Decrease In Heart Rate Research Articles

Intra-operative hypertension as a predictor of surgical outcomes in microvascular decompression surgery for trigeminal neuralgia

PurposeThe trigeminocardiac reflex (TCR) has traditionally been characterized by a sudden decrease in heart rate, asystole, or hypotension during the manipulation of the trigeminal nerve (MTN) or its branches. While this classical TCR is well-documented, there is limited literature on alternative forms of TCR, such as the development of intraoperative hypertension (HTN) or tachycardia, and the underlying pathogenesis. Furthermore, a gap exists in understanding the correlation between intraoperative blood pressure readings and postoperative outcomes, particularly regarding pain relief in patients with trigeminal neuralgia (TN). Our study aims to examine intraoperative blood pressure trends during microvascular decompression (MVD) for TN and assess their impact on postoperative outcomes.MethodsWe selected 90 patients who underwent MVD for TN treatment. Blood pressure and heart rate were recorded both preoperatively and during the procedure, specifically during the MTN period, using an arterial line. The Barrow Neurological Institute (BNI) Pain Scale was calculated for all patients both pre- and post-operatively to evaluate pain relief after surgery.ResultsThe mean age of the patients was 61.0 ± 12.35 years, with 64.4% being females. Classical TCR (hypotension) was observed in only 2.2% of patients, whereas 80% of patients developed hypertension (≥ 140/90) during MTN. The mean preoperative systolic blood pressure was 128 ± 22.25, and the mean intraoperative systolic blood pressure during MTN was 153.1 ± 20.2. An analysis of covariance, utilizing either preoperative BNI or duration of symptoms as covariate variables, revealed a statistically significant association between intraoperative HTN and postoperative BNI. A linear regression model demonstrated that intraoperative HTN following MTN significantly predicted a lower postoperative BNI score (p = 0.006).ConclusionsIntraoperative HTN during MTN, an observed yet underexplored phenomenon, demonstrated a correlation with improved postoperative outcomes. Furthermore, it is recommended to conduct additional investigations into potential neurovascular conflicts in patients not manifesting intraoperative HTN following MTN. A comprehensive understanding of TCR, encompassing its various forms, is vital for optimizing surgical management. This study underscores the imperative for further research to unravel the mechanisms linking intraoperative HTN to surgical outcomes in TN patients.

Investigation of [11C]carfentanil for mu opioid receptor quantification in the rat brain

[11C]Carfentanil ([11C]CFN) is the only selective carbon-11 labeled radiotracer currently available for positron emission tomography (PET) imaging of mu opioid receptors (MORs). Though used extensively in clinical research, [11C]CFN has not been thoroughly characterized as a tool for preclinical PET imaging. As we were occasionally observing severe vital sign instability in rat [11C]CFN studies, we set out to investigate physiological effects of CFN mass and to explore its influence on MOR quantification. In anesthetized rats (n = 15), significant dose-dependent PCO2 increases and heart rate decreases were observed at a conventional tracer dose range (IV, > 100 ng/kg). Next, we conducted baseline and retest [11C]CFN PET scans over a wide range of molar activities. Baseline [11C]CFN PET studies (n = 27) found that nondisplaceable binding potential (BPND) in the thalamus was positively correlated to CFN injected mass, demonstrating increase of MOR availability at higher injected CFN mass. Consistently, when CFN injected mass was constrained < 40 ng/kg (~ 10% MOR occupancy in rats), baseline MOR availability was significantly decreased. For test–retest variability (TRTV), better reproducibility was achieved by controlling CFN injected mass to limit the difference between scans. Taken together, we report significant cardiorespiratory depression and a paradoxical influence on baseline MOR availability at conventional tracer doses in rats. Our findings might reflect changes in cerebral blood flow, changes in receptor affinity, or receptor internalization, and merits further mechanistic investigation. In conclusion, rat [11C]CFN PET requires stringent quality assurance of radiotracer synthesis and mass injected to avoid pharmacological effects and limit potential influences on MOR quantification and reproducibility.

Evaluation of Exposure to Bisphenol Analogs through Canned and Ready-to-Eat Meal Consumption and Their Possible Effects on Blood Pressure and Heart Rate.

