BACKGROUND

Heart rate variability (HRV) is a common tool for assessing autonomic nervous system activity and monitoring training load in athletes. However, limited research has explored how HRV responds to different forms of resistance training, particularly in high-intensity intermittent sports like basketball and football.

This study aims to compare the acute HRV responses between neuromuscular and metabolic training in collegiate athletes involved in high-intensity intermittent sports.

A comparative cross-sectional study with a quasi-experimental crossover design will be employed.

Collegiate athletes will be randomly assigned to undergo both neuromuscular and metabolic training sessions with a one-week wash-out period in between. HRV data will be recorded using the Polar H10 chest strap during each session.

Descriptive statistics will summarize salient participant characteristics and HRV measurements. Inferential analysis will use paired t-tests or Wilcoxon signed-rank tests based on normality, assessed via the Kolmogorov-Smirnov test. All statistical analyses will be conducted using the IBM SPSS (ver.25) with a confidence interval set. at 95% and a critical α equal to 0.05.

Neuromuscular training is expected to elicit higher low-frequency (LF) power and an increased LF/HF ratio, reflecting greater sympathetic activation, while metabolic training is expected to show lower LF power and a decreased LF/HF ratio, indicating a more balanced autonomic response. These findings will offer insights into the differential autonomic impacts of these training modalities.

This study was designed to investigate the cardiovascular effects of sulfur dioxide (SO₂) in the caudal ventrolateral medulla (CVLM) of anesthetized rats and its mechanism. Different doses of SO₂ (2, 20, 200 pmol) or artificial cerebrospinal fluid (aCSF) were injected into the CVLM unilaterally or bilaterally, and the effects of SO₂ on blood pressure and heart rate of rats were observed. In order to explore the possible mechanisms of SO₂ in the CVLM, different signal pathway blockers were injected into the CVLM before the treatment with SO₂ (20 pmol). The results showed that unilateral or bilateral microinjection of SO₂ reduced blood pressure and heart rate in a dose-dependent manner (P < 0.01). Moreover, compared with unilateral injection of SO₂ (2 pmol), bilateral injection of 2 pmol SO₂ produced a greater reduction in blood pressure. Local pre-injection of the glutamate receptor blocker kynurenic acid (Kyn, 5 nmol) or soluble guanylate cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 1 pmol) into the CVLM attenuated the inhibitory effects of SO₂ on both blood pressure and heart rate. However, local pre-injection of nitric oxide synthase (NOS) inhibitor N^G-Nitro-L-arginine methyl ester (L-NAME, 10 nmol) only attenuated the inhibitory effect of SO₂ on heart rate but not blood pressure. In conclusion, SO₂ in rat CVLM has cardiovascular inhibitory effects, and its mechanism is related to the glutamate receptor and NOS/cGMP signal pathways.
Animals ; Rats ; Heart Rate ; Sulfur Dioxide ; Blood Pressure ; Cyclic GMP ; Receptors, Glutamate

OBJECTIVE: To use the low-cost anesthesia monitor for realizing anesthesia depth monitoring, effectively assist anesthesiologists in diagnosis and reduce the cost of anesthesia operation. METHODS: Propose a monitoring method of anesthesia depth based on artificial intelligence. The monitoring method is designed based on convolutional neural network (CNN) and long and short-term memory (LSTM) network. The input data of the model include electrocardiogram (ECG) and pulse wave photoplethysmography (PPG) recorded in the anesthesia monitor, as well as heart rate variability (HRV) calculated from ECG, The output of the model is in three states of anesthesia induction, anesthesia maintenance and anesthesia awakening. RESULTS: The accuracy of anesthesia depth monitoring model under transfer learning is 94.1%, which is better than all comparison methods. CONCLUSIONS The accuracy of this study meets the needs of perioperative anesthesia depth monitoring and the study reduces the operation cost.
Artificial Intelligence ; Neural Networks, Computer ; Heart Rate ; Electrocardiography ; Photoplethysmography/methods* ; Anesthesia

