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The application of empirical mode decomposition for the enhancement of cardiotocograph signals

Krupa BN, Mohd Ali MA, Zahedi E

Physiol Meas, 2009 Aug;30(8):729-43.
PMID: 19550027 DOI: 10.1088/0967-3334/30/8/001

Cardiotocograph (CTG) is widely used in everyday clinical practice for fetal surveillance, where it is used to record fetal heart rate (FHR) and uterine activity (UA). These two biosignals can be used for antepartum and intrapartum fetal monitoring and are, in fact, nonlinear and non-stationary. CTG recordings are often corrupted by artifacts such as missing beats in FHR, high-frequency noise in FHR and UA signals. In this paper, an empirical mode decomposition (EMD) method is applied on CTG signals. A recursive algorithm is first utilized to eliminate missing beats. High-frequency noise is reduced using EMD followed by the partial reconstruction (PAR) method, where the noise order is identified by a statistical method. The obtained signal enhancement from the proposed method is validated by comparing the resulting traces with the output obtained by applying classical signal processing methods such as Butterworth low-pass filtering, linear interpolation and a moving average filter on 12 CTG signals. Three obstetricians evaluated all 12 sets of traces and rated the proposed method, on average, 3.8 out of 5 on a scale of 1(lowest) to 5 (highest).

Matched MeSH terms: Heart Rate, Fetal/physiology
Transabdominal fetal heart rate detection using NIR photopleythysmography: instrumentation and clinical results

Gan KB, Zahedi E, Mohd Ali MA

IEEE Trans Biomed Eng, 2009 Aug;56(8):2075-82.
PMID: 19403354 DOI: 10.1109/TBME.2009.2021578

In obstetrics, fetal heart rate (FHR) detection remains the standard for intrapartum assessment of fetal well-being. In this paper, a low-power (< 55 mW) optical technique is proposed for transabdominal FHR detection using near-infrared photoplesthysmography (PPG). A beam of IR-LED (890 nm) propagates through to the maternal abdomen and fetal tissues, resulting in a mixed signal detected by a low-noise detector situated at a distance of 4 cm. Low-noise amplification and 24-bit analog-to-digital converter resolution ensure minimum effect of quantization noise. After synchronous detection, the mixed signal is processed by an adaptive filter to extract the fetal signal, whereas the PPG from the mother's index finger is the reference input. A total of 24 datasets were acquired from six subjects at 37 +/- 2 gestational weeks. Results show a correlation coefficient of 0.96 (p-value < 0.001) between the proposed optical and ultrasound FHR, with a maximum error of 4%. Assessment of the effect of probe position on detection accuracy indicates that the probe should be close to fetal tissues, but not necessarily restricted to head or buttocks.

Matched MeSH terms: Heart Rate, Fetal/physiology*
Newborn seizure detection based on heart rate variability

Malarvili MB, Mesbah M

IEEE Trans Biomed Eng, 2009 Nov;56(11):2594-603.
PMID: 19628449 DOI: 10.1109/TBME.2009.2026908

In this paper, we investigate the use of heart rate variability (HRV) for automatic newborn seizure detection. The proposed method consists of a sequence of processing steps, namely, obtaining HRV from the ECG, extracting a discriminating HRV feature set, selecting an optimal subset from the full feature set, and, finally, classifying the HRV into seizure/nonseizure using a supervised statistical classifier. Due to the fact that HRV signals are nonstationary, a set of time-frequency features from the newborn HRV is proposed and extracted. In order to achieve efficient HRV-based automatic newborn seizure detection, a two-phase wrapper-based feature selection technique is used to select the feature subset with minimum redundancy and maximum class discriminability. Tested on ECG recordings obtained from eight newborns with identified EEG seizure, the proposed HRV-based neonatal seizure detection algorithm achieved 85.7% sensitivity and 84.6% specificity. These results suggest that the HRV is sensitive to changes in the cardioregulatory system induced by the seizure, and therefore, can be used as a basis for an automatic seizure detection.