Bisphenols are endocrine-disrupting chemicals used in plastics and resins for food packaging. This study aimed to evaluate the exposure to bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) associated with the consumption of fresh, canned, and ready-to-eat meals and determine the effects of bisphenols on blood pressure and heart rate. Forty-eight healthy young adults were recruited for this study, and they were divided into the following three groups: fresh, canned, and ready-to-eat meal groups. Urine samples were collected 2, 4, and 6 h after meal consumption, and blood pressure and heart rate were measured. The consumption of ready-to-eat meals significantly increased urine BPA concentrations compared with canned and fresh meal consumption. No significant difference in BPS and BPF concentrations was observed between the groups. The consumption of ready-to-eat meals was associated with a significant increase in systolic blood pressure and pulse pressure and a marked decrease in diastolic blood pressure and heart rate. No significant differences were noted in blood pressure and heart rate with canned and fresh meal consumption. It can be concluded that total BPA concentration in consumed ready-to-eat meals is high. High BPA intake causes increase in urinary BPA concentrations, which may, in turn, lead to changes in some cardiovascular parameters.

Reproductive toxicity and molecular responses induced by telmisartan in Daphnia magna at environmentally relevant concentrations

With aging population increasing globally, the use of pharmaceutically active compounds is rising. The cardiovascular drug telmisartan has been widely detected in various environmental compartments, including biota, surface waters, and sewage treatment plant effluents at concentrations ranging from ng/L to μg/L levels. This study evaluated the effects of telmisartan on the microcrustacean Daphnia magna at a wide range of concentrations (0.35, 0.70, 1.40, 500, and 1000 μg/L) and revealed significant ecotoxicological implications of this drug, even at environmentally relevant concentration. Acute exposure to telmisartan (1.40, 500, and 1000 μg/L) resulted in a notable decrease in heart rate, while chronic exposure accelerated the time to the first brood by 3 days and reduced neonate body size. Molecular investigations revealed marked downregulation of vitellogenin genes (Vtg1 and Vtg2). Non-monotonic dose responses were observed for gene expression, early-stage body length, and the total number of offspring produced, while the heart rate and time to the first brood showed clear concentration-dependent responses. These findings highlight the potential risks, notably to reproductive capacity, associated with exposure to telmisartan in environmentally relevant concentration, suggesting the need for further studies on the potential long-term ecological consequences.

Unraveling the temporal interplay of slow-paced breathing and prefrontal transcranial direct current stimulation on cardiac indices of autonomic activity.

The neurovisceral integration model proposes that information flows bidirectionally between the brain and the heart via the vagus nerve, indexed by vagally mediated heart rate variability (vmHRV). Voluntary reduction in breathing rate (slow-paced breathing, SPB, 5.5 Breathing Per Minute (BPM)) can enhance vmHRV. Additionally, prefrontal transcranial direct current stimulation (tDCS) can modulate the excitability of the prefrontal region and influence the vagus nerve. However, research on the combination of SPB and prefrontal tDCS to increase vmHRV and other cardiac (heart rate (HR) and blood pressure) and peripheral (skin conductance) indices is scarce. We hypothesized that the combination of 20 min of SPB and prefrontal tDCS would have a greater effect than each intervention in isolation. Hence, 200 participants were divided into four groups: active tDCS with SPB, active tDCS with 15 BPM breathing, sham tDCS with SPB, and sham tDCS with 15 BPM breathing. Regardless of the tDCS condition, the 5.5 BPM group showed a significant increase in vmHRV over 20 minutes and significant decreases in HR at the first and second 5-min epochs of the intervention. Regardless of breathing condition, the active tDCS group exhibited higher HR at the fourth 5-min epoch of the intervention than the sham tDCS group. No other effects were observed. Overall, SPB is a robust technique for increasing vmHRV, whereas prefrontal tDCS may produce effects that counteract those of SPB. More research is necessary to test whether and how SPB and neuromodulation approaches can be combined to improve cardiac vagal tone.

