Long QT syndrome (LQTS) presents a group of inheritable channelopathies with prolonged ventricular repolarization, leading to syncope, ventricular tachycardia, and sudden death. Differentiating LQTS genotypes is crucial for targeted management and treatment, yet conventional genetic testing remains costly and time-consuming. This study aims to improve the distinction between LQTS genotypes, particularly LQT3, through a novel electrocardiogram (ECG)-based approach. Patients with LQT3 are at elevated risk due to arrhythmia triggers associated with rest and sleep. Employing a database of genotyped long QT syndrome E-HOL-03-0480-013 ECG signals, we introduced two innovative parameterization techniques-area under the ECG curve and wave transformation into the unit circle-to classify LQT3 against LQT1 and LQT2 genotypes. Our methodology utilized single-lead ECG data with a 200 Hz sampling frequency. The support vector machine (SVM) model demonstrated the ability to discriminate LQT3 with a recall of 90% and a precision of 81%, achieving an F1-score of 0.85. This parameterization offers a potential substitute for genetic testing and is practical for low frequencies. These single-lead ECG data could enhance smartwatches' functionality and similar cardiovascular monitoring applications. The results underscore the viability of ECG morphology-based genotype classification, promising a significant step towards streamlined diagnosis and improved patient care in LQTS.

• Klíčová slova
• LQT3 discrimination, electrocardiogram classification, electrocardiogram parameterization, long QT syndrome, support vector machine classification,
• MeSH
• dospělí MeSH
• elektrokardiografie * metody   MeSH
• genotyp MeSH
• lidé MeSH
• strojové učení * MeSH
• support vector machine MeSH
• syndrom dlouhého QT * genetika   diagnóza   patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

University students frequently encounter stress and anxiety, impacting their autonomic nervous system and mental health. Rhythmic photic stimulation (RPS) at various frequencies is considered a potential intervention for anxiety and depression, but its effectiveness is not fully understood. This research aimed to assess the impact of RPS at theta (6 Hz), alpha (10 Hz), and beta (25 Hz) frequencies on autonomic nervous system regulation in university students, comparing the effects between those with and without depression symptoms. Conducted at a southern Taiwan university, this quasi-experimental study involved RPS interventions at specified frequencies, with pre and post assessments of heartbeat, blood pressure, and heart rate variability. Among 62 participants (average age 20.29±0.61), those without depression showed a notable blood pressure reduction following theta-frequency RPS compared to other frequencies (p<0.05). A similar pattern was observed when comparing non-depressed and depressed participants after theta-RPS, with depressed individuals experiencing an increase in sympathetic activity (p<0.05). RPS, particularly at theta frequency, can significantly influence the autonomic nervous system, suggesting a potential for reducing anxiety-related physiological markers in university students. Further verification with a larger and longitudinal study is warranted. Key words Binaural beat, Rhythmical photic stimulation, Autonomic nervous system, University student.

• MeSH
• autonomní nervový systém * fyziologie   MeSH
• deprese patofyziologie   psychologie   MeSH
• krevní tlak fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• srdeční frekvence * fyziologie   MeSH
• studenti * psychologie   MeSH
• světelná stimulace * metody   MeSH
• univerzity MeSH
• úzkost patofyziologie   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Marathon training and running have many beneficial effects on human health and physical fitness; however, they also pose risks. To date, no comprehensive review regarding both the benefits and risks of marathon running on different organ systems has been published. MAIN BODY: The aim of this review was to provide a comprehensive review of the benefits and risks of marathon training and racing on different organ systems. A predefined search strategy including keywords (e.g., marathon, cardiovascular system, etc.) and free text search was used. Articles covering running regardless of sex, age, performance level, and event type (e.g., road races, mountain marathons) were considered, whereas articles examining only cycling, triathlon, stress-tests or other sports were excluded. In total, we found 1021 articles in PubMed, Scopus, and Google Scholar, of which 329 studies were included in this review. Overall, marathon training offers several benefits for different organ systems and reduces all-cause mortality. As such, it improves cardiovascular risk factors, leads to favorable cardiac adaptations, enhances lung function, and improves quality of life in chronic kidney disease patients. It also enhances gastrointestinal mobility and reduces the risk of specific tumors such as colorectal cancer and hepatocellular carcinoma. Marathon training enhances bone health and skeletal muscle metabolism. It further positively affects hematopoiesis and cytotoxic abilities of natural killer cells, and may act neuroprotective on a long-term basis. After a marathon, changes in biomarkers suggesting pathological events in certain organ systems such as cardiovascular, renal, gastrointestinal, liver, hematological, immune, musculoskeletal, central nervous, and endocrine systems can often be observed. Mostly, these changes are limited to 1-3 days post-race and usually normalize within a week. Moreover, marathon running poses the risk of serious adverse events such as sudden cardiac death or acute liver failure. Concerning lung function, a decrease after a marathon race was observed. Acute kidney injury, as well as electrolyte imbalances, are relatively common amongst marathon finishers. Many runners complain of gastrointestinal symptoms during or after long-distance running. Many runners suffer from running-related musculoskeletal injuries often impairing performance. A marathon is often accompanied by an acute inflammatory response with transient immunosuppression, making runners susceptible to infections. Also, hormonal alterations such as increased cortisol levels or decreased testosterone levels immediately after a race are observed. Disturbances in sleep patterns are commonly found in marathon runners leading up to or directly after the race. CONCLUSION: All in all, marathon training is generally safe for human health and individual organ systems. Considering the high popularity of marathon running, these findings supply athletes, coaches, sports scientists, and sports medicine practitioners with practical applications. Further large-scale studies examining long-term effects on the cardiovascular, renal, and other system are needed.