As a new energy source for atrial fibrillation ablation, electric pulse ablation has higher tissue selectivity and biosafety, so it has a great application prospect. At present, there is very limited research on multi-electrode simulated ablation of histological electrical pulse. In this study, a circular multi-electrode ablation model of pulmonary vein will be built on COMSOL5.5 platform for simulation research. The results show that when the voltage amplitude reaches about 900 V, it can make some positions achieve transmural ablation, and the depth of continuous ablation area formed can reach 3 mm when the voltage amplitude reaches 1 200 V. When the distance between catheter electrode and myocardial tissue is increased to 2 mm, a voltage of at least 2 000 V is required to make the depth of continuous ablation area reach 3 mm. Through the simulation of electric pulse ablation with ring electrode, the research results of this project can provide reference for the voltage selection in the clinical application of electric pulse ablation.
Humans ; Heart Rate ; Atrial Fibrillation/surgery* ; Electrodes ; Catheter Ablation ; Electricity

Atrial fibrillation is a common arrhythmia, and its diagnosis is interfered by many factors. In order to achieve applicability in diagnosis and improve the level of automatic analysis of atrial fibrillation to the level of experts, the automatic detection of atrial fibrillation is very important. This study proposes an automatic detection algorithm for atrial fibrillation based on BP neural network (back propagation network) and support vector machine (SVM). The electrocardiogram (ECG) segments in the MIT-BIH atrial fibrillation database are divided into 10, 32, 64, and 128 heartbeats, respectively, and the Lorentz value, Shannon entropy, K-S test value and exponential moving average value are calculated. These four characteristic parameters are used as the input of SVM and BP neural network for classification and testing, and the label given by experts in the MIT-BIH atrial fibrillation database is used as the reference output. Among them, the use of atrial fibrillation in the MIT-BIH database, the first 18 cases of data are used as the training set, and the last 7 cases of data are used as the test set. The results show that the accuracy rate of 92% is obtained in the classification of 10 heartbeats, and the accuracy rate of 98% is obtained in the latter three categories. The sensitivity and specificity are both above 97.7%, which has certain applicability. Further validation and improvement in clinical ECG data will be done in next study.
Humans ; Atrial Fibrillation/diagnosis* ; Support Vector Machine ; Heart Rate ; Algorithms ; Neural Networks, Computer ; Electrocardiography

To comprehensively evaluate the human body's respiratory, circular metabolism and other functions, and to diagnose lung disease, an accurate and reliable pulmonary function test (PFT) is developed. The system is divided into two parts:hardware and software. It realizes the collection of respiratory, pulse oxygen, carbon dioxide, oxygen and other signals, and draws flow-volume curve (FV curve), volume-time curve (VT curve), respiratory waveform, pulse wave, carbon dioxide and oxygen waveform in real time on the upper computer of the PFT system, and conducts signal processing and parameter calculation for each signal. The experimental results prove that the system is safe and reliable, it can accurately measure the basic functions of human body, and provide reliable parameters, and has good application prospects.
Humans ; Carbon Dioxide ; Respiratory Function Tests ; Oxygen ; Heart Rate

OBJECTIVE: To investigate the survival of patients with cardiac arrest and cardiopulmonary resuscitation (CA-CPR), and to analyze the factors influencing survival at 30 days after restoration of spontaneous circulation (ROSC). METHODS: A retrospective cohort study was conducted. Clinical data of 538 patients with CA-CPR admitted to the People's Hospital of Ningxia Hui Autonomous Region from January 2013 to September 2020 were enrolled. The gender, age, underlying disease, cause of CA, type of CA, initial rhythm, presence or absence of endotracheal intubation, defibrillation, use of epinephrine, and 30-day survival rate of patients were collected. The etiology of CA and 30-day survival rate among patients with different ages were compared, as well as the clinical data between patients who survived and died at 30 days after ROSC were also compared. Multivariate Logistic regression was used to analyze the relevant factors affecting the 30-day survival rate of patients. RESULTS: Among 538 patients with CA-CPR, 67 patients with incomplete information were excluded, and 471 patients were enrolled. Among 471 patients, 299 were males and 172 were females. Aged from 0 to 96 years old, 23 patients (4.9%) were < 18 years old, 205 patients (43.5%) were 18 to 64 years old, and 243 patients (51.6%) were ≥ 65 years old. 302 cases (64.1%) achieved ROSC, and 46 patients (9.8%) survived for more than 30 days. The 30-day survival rate of patients aged < 18 years old, 18-64 years old and ≥ 65 years old was 8.7% (2/23), 12.7% (26/205) and 7.4% (18/243), respectively. The main causes of CA in patients younger than 18 years were severe pneumonia (13.1%, 3/23), respiratory failure (13.1%, 3/23), and trauma (13.1%, 3/23). The main causes were acute myocardial infarction (AMI; 24.9%, 51/205), respiratory failure (9.8%, 20/205), and hypoxic brain injury (9.8%, 20/205) in patients aged 18-64 years old, and AMI (24.3%, 59/243) and respiratory failure (13.6%, 33/243) in patients aged ≥ 65 years old. Univariate analysis results revealed that the 30-day survival rate of patients with CA-CPR may be related to the the cause of CA was AMI, initial rhythm was ventricular tachycardia/ventricular fibrillation, endotracheal intubation and epinephrine. Multivariate Logistic regression analysis results showed that CA was caused by AMI [odds ratio (OR) = 0.395, 95% confidence interval (95%CI) was 0.194-0.808, P = 0.011] and endotracheal intubation (OR = 0.423, 95%CI was 0.204-0.877, P = 0.021) was a protective factor for 30 days of survival after ROSC in patients with CA-CPR. CONCLUSIONS The 30-day survival rate of CA-CPR patients was 9.8%. The 30-day survival rate of CA-CPR patients with AMI after ROSC is higher than that of patients with other CA causes, and early endotracheal intubation can improve the prognosis of patients.
Female ; Male ; Humans ; Infant, Newborn ; Infant ; Child, Preschool ; Child ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Aged ; Aged, 80 and over ; Retrospective Studies ; Survival Rate ; Heart Arrest ; Hospitals ; Epinephrine ; Ventricular Fibrillation

INTRODUCTION: MyDiagnostick is an atrial fibrillation (AF) screening tool that has been validated in the Caucasian population in the primary care setting. METHODS: In our study, we compared MyDiagnostick with manual pulse check for AF screening in the community setting. RESULTS: In our cohort of 671 candidates from a multi-ethnic Asian population, AF prevalence was found to be 1.78%. Of 12 candidates, 6 (50.0%) had a previous history of AF and another 6 (50.0%) were newly diagnosed with AF. Candidates found to have AF during the screening were older (72.0 ± 11.7 years vs. 56.0 ± 13.0 years, P < 0.0001) and had a higher CHADSVASC risk score (2.9 ± 1.5 vs. 1.5 ± 1.1, P = 0.0001). MyDiagnostick had a sensitivity of 100.0% and a specificity of 96.2%. In comparison, manual pulse check had a sensitivity of 83.3% and a specificity of 98.9%. CONCLUSION MyDiagnostick is a simple AF screening device that can be reliably used by non-specialist professionals in the community setting. Its sensitivity and specificity are comparable and validated across various studies performed in different population cohorts.
Humans ; Atrial Fibrillation/diagnosis* ; Heart Rate ; Sensitivity and Specificity ; Risk Factors ; Electrocardiography ; Mass Screening

Humans ; Heart Failure/therapy* ; Kidney/physiology* ; Renal Insufficiency ; Glomerular Filtration Rate

OBJECTIVE: To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults. METHODS: This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results. RESULTS: The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m². During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m³, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m³, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m³ increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m³. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter. CONCLUSION Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.
Humans ; Female ; Adult ; Young Adult ; Air Pollutants/analysis* ; Heart Rate/physiology* ; Volatile Organic Compounds/analysis* ; Carbon Dioxide ; Particulate Matter/adverse effects* ; Environmental Pollutants