Social support moderates association between area deprivation index and changes in physical health among adults in the Baltimore Study of Black Aging (BSBA)

ABSTRACT Despite the association of neighborhood quality with poorer adult health, limited research has explored the association between neighborhood disadvantage, e.g. Area Deprivation Index (ADI), and older Black adults’ health, prospectively. This observational study examined the association between ADI and changes in longitudinal physical health within older Black adults. The analytic sample (n = 317) included data from waves 1 & 2 of the Baltimore Study of Black Aging: Patterns of Cognitive Aging (BSBA-PCA). Study variables included the Area Deprivation Index (ADI), objective (e.g. average heart rate) and subjective (e.g. activities of daily living) measures of physical health. Multiple linear regression models were conducted controlling for sociodemographic and social support characteristics. Participants living in more disadvantaged neighborhoods, based on national and state ADIs, were more likely to have a decreasing heart rate even after adjusting for covariates. Likewise, participants reporting increasing levels of ADL difficulty were living in a neighborhood with greater disadvantage based on national and state ADI rankings. Significant social support received and ADI (national and state) interactions were observed for average heart rate. The findings suggest that research on the effect of neighborhood quality and social support can enhance our understanding of its impact on older Black adults’ health prospectively.

Comparison of General Anesthesia and Spinal Anesthesia on Hemodynamic Stability in Patients Undergoing Hernia Repair

Introduction. The issue of choosing the optimal anesthesia that is least dangerous to the patient’s life is still the main concern of the workers in the anesthesia and intensive care department, including techniques, medications, plans, and instructions followed in order to choose the best anesthesia. It can also be said that spinal anesthesia is the best and most standard anesthesia for those who repair hernia.The aim of the study — learn about obtaining and verifying hemodynamic stability in patients undergoing hernia repair under anesthesia.Materials and methods. An accurate and recent study of patients attending Al-Hussein Medical City and Al-Hassan Hospital in the city of Karbala. We included 100 patients who underwent a herniotomy, were divided into two groups on the types of general and spinal anesthesia. Fifty patients received general anesthesia and 50 patients received spinal anesthesia. Data related to the patient’s age, weight, change in blood pressure and pulse rate were analyzed. The study analyzed patients aged 20–90, dividing them into two groups: general anesthesia (GA) and spinal anesthesia (SA), for careful follow-up before, during, and after operations.Results. We show that it is also more stable in SA which is about 56 % in comparison to GA which is about 40 % but increased blood pressure is more in GA which was 32 % and 24 % in SA, but decreased blood pressure is also more in GA which was 28 % and in SA was 20 %. In this study, as shown, there is more stability in heart rate, which is 56 % in SA but in GA it is 32 % and the increase in heart rate was 34 % in SA but was 60 % in GA. The decreased heart rate was 10 % in SA and about 8 % in GA and the effect of SA is more stable.Conclusions. We found spinal anesthesia was more than general anesthesia in stability of blood pressure and heart rate and minimum or normal.

Moderately intense physical exercise alleviates electrocardiographic changes induced by cisplatin in rats

Introduction and objectiveCisplatin induces many collateral effects such as gastrointestinal disorders, nephrotoxicity, and dysautonomia. Recently our group showed that cisplatin treatment induces gastric emptying delay and that physical exercise and treatment with pyridostigmine prevent this change. In the current study, we investigated the role of moderate exercise on cardiac activity and autonomic balance in rats treated with cisplatin. MethodsMale Wistar rats were divided into saline, cisplatin, exercise, and exercise+cisplatin groups. Cardiac and autonomic disorders were induced by (cisplatin – 3 mg/kg, i.p. once a week/per 5 weeks). Exercise consists of swimming (1 hour per day/5× day per week/per 5 weeks without overload). Forty-eight hours after the last session of the training or treatment, we assessed the cardiac activity and HRV via electrocardiogram analysis in DII derivation. ResultsCisplatin increase (p<0.05) R–R′ interval and decrease (p<0.05) heart rate vs. saline. Exercise+cisplatin prevented (p<0.05) changes in R–R′ interval. Exercise per se induced bradycardia vs. saline group. We observed an increase in LF (nu) and a decrease in HF (nu) in the cisplatin group vs. saline. These changes were not significant. Moreover, cisplatin treatment increased (p<0.05) QT, QTc, and JT intervals compared with the saline group. In the exercise+cisplatin groups these increases were prevented significantly (p<0.05). ConclusionIn the current study, chronic use of cisplatin induced electrocardiographic changes without altering autonomic balance. Moderate physical exercise prevented this phenomenon indicating that exercise can be beneficial in patients in chemotherapy.