• Klíčová slova
• Athletic injury, Endurance training, Exercise overtraining, Sex differences, sports performance,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: The main objective of the present cross-sectional cohort study was to determine whether there is an association between cardiac autonomic regulation, as expressed through heart rate variability (HRV), and cardiorespiratory fitness (CRF), visceral adipose tissue (VAT), and over the long-term living in areas with low or high air pollution. METHODS: The study sample included 1036 (487 females) healthy runners (603) and inactive participants (age 18-65 years) who had lived for at least 5 years in an area with high (Moravian-Silesian; MS) or low (South Bohemian; SB) air pollution in the Czech Republic. A multivariable regression analysis was used to evaluate the associations between multiple independent variables (CRF (peak oxygen consumption), VAT, sex, socioeconomic status (education level), and region (MS region vs. SB region) with dependent variable HRV. The root mean square of successive RR interval differences (rMSSD) was employed for the evaluation of HRV. RESULTS: The multivariable linear regression model revealed that cardiac autonomic regulation (rMSSD) was significantly associated with CRF level (p < .001) and age (p < .001). There were no associations between rMSSD and region (high or low air-pollution), sex, education level or VAT (p > 0.050). CONCLUSIONS: We showed that living in an area with low or high air pollution is not associated with cardiac autonomic modulation in healthy runners and inactive individuals. CRF and age significantly directly and inversely, respectively, associated with HRV. There were no other significant associations.

• MeSH
• autonomní nervový systém fyziologie   MeSH
• dospělí MeSH
• kardiorespirační zdatnost * fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nitrobřišní tuk * MeSH
• průřezové studie MeSH
• senioři MeSH
• srdce fyziologie   MeSH
• srdeční frekvence * fyziologie   MeSH
• znečištění ovzduší * škodlivé účinky   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

BACKGROUND: Autonomic dysfunction is common in dementia, yet its contribution to neurocognitive changes remains unknown. We investigated whether midlife cardiac vagal modulation, indexed by heart rate variability, associates with subsequent cognitive decline in adults without prior coronary heart disease or stroke. METHODS: The sample comprised 2702 (1924 men) individuals initially aged 44-69 years from the UK Whitehall II cohort. Data from the fifth (1997-1999), seventh (2002-2004) and ninth (2007-2009) phases were analysed. Global cognitive function was ascertained from tests assessing memory, reasoning, vocabulary, and fluency. We used 12-lead-ECG-based heart rate variability measures, that primarily reflect vagal modulation (i.e. RMSSD and HF-HRV). Linear mixed-effects models and logistic regression were employed. RESULTS: Results showed consistent associations between both vagally-mediated HRV measures and faster decline in global cognitive function. Specifically, low RMSSD and HF-HRV (lowest versus upper four quintiles) were associated with 0.07 SD (95% CI: -0.13, -0.01) and 0.06 SD (95% CI: -0.12, -0.004) accelerated 10-year cognitive decline after sociodemographic adjustments and faster decline in older ages. Further adjustments for lifestyle factors, medication use and other cardiometabolic conditions did not change the findings. Cognitive decline in individuals with low RMSSD and HF-HRV was estimated to progress 3 and 3.5 years faster per decade, respectively, compared to their counterparts. Additionally, participants with low RMSSD had 37% higher odds of low cognitive function (lowest quintile) at follow-up (OR 1.37: 95% CI,1.03, 1.80). CONCLUSION: Our findings support the aetiological significance of the autonomic nervous system, specifically vagal modulation, in the processes of cognitive decline and neurodegeneration. Low heart rate variability emerges as a potential biomarker indicative of acclerated cognitive decline that may extend over decades.