Matched MeSH terms: Heart Rate/physiology*
Fulltext Antepartum fetal heart rate feature extraction and classification using empirical mode decomposition and support vector machine

Krupa N, Ali M, Zahedi E, Ahmed S, Hassan FM

Biomed Eng Online, 2011;10:6.
PMID: 21244712 DOI: 10.1186/1475-925X-10-6

Cardiotocography (CTG) is the most widely used tool for fetal surveillance. The visual analysis of fetal heart rate (FHR) traces largely depends on the expertise and experience of the clinician involved. Several approaches have been proposed for the effective interpretation of FHR. In this paper, a new approach for FHR feature extraction based on empirical mode decomposition (EMD) is proposed, which was used along with support vector machine (SVM) for the classification of FHR recordings as 'normal' or 'at risk'.

Matched MeSH terms: Heart Rate, Fetal/physiology*
Anthropometric and physiological profiles of sepak takraw players

Jawis MN, Singh R, Singh HJ, Yassin MN

Br J Sports Med, 2005 Nov;39(11):825-9; discussion 825-9.
PMID: 16244191

OBJECTIVES: Anthropometric and physiological profiles of national sepak takraw players were determined.
METHODS: Thirty nine players, specialising in the three playing positions (tekong/server, feeder, and killer/spiker) were divided into three age categories of under 15 (U15), under 18 (U18), and under 23 (U23) years of age. Height, weight, percent body fat (%bf), maximum oxygen consumption (Vo(2max)), range of motion (ROM), back and leg strength, and heart rate, for the estimation of oxygen consumption during matches, were recorded. Statistical analysis was performed using one way ANOVA for independent measurements and data are presented as mean+/-standard deviation.
RESULTS: The U23 players were significantly taller and heavier with significantly better ROM of the neck, trunk, and ankle joints and back and leg strength than the U15 players. No significant difference was found in %bf between the three age categories. Mean maximum heart rate during exercise was significantly higher in the U15 group when compared to the U18 and U23 groups (p<0.05). Mean Vo2max was similar between the three groups. Estimated oxygen consumption during matches was 69.1%, 68.5%, and 56.4% of Vo2max in the killer, tekong, and the feeder groups, respectively.
CONCLUSIONS: The mean height, body weight, and cardiopulmonary capacities of the players were within the Malaysian population norms, but were somewhat lower than those of players of other court games from other countries. %bf was also lower in these players. This study provides the much needed anthropometric and physiological data of sepak takraw players for further development of this sport.

Matched MeSH terms: Heart Rate/physiology
Method optimization to assess endothelial function in females-duration of glyceryl trinitrate effect

Ibrahim NN, Rasool AH, Wong AR, Rahman AR

Methods Find Exp Clin Pharmacol, 2007 Jun;29(5):349-52.
PMID: 17805437

Pulse-wave analysis (PWA) combined with pharmacological challenges has recently been used as a method to measure endothelial function. This involved administration of glyceryl trinitrate (GTN), followed by salbutamol as endothelium-independent and -dependent vasodilators, respectively. The duration of GTN effect needs to be established before the administration of salbutamol. Baseline augmentation index (AIx) and pulse-wave velocity (PWV) measurements were taken in 11 healthy female subjects (mean age 23.27 +/- 3.66 years). Sublingual GTN 0.5 mg was administered for 3 min, followed by AIx and PWV measurements every 5 min till 20 min and then every 10 min until 40 min post-GTN. Maximum change in AIx post-GTN was at 3 min with a mean change from the baseline of -17.86% +/- 4.40% (p < 0.001). There were no significant changes noted after 30 and 40 min with mean change being -0.82% +/- 2.61% and 0.14% +/- 3.20%, respectively (p > 0.05). Significant changes in PWV were noted at 5 and 10 min with the mean change of -0.33 +/- 0.36 m/s and -0.33 +/- 0.35 m/s, respectively (p = 0.01). There were no further changes noted at 15 min and thereafter (p > 0.05). A duration of at least 30 min after GTN is required for AIx and PWV values to reach their baseline. Thus, the administration of salbutamol should be given only after 30 min of sublingual GTN for the assessment of endothelial function.