Immunotoxicity of legacy and alternative per- and polyfluoroalkyl substances on zebrafish larvae

Hexafluoropropylene oxide dimer acid (HFPO-DA) and perfluoroethylcyclohexane sulfonate (PFECHS) are increasingly used as alternatives for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). However, their immunotoxicity and underlying molecular mechanisms remain poorly understood. Here, to assess immunotoxic effects, zebrafish embryos were exposed to environmentally relevant concentrations of PFOA, PFOS, HFPO-DA, and PFECHS for four days. Results revealed that all four per- and polyfluoroalkyl substances (PFAS) resulted in decreased heart rate and spontaneous movement, and induced oxidative stress in zebrafish larvae. Notably, HFPO-DA exhibited more severe oxidative stress than PFOA. Immune dysfunction was observed, characterized by elevated cytokine, complement factor, nitric oxide, and neutrophil content, along with a significant decrease in lysozyme content. Transcriptomic analysis revealed the activation of Toll-like receptor (TLR)/NOD-like receptor (NLR)/RIG-I-like receptor (RLR) and associated downstream genes, indicating their pivotal role in PFAS-induced immunomodulation. Molecular docking simulations demonstrated stable interactions between PFAS and key receptors (TLR2, NOD2 and RIG-I). Overall, HFPO-DA and PFECHS exhibited immunotoxic effects in zebrafish larvae similar to legacy PFAS, providing important information for understanding the toxic mode of action of these emerging alternatives.

Effects of baroreflex activation therapy on cardiac function and morphology.

Arterial hypertension (aHTN) plays a fundamental role in the pathogenesis and prognosis of heart failure with preserved ejection fraction (HFpEF). The risk of heart failure increases with therapy-resistant arterial hypertension (trHTN), defined as inadequate blood pressure (BP) control ≥140/90mmHg despite taking ≥3 antihypertensive medications including a diuretic. This study investigates the effects of the BP lowering baroreflex activation therapy (BAT) on cardiac function and morphology in patients with trHTN with and without HFpEF. Sixty-four consecutive patients who had been diagnosed with trHTN and received BAT implantation between 2012 and 2016 were prospectively observed. Office BP, electrocardiographic and echocardiographic data were collected before and after BAT implantation. Mean patients' age was 59.1years, 46.9% were male, and mean body mass index (BMI) was 33.2kg/m2. The prevalence of diabetes mellitus was 38.8%, atrial fibrillation was 12.2%, and chronic kidney disease (CKD) stage ≥3 was 40.8%. Twenty-eight patients had trHTN with HFpEF, and 21 patients had trHTN without HFpEF. Patients with HFpEF were significantly older (64.7 vs. 51.6years, P<0.0001), had a lower BMI (30.0 vs. 37.2kg/m2, P<0.0001), and suffered more often from CKD-stage ≥3 (64 vs. 20%, P=0.0032). After BAT implantation, mean office BP dropped in patients with and without HFpEF (from 169±5/86±4 to 143±4/77±3mmHg [P=0.0019 for systolic BP and 0.0403 for diastolic BP] and from 170±5/95±4 to 149±6/88±5mmHg [P=0.0019 for systolic BP and 0.0763 for diastolic BP]), while a significant reduction of the intake of calcium-antagonists, α2-agonists and direct vasodilators, as well as a decrease in average dosage of ACE-inhibitors and α2-agonists could be seen. Within the study population, a decrease in heart rate from 74 ± 2 to 67 ± 2 min-1 (P=0.0062) and lengthening of QRS-time from 96±3 to 106±4ms (P=0.0027) and QTc-duration from 422±5 to 432±5ms (P=0.0184) were detectable. The PQ duration was virtually unchanged. In patients without HF, no significant changes of echocardiographic parameters could be seen. In patients with HFpEF, posterior wall diameter decreased significantly from 14.0±0.5 to 12.7±0.3mm (P=0.0125), left ventricular mass (LVM) declined from 278.1±15.8 to 243.9±13.4g (P=0.0203), and e' lateral increased from 8.2±0.4 to 9.0±0.4cm/s (P=0.0471). BAT reduced systolic and diastolic BP and was associated with morphological and functional improvement of HFpEF.

Temperature and ST-segment morphology remote monitoring: new perspectives for implantable cardiac monitors in Brugada syndrome.

Patients with Brugada syndrome (BrS) face an increased risk of ventricular arrhythmias and sudden cardiac death. Implantable cardiac monitors (ICMs) have emerged as effective tools for detecting arrhythmias in BrS. Technological advancements, including temperature sensors and improved subcutaneous electrocardiogram (subECG) signal quality, hold promise for further enhancing their utility in this population. We present a case of a 40-year-old man exhibiting a BrS type 2 pattern on 12-lead ECG, who underwent ICM insertion (BIOMONITOR IIIm, BIOTRONIK) due to drug-induced BrS type 1 pattern and a history of syncope, with a negative response to programmed ventricular stimulation. The device contains an integrated temperature sensor and can transmit daily vital data, such as mean heart rate and physical activity. Several months later, remote alerts indicated a temperature increase, along with transmitted subECGs suggesting a fever-induced BrS type 1 pattern. The patient was promptly advised to commence antipyretic therapy. Over the following days, remotely monitored parameters showed decreases in mean temperature, physical activity, and mean heart rate, without further recurrence of abnormal subECGs. ICMs offer valuable insights beyond arrhythmia detection in BrS. Early detection of fever using embedded temperature sensors may improve patient management, while continuous subECG morphological analysis has the potential to enhance risk stratification in BrS patients.

Role of Apigenin in Rats with Type 1 Diabetic Complications

Abstract Background and Aim The main factor contributing to diabetes morbidity and mortality is cardiovascular problems. Apigenin, a naturally occurring flavonoid with anti-inflammatory and anti-diabetic characteristics, was investigated for its cardioprotective potential. Methods Type 1 diabetes model was induced using single injection of streptozotocin and diabetic rats were injected with apigenin. ECG recording and measurement of blood pressure were performed. Biochemical analyses of serum glucose, lipid profile, and creatine kinase were done. Histological examination of cardiac tissues was also performed. Results Diabetic rats had higher levels of glucose and creatine kinase, and impaired lipid profile as compared to the control group. Apigenin improved glycemic control, dyslipidemia, and cardiac function markers. Diabetic group had significantly higher blood pressure values as compared to the control group. The mean systolic and diastolic blood pressure levels dropped after apigenin treatment. ECG showed decrease in heart rate and increase in R-voltage after apigenin-injection as compared to diabetic rats. Moreover, apigenin-injection resulted in reduced histological changes of cardiac tissues compared to diabetic rats. Conclusion Apigenin could serve as potential therapeutic agent to reverse effects of hyperglycemia and its cardiovascular complications in diabetes.

Ameliorating Effects of Intermittent Fasting on Cardiac Dysfunctions in Experimentally Induced thyrotoxicosis in Adult Rats. Role of Ghrelin Hormone

Abstract Background Cardiovascular complications of hyperthyroidism have high morbidity and mortality rates. The cardioprotective effect of intermittent fasting (IF) in addition to the concomitant rise of blood ghrelin hormone level during IF have gained attention, but their effects on thyrotoxic hearts are still unclear. Therefore, we aimed to investigate the impacts of IF on hearts of rats subjected to induced thyrotoxicosis (TH) elucidating the role of ghrelin hormone in the assumed cardio protection. Methods Forty-five adult male Wistar Albino rats in 3 groups: control group, thyrotoxic group, injected IP with L-thyroxine100 μg/kg/day, 5 days/week for 4 weeks and intermittent fasting-treated thyrotoxic group, subjected to alternative day fasting regimen for 4 weeks. cardiac functions were assessed by in-vivo studies (ECG recording and arterial blood pressure evaluation) and in-vitro studies (responses to isoproterenol infusion using Langendorff’s preparation). Results Compared to the TH rats, intermittent fasting showed significant body weight loss, decreased left ventricular and whole heart absolute weights, with significant decrease of heart rate (HR) and prolongation of P-R interval in ECG. The baseline values of PT/LV, HRT and MFR/LV as well as their maximal responses and their delta changes in response to isoproterenol infusion were increased and were positively correlated to ghrelin hormone. Ghrelin hormone was increased in IF rats reaching the control group value and showed positive correlation with GPx and BCL-2. Conclusions IF conferred partial cardioprotective effects against thyrotoxicosis. These effects were attributed – at least partially- to normalization of ghrelin hormone which has anti-inflammatory, antioxidant as well as anti-apoptotic effects.