• Klíčová slova
• Aetiological significance, Autonomic nervous system, Cognitive decline, Heart rate variability, Longitudinal cohort studies,
• Publikační typ
• časopisecké články MeSH

This study aims to explore: (1) the validity of post-exercise ultra-short-term heart rate variability (HRVust) after two different bouts of repeated sprint ability test (RSA), and (2) the relationship between HRVust measure and RSA performance. Twenty adolescent male futsal players voluntarily participated in this study (age: 17.65 ± 1.81 years, body height: 170.88 ± 4.98 cm, body weight: 61.78 ± 4.67 kg). The participants performed a standard RSA test (RSAstandard) and an RSA test with a 10% decrement of the best sprint time test (RSA10%decrement) on two separate occasions within a week. On both occasions, a 5-min resting electrocardiography was administered pre- and post-RSA exercise protocols. The first 30-s (HRVust30s), 60-s (HRVust60s), and 60-120-s (HRVust1-2min) were extracted and used to compare with the standard of 5-min HRV recording (HRVcriterion). The natural logarithm (ln) of the standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive normal-to-normal interval differences (RMSSD) HRV indices were utilised to establish intraclass correlation coefficient (ICC2,1), coefficient of variation (%CV), and Pearson product-moment correlation (r). Results revealed the ICC values of HRVust lnSDNN (RSAstandard = 0.77-0.88; RSA10%decrement = 0.41-0.71) and lnRMSSD (RSAstandard = 0.81-0.86; RSA10%decrement = 0.57-0.82). Furthermore, significantly positive correlations between best sprint time and post-exercise HRVust indices were found in lnSDNN (r = 0.47-0.62; p < 0.05) and lnRMSSD (r = 0.45; p < 0.05). Additionally, a large CV of lnSDNN (RSAstandard = 32%-45%; RSA10%decrement = 29%-39%), lnRMSSD (RSAstandard = 50%-66%; RSA10%decrement = 48%-52%), and ratio (RSAstandard = 45%-126%; RSA10%decrement = 27%-45%) was found after the RSA protocols. In conclusion, the number of bouts of RSA exercise potentially influences the agreement of post-exercise time-domain HRVust indices to standard HRV measure.

• Klíčová slova
• Cardiac-related responses, autonomic nervous system, exercise recovery, parasympathetic activation, time-domain measure,
• MeSH
• běh * fyziologie   MeSH
• cvičení fyziologie   MeSH
• elektrokardiografie MeSH
• lidé MeSH
• mladiství MeSH
• sportovní výkon fyziologie   MeSH
• srdeční frekvence * fyziologie   MeSH
• zátěžový test * metody   MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Reference ranges provide a powerful tool for diagnostic decision-making in clinical medicine and are enormously valuable for understanding normality in pre-clinical scientific research that uses in vivo models. As yet, there are no published reference ranges for electrocardiography (ECG) in the laboratory mouse. The first mouse-specific reference ranges for the assessment of electrical conduction are reported herein generated from an ECG dataset of unprecedented scale. International Mouse Phenotyping Consortium data from over 26,000 conscious or anesthetized C57BL/6N wildtype control mice were stratified by sex and age to develop robust ECG reference ranges. Interesting findings include that heart rate and key elements from the ECG waveform (RR-, PR-, ST-, QT-interval, QT corrected, and QRS complex) demonstrate minimal sexual dimorphism. As expected, anesthesia induces a decrease in heart rate and was shown for both inhalation (isoflurane) and injectable (tribromoethanol) anesthesia. In the absence of pharmacological, environmental, or genetic challenges, we did not observe major age-related ECG changes in C57BL/6N-inbred mice as the differences in the reference ranges of 12-week-old compared to 62-week-old mice were negligible. The generalizability of the C57BL/6N substrain reference ranges was demonstrated by comparison with ECG data from a wide range of non-IMPC studies. The close overlap in data from a wide range of mouse strains suggests that the C57BL/6N-based reference ranges can be used as a robust and comprehensive indicator of normality. We report a unique ECG reference resource of fundamental importance for any experimental study of cardiac function in mice.