Matched MeSH terms: Heart Rate/drug effects
Fulltext Validation and Calibration for Embedding Rating of Perceived Exertion Into High-Intensity Interval Exercise in Adolescents: A Lab-Based Study

Liu Y, Williams CA, Weston KL, Duncombe SL, Malik AA, Barker AR

Pediatr Exerc Sci, 2025 Feb 01;37(1):11-17.
PMID: 38194950 DOI: 10.1123/pes.2023-0084

PURPOSE: Rating of perceived exertion (RPE) is a convenient and cost-effective tool that can be used to monitor high-intensity interval exercise (HIIE). However, no methodological study has demonstrated the validity of RPE in this context. Therefore, the aim of this study was to validate and calibrate RPE for monitoring HIIE in adolescents.
METHODS: RPE, heart rate (HR), and oxygen uptake (V˙O2) data were retrospectively extracted from 3 lab-based crossover studies, with a pooled sample size of 45 adolescents, performing either cycling-based or running-based HIIE sessions. Within-participant correlations were calculated for RPE-HR and RPE-V˙O2, and receiver operator characteristic curve analysis was used to establish RPE cut points.
RESULTS: The results showed that RPE-HR demonstrated acceptable criterion validity (r = .53-.74, P < .01), while RPE-V˙O2 had poor validity (r = .40-.48, P < .01), except for HIIE at 100% peak power (r = .59, P < .01). RPE cut points of 4 and 5 were established in corresponding to HR/V˙O2 based thresholds.
CONCLUSION: RPE has some utility in evaluating intensity during lab-based running or cycling HIIE in adolescents. Future studies should expand the validation and calibration of RPE for prescribing and monitoring HIIE in children and adolescents in field-based contexts.

Matched MeSH terms: Heart Rate*
Fulltext The effect of wearing sanitary napkins of different thicknesses on physiological and psychological responses in Muslim females

Mohamed NG, Abidin NZ, Law KS, Abe M, Suzuki M, Muhamed AM, et al.

J Physiol Anthropol, 2014;33:28.
PMID: 25189184 DOI: 10.1186/1880-6805-33-28

Menstruation is associated with significant unpleasantness, and wearing a sanitary napkin (SN) during menses causes discomfort. In addition, many Muslim women use a thick type of SN during menses due to the religious requirement that even disposable SNs be washed before disposal. Therefore, the objective of this study was to measure the physiological and psychological responses to wearing SNs of different thicknesses during menstruation and non-menstruation phases at rest and during physical activity/exercise among Muslim women.

Matched MeSH terms: Heart Rate/physiology*
The effects of modified exponential tapering technique on perceived exertion, heart rate, time trial performance, VO2max and power output among highly trained junior cyclists

Ishak A, Hashim HA, Krasilshchikov O

J Sports Med Phys Fitness, 2016 Sep;56(9):961-7.
PMID: 26004044

BACKGROUND: The present study investigated the effects of a 2-week modified exponential taper on physiological adaptation and time trial performance among junior cyclists.
METHODS: Participants (N.=27) with the mean age of 16.95±0.8 years, height of 165.6±6.1 cm and weight of 54.19±8.1 kg were matched into either modified exponential taper (N.=7), normal exponential taper (N.=7), or control (N.=7) groups using their initial VO2max values. Both experimental groups followed a 12-week progressive endurance training program and subsequently, a 2-week tapering phase. A simulated 20-km time trial performance along with VO2max, power output, heart rate and rating of perceived exertion were measured at baseline, pre and post-taper. One way ANOVA was used to analyze the difference between groups before the start of the intervention while mixed factorial ANOVA was used to analyze the difference between groups across measurement sessions. When homogeneity assumption was violated, the Greenhouse-Geisser Value was used for the corrected values of the degrees of freedom for the within subject factor the analysis.
RESULTS: Significant interactions between experimental groups and testing sessions were found in VO2max (F=6.67, df=4, P<0.05), power output (F=5.02, df=4, P<0.05), heart rate (F=10.87, df=2.51, P<0.05) rating of perceived exertion (F=13.04, df=4, P<0.05) and 20KM time trial (F=4.64, df=2.63, P<0.05). Post-hoc analysis revealed that both types of taper exhibited positive effects compared to the non-taper condition in the measured performance markers at post-taper while no different were found between the two taper groups.
CONCLUSIONS: It was concluded that both taper protocols successfully inducing physiological adaptations among the junior cyclists by reducing the volume and maintaining the intensity of training.

Matched MeSH terms: Heart Rate/physiology*
Improving detection of obstructive sleep apnoea by overnight oximetry in children using pulse rate parameters

Sahadan DZ, Davey MJ, Horne RS, Nixon GM

Sleep Breath, 2015 Dec;19(4):1409-14.
PMID: 25739713 DOI: 10.1007/s11325-014-1108-4

PURPOSE: Overnight oximetry is a simple tool for investigation of obstructive sleep apnoea (OSA) in children, but only severe cases will be detected, and children with obstructive events resulting in arousal, but not desaturation, will have a normal (inconclusive) result. We hypothesised that pulse rate rises using pulse rate indices per hour (PRI) and pulse rate standard deviation (PR-SD) automatically calculated from commercially available software would improve oximetry as a diagnostic tool.
METHODS: Children having home overnight oximetry for suspected OSA were identified over 12 months, and those with a normal result who went on to have polysomnography (PSG) were included. Oximetry, including PR-SD and PRI (rises of 8, 10 and 15 beats/min per hour), was analyzed using commercially available software. PR parameters were compared between those with OSA (obstructive apnoea-hypopnoea index (OAHI) >1 event/h) and those without OSA.
RESULTS: One hundred sixteen children had normal oximetry, of whom 93 (median age 4.5 years; 55 % M) had PSG. Fifty-seven of 93 (61 %) children had OSA (median OAHI 4.5 events/h, range 1.1-24). PR-SD was not different between the OSA and non-OSA groups (p = 0.87). PRI tended to be higher in those with OSA, but there was considerable overlap between the groups: PRI-8 (mean ± SD 58.5 ± 29.0/h in OSA group vs 48.6 ± 20.2/h in non-OSA group, p = 0.07), PRI-10 (45.1 ± 25.0 vs 36.2 ± 16.7, p = 0.06) and PRI-15 (24.4 ± 14.5 vs 18.9 ± 9.0, p = 0.04). A PRI-15 threshold of >35/h had specificity of 97 % for OSA.
CONCLUSION: The PRI-15 shows promise as an indicator of OSA in children with normal oximetry.

Matched MeSH terms: Heart Rate*
Obesity depresses baroreflex control of renal sympathetic nerve activity and heart rate in Sprague Dawley rats: role of the renal innervation

Khan SA, Sattar MZ, Abdullah NA, Rathore HA, Abdulla MH, Ahmad A, et al.

Acta Physiol (Oxf), 2015 Jul;214(3):390-401.
PMID: 25846561 DOI: 10.1111/apha.12499

AIM:
This study investigated the role of the renal innervation in arterial and cardiopulmonary baroreflex regulation of renal sympathetic nerve activity (RSNA) and heart rate (HR) in rats fed a high-fat diet to induce obesity.

METHODS:
Rats received either a normal (12% kcal) or high (45% kcal) fat diet for 60 days. On day 61, rats were anesthetized and prepared for recording left RSNA. In one group