Association of Dynamic Trajectories of Time-Series Data and Life-Threatening Mass Effect in Large Middle Cerebral Artery Stroke.

Life-threatening, space-occupying mass effect due to cerebral edema and/or hemorrhagic transformation is an early complication of patients with middle cerebral artery stroke. Little is known about longitudinal trajectories of laboratory and vital signs leading up to radiographic and clinical deterioration related to this mass effect. We curated a retrospective data set of 635 patients with large middle cerebral artery stroke totaling 95,463 data points for 10 longitudinal covariates and 40 time-independent covariates. We assessed trajectories of the 10 longitudinal variables during the 72h preceding three outcomes representative of life-threatening mass effect: midline shift ≥ 5mm, pineal gland shift (PGS) > 4mm, and decompressive hemicraniectomy (DHC). We used a "backward-looking" trajectory approach. Patients were aligned based on outcome occurrence time and the trajectory of each variable was assessed before that outcome by accounting for cases and noncases, adjusting for confounders. We evaluated longitudinal trajectories with Cox proportional time-dependent regression. Of 635 patients, 49.0% were female, and the mean age was 69years. Thirty five percent of patients had midline shift ≥ 5mm, 24.3% of patients had PGS > 4mm, and 10.7% of patients underwent DHC. Backward-looking trajectories showed mild increases in white blood cell count (10-11K/UL within 72h), temperature (up to half a degree within 24h), and sodium levels (1-3mEq/L within 24h) before the three outcomes of interest. We also observed a decrease in heart rate (75-65 beats per minute) 24h before DHC. We found a significant association between increased white blood cell count with PGS > 4mm (hazard ratio 1.05, p value 0.007). Longitudinal profiling adjusted for confounders demonstrated that white blood cell count, temperature, and sodium levels appear to increase before radiographic and clinical indicators of space-occupying mass effect. These findings will inform the development of multivariable dynamic risk models to aid prediction of life-threatening, space-occupying mass effect.

Predictive value of early-phase heart rate reduction for subsequent recovery of left ventricular systolic function in heart failure with reduced ejection fraction.

Predictors of heart failure with recovered ejection fraction (HFrecEF) remain to be fully elucidated. This study investigated the impact of heart rate and its change on the recovery of left ventricular ejection fraction (LVEF) in heart failure with reduced ejection fraction (HFrEF). From 398 outpatients who had a history of hospitalisation for heart failure, 138 subjects diagnosed as HFrEF (LVEF < 40%) on heart failure hospitalisation were enrolled and longitudinally surveyed. During follow-up periods more than one year, 64 and 46 patients were identified as HFrecEF (improved LVEF to ≥ 40% and its increase of ≥ 10 points) and persistent HFrEF, respectively. In the overall subjects, the reduction of heart rate through the observation periods was closely correlated with the improvement of LVEF (r = -0.508, p < 0.001). Heart rate on hospital admission for heart failure was markedly higher in patients with HFrecEF (112 ± 26 bpm) than in those with persistent HFrEF (90±18 bpm). Whereas heart rate at the first outpatient visit after discharge was already lower in the HFrecEF group (80 ± 13 vs. 85 ± 13 bpm in the persistent HFrEF group). A multivariate logistic regression analysis revealed that the decrease in heart rate from admission to the first visit after discharge was a significant determinant of HFrecEF (p < 0.001), independently of confounding factors such as ischemic heart disease and baseline LVEF and left ventricular dimension. Our findings suggest that heart rate reduction in the early phase after heart failure onset is a powerful independent predictor of the subsequent recovery of LVEF in HFrEF patients.

The role of routine cardiac investigations before hyperbaric oxygen treatment.

Cardiac complications are a rare but potentially serious consequence of hyperbaric oxygen treatment (HBOT), resulting from increased blood pressure and decreased heart rate and cardiac output associated with treatment. These physiologic changes are generally well-tolerated by patients without preexisting cardiac conditions, although those with known or undetected cardiac disease may be more vulnerable to treatment complications. Currently, there are no universally accepted guidelines for pre-HBOT cardiac screening to identify these patients at heightened risk, leading to variability in practice patterns. In the absence of HBOT-specific evidence, screening protocols might be adapted from the diving medicine community; however, given the important differences in physiological stressors, these may not be entirely applicable to patients undergoing HBOT. Traditional cardiac investigations such as electro- and echo-cardiograms are limited in their ability to detect relevant risk modifying states in the pre-HBOT patient, stymieing their cost-effectiveness as routine tests. In the absence of strong evidence to support routine cardiac investigation, we argue that a comprehensive history and physical exam - tailored to identify high-risk patients based on clinical parameters - may serve as a more practical screening tool. While certain unique patient groups such as those undergoing dialysis or with implanted cardiac devices may warrant specialised assessment, thorough evaluation may be sufficient to identify many patients unlikely to benefit from cardiac investigation in the pre-HBOT setting. A clinical decision-making tool based on suggested low-risk and high-risk features is offered to guide the use of targeted cardiac investigation prior to HBOT.

Oxidative damage and cardiotoxicity induced by 2-aminobenzothiazole in zebrafish (Danio rerio)

There is limited information available on cardiovascular toxicity of 2-Aminobenzothiazole (NTH), a derivative of benzothiazole (BTH) commonly used in tire production, in aquatic organisms. In the present study, the zebrafish embryos were exposed to varying concentrations of NTH (0, 0.05, 0.5, and 5 mg/L) until adulthood and the potential cardiovascular toxicity was assessed. NTH exposure resulted in striking aberrations in cardiac development, including heart looping failure and interference with atrioventricular canal differentiation. RNA-sequencing analysis indicated that NTH causes oxidative damage to the heart via ferroptosis, leading to oxygen supply disruption, cardiac malformation, and ultimately, zebrafish death. Quantitative real-time polymerase chain reaction (qPCR) analysis demonstrated the dysregulation of genes associated with early heart development, contraction, and oxidative stress. Additionally, reactive oxygen species accumulation and glutathione/malondialdehyde levels changes suggested a potential link between cardiac developmental toxicity and oxidative stress. In adult zebrafish, NTH exposure led to ventricular enlargement, decreased heart rate, reduced blood flow, and prolonged RR, QRS, and QTc intervals. To the best of our knowledge, this study is the first to provide evidence of cardiac toxicity and the adverse effects of ontogenetic NTH exposure in zebrafish, revealing the underlying toxic mechanisms connected with oxidative stress damage. These findings may provide crucial insights into the environmental risks associated with NTH and other BTHs.

Application of the electrocardiography method for the diagnosis of foaling in horses

Diagnosis of pregnancy is a responsible and integral procedure in the list of measures aimed at obtaining a healthy horse population. Pregnancy confirmation can be performed using different methods, with ultrasound examination (US) being the most widespread and universal. However, this method has some limitations and disadvantages. An alternative to the ultrasound method for diagnosing pregnancy and monitoring the fetus in the middle and late stages of pregnancy can be the electrocardiography (ECG) method. A description of this method for recording the biopotentials of the fetal heart is found in Soviet and modern foreign literature. However, this method of research is not reflected in modern Russian literature and in practice has been undeservedly forgotten. The purpose of this study is to update data on the described diagnostic method, as well as to assess the possibility and reliability of using the ECG method for diagnosing and monitoring pregnancy in horses.The experiment involved a Hanoverian mare whose pregnancy was confirmed by ultrasound. ECG registration was performed on days 121, 150, 184, 214, 245, 276, 304, 335 of pregnancy.As a result of the research, the following was established. The earliest period of pregnancy at which it was possible to detect a fetal ECG was 150 days. By the 11th month of pregnancy, there was a clear trend towards a decrease in the fetal heart rate and a significant increase in the voltage of the fetal teeth.This type of research is easily reproducible in the field, does not require expensive equipment, is characterized by a high level of objectivity of the data obtained and can be recommended for use in the daily practice of an equine veterinarian. As a research prospect, to identify general patterns and distinguish between states of conditional norm and pathology, it can be recommended to conduct further studies with a larger sample of animals.