• MeSH
• elektrofyziologické techniky kardiologické * MeSH
• elektrokardiografie * MeSH
• inbrední kmeny myší MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH

There are substantial differences in autonomic nervous system activation among heart (cardiac) failure (CF) patients. The effect of acute CF on autonomic function has not been well explored. The aim of our study was to assess the effect of experimental acute CF on heart rate variability (HRV). Twenty-four female pigs with a mean body weight of 45 kg were used. Acute severe CF was induced by global myocardial hypoxia. In each subject, two 5-min electrocardiogram segments were analyzed and compared: before the induction of myocardial hypoxia and >60 min after the development of severe CF. HRV was assessed by time-domain, frequency-domain and nonlinear analytic methods. The induction of acute CF led to a significant decrease in cardiac output, left ventricular ejection fraction and an increase in heart rate. The development of acute CF was associated with a significant reduction in the standard deviation of intervals between normal beats (50.8 [20.5−88.1] ms versus 5.9 [2.4−11.7] ms, p < 0.001). Uniform HRV reduction was also observed in other time-domain and major nonlinear analytic methods. Similarly, frequency-domain HRV parameters were significantly changed. Acute severe CF induced by global myocardial hypoxia is associated with a significant reduction in HRV.

• Klíčová slova
• acute heart failure, experimental model, heart rate variability, pig,
• MeSH
• funkce levé komory srdeční fyziologie   MeSH
• hypoxie MeSH
• ischemická choroba srdeční * MeSH
• prasata MeSH
• srdeční frekvence fyziologie   MeSH
• srdeční selhání * MeSH
• tepový objem MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Vibroacoustic therapy (VAT) uses low-frequency sound, often combined with listening to music, for therapeutic purposes. However, the impact of low-frequency vibration (LFV) on physiological functions and subjective perception is relatively unknown. METHODS: We conducted a randomized cross-over study with the aim of comparing the effect of constant LFV of 40 Hz, its amplitude modulation, and the placebo condition on heart rate variability (HRV), stress perception (measured by visual analogue scales for stress) and mood (measured by UWIST Mood Adjective Check List). RESULTS: Research experiments with various interventions (constant LFV with sound of nature (river in forest), amplitude modulation of the same LFV with sounds of nature and sounds of nature without LFV) were realised involving 24 participants. It was found there was an effect on HRV, stress perception and mood after the interventions. However, there were only seldomly experienced, and mostly nonsignificant, differences between the intervention conditions, so the effects may be attributed to factors other than LFV. CONCLUSIONS: Large scale experimental studies are needed to verify the preliminary findings and to explore various coinciding factors that may have influenced the results of this study, e.g., type of autonomic nervous system. We propose that the effect of LFV exposure may differ when combined with listening to music, and this hypothesis should be investigated in future studies.

• Klíčová slova
• cardiac autonomic regulation, heart rate variability, low frequency vibration, mood, nature sound, stress, subjective perception, vibroacoustic therapy,
• Publikační typ
• časopisecké články MeSH

This paper evaluates variations in solar activity and their impact on the human nervous system, including the manner in which human behavior and decision-making reflect such effects in the context of (symmetrical) social interactions. The relevant research showed that solar activity, manifesting itself through the exposure of the Earth to charged particles from the Sun, affects heart variability. The evaluation methods focused on examining the relationships between selected psychophysiological data and solar activity, which generally causes major alterations in the low-level electromagnetic field. The investigation within this paper revealed that low-level EMF changes are among the factors affecting heart rate variability and, thus, also variations at the spectral level of the rate, in the VLF, (f = 0.01-0.04 Hz), LF (f = 0.04-0.15 Hz), and HF (f = 0.15 až 0.40 Hz) bands. The results of the presented experiments can also be interpreted as an indirect explanation of sudden deaths and heart failures.

• Klíčová slova
• BioGraph Infiniti, ELF, SLF, ULF, heart rate variability, sympathetic and parasympathetic,
• MeSH
• elektrokardiografie * MeSH
• lidé MeSH
• sluneční aktivita MeSH
• srdce MeSH
• srdeční frekvence MeSH
• srdeční selhání * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH