate variability. Both respiration and physical activity induce variations in heart rate. Heart rate variability can be assessed by studying electrical changes in the heart cycle. Electrical changes can be monitored by measuring ECG (electrocardiography). The main target of this study was to find out cow’s normal heart rate variability while they were awake, ruminating or sleeping. For this study, the heart rate of nine cows was recorded as well as their behavior during that time. Cows were monitored while they were sleeping, ruminating, standing or lying down. Four of the cows were from Finland and five of them from Sweden. From those nine cows, 543 one minute samples were obtained. This was the first time that cow’s heart rate was studied during their sleep cycle. The cows were not stressed in any way and their autonomic nervous system was not affected by drugs. One minute samples were analyzed. Samples were gathered by using a Matlab-based computer program, CowSS. All samples were checked visually, and all errors, for instance missing S-peaks or the errors caused by timing, were corrected. Statistical analysis was made by using a linear mixed effects model. According to the analysis, the best way to represent a cow’s heart rate variability is to use RMSSD-value. RMSSD-value describes the variations of adjacent intervals in different recordings. The result of this study show that during sleep the heart rate and the heart variability of cows are different from humans´. Cows´ sleep periods (NREM- and REM-sleep) are shorter and during REM-sleep the parasympathetic toning is stronger in cows. Cow is herbivore and prey for many predators, which may well explain the dominance of the parasympathetic system. Parasympathetic toning works faster than sympathetic toning, and this may give the cow a better chance to escape.
  • Martikainen, Joni (Helsingfors universitet, 2016)
    Depression is a phenomenon determined by multiple factors and it can be conceptualized both from psychological and physiological point of view. Psychological and physiological risk factors form a vulnerability that predispose to depression. The purpose of this study was to research the relationship between the psychological risk factors of depression and physiological stress reactivity. Cloninger's temperament trait harm-avoidance (Temperament and Character Inventory) and tendency for ruminative thinking (Self-rumination Scale) were used as psychological risk factors in this study. The physiological stress reactivity was measured by the individual differences in the heart rate variability. 58 women were invited to laboratory based on the earlier web-based study (n=588). In laboratory the women answer to self-report questionnaires and their EKG was measured under a stressful task. Study found a statistically significant association between psychological risk factors of depression and physiological stress reactivity. Psychological risk factors of depression constituted a whole that predicted physiological stress reactivity in a specific experimental setting in a statistically significant way. The results of this study can be used as a foundation for the development of more effective medical interventions and psychotherapies, and for the development of more specific categorization of depressive subcategories.
  • Ylikoski, Jukka; Lehtimaki, Jarmo; Pirvola, Ulla; Makitie, Antti; Aarnisalo, Antti; Hyvarinen, Petteri; Ylikoski, Matti (2017)
    Conclusion: Transcutaneous vagal nerve stimulation (tVNS) might offer a targeted, patient-friendly, and low-cost therapeutic tool for tinnitus patients with sympathovagal imbalance. Objectives: Conventionally, VNS has been performed to treat severe epilepsy and depression with an electrode implanted to the cervical trunk of vagus nerve. This study investigated the acute effects of tVNS on autonomic nervous system (ANS) imbalance, which often occurs in patients with tinnitus-triggered stress. Methods: This study retrospectively analysed records of 97 patients who had undergone ANS function testing by heart rate variability (HRV) measurement immediately before and after a 15-60min tVNS stimulation. Results: The pre-treatment HRV recording showed sympathetic preponderance/reduced parasympathetic activity in about three quarters (73%) of patients. Active tVNS significantly increased variability of R-R intervals in 75% of patients and HRV age was decreased in 70% of patients. Either the variability of R-R intervals was increased or the HRV age decreased in 90% of the patients. These results indicate that tVNS can induce a shift in ANS function from sympathetic preponderance towards parasympathetic predominance. tVNS caused no major morbidity, and heart rate monitoring during the tVNS treatment showed no cardiac or circulatory effects (e.g. bradycardia) in any of the patients.