Centhaquine Increases Stroke Volume and Cardiac Output in Patients with Hypovolemic Shock.

Introduction: Centhaquine is a resuscitative agent that acts on α2B adrenergic receptors. Its effect on cardiac output in hypovolemic shock patients has not been reported. Methods: This pilot study was conducted in 12 hypovolemic shock patients treated with centhaquine who participated in an open-label phase IV study (NCT05956418). Echocardiography was utilized to measure stroke volume (SV), cardiac output (CO), left ventricular outflow tract velocity time integral (LVOT-VTI) and diameter (LVOTd), heart rate (HR), left ventricular ejection fraction (LVEF) and fractional shortening (LVFS), and inferior vena cava (IVC) diameter before (0 min) and 60, 120, and 300 min after centhaquine (0.01 mg/kg) iv infusion for 60 min. Results: SV was significantly increased after 60, 120, and 300 min. CO increased significantly after 120 and 300 min despite a decrease in HR. IVC diameter and LVOT-VTI at these time points significantly increased, indicating the increased venous return. LVEF and LVFS did not change, while the mean arterial pressure (MAP, mmHg) increased after 120 and 300 min. Positive correlations between IVC diameter and SV (R2 = 0.9556) and between IVC diameter and MAP (R2 = 0.8928) were observed, which indicated the effects of an increase in venous return on SV, CO, and MAP. Conclusions: Centhaquine-mediated increase in venous return is critical in enhancing SV, CO, and MAP in patients with hypovolemic shock; these changes could be pivotal for reducing shock-mediated circulatory failure, promoting tissue perfusion, and improving patient outcomes. Trial Registration: CTRI/2021/01/030263 and NCT05956418.

Enhancing Vagal Tone, Modulating Heart Rate Variability with Auricular Acupressure at Point Zero: A Randomized Controlled Trial.

Point Zero located within the vagus nerve's auricular branch shows promise in addressing imbalances. This study aims to explore its effects on vagal activity using auricular acupressure (AA), measured through heart rate variability (HRV). This single-blinded randomized controlled trial involved 114 healthy volunteers randomly assigned to receive AA (AA group, n = 57) or sham-AA (SA group, n = 57) at Point Zero. The 30-minute procedure comprised six stages: T1 and T2 (pre-intervention), T3 to T5 (intervention), and T6 (post-intervention). Interventions involving 30-s acupoint pressure stimulations at T3 and T5. The HRV-measured outcomes included heart rate (HR), standard deviation of R-R intervals (SDNN), root mean square of successive RR interval differences (RMSSD), natural logarithm of low-frequency power (LnLF), and natural logarithm of high-frequency power (LnHF). In addition, respiratory rate (RR) was monitored for its stability. The AA group demonstrated a significant decrease in HR and increases in SDNN, RMSSD, and LnHF from stages T3 to T6 compared with T1 (baseline), notably prominent at T3 (median changes [25th; 75th percentiles]: -2 [-5; -1], 17.85 [9.65; 31.72], 4.9 [1.08; 10.65], 0.26 [0.00; 0.62], respectively) and T5 (-3 [-6; -1], 19.45 [10.6; 32.89], 6.17 [-0.17; 16.34], 0.40 [-0.14; 0.83], respectively), while the SA group did not. LnLF showed nonsignificant alterations, and RR remained stable in both groups. Despite minor HRV fluctuations, the AA group consistently displayed significantly higher changes in SDNN and RMSSD compared with the SA group from T3 onwards. HR remained unchanged at T6, and LnHF significantly differed only at T5. AA at Point Zero may promptly enhance vagal activity, evident in the modulation of HRV, notably pronounced with pressure stimulation, and can be sustained for at least 5 min. Further studies are needed to assess its long-term effectiveness and efficacy in preventing or treating patients.(Clinical Trial Registration: NCT05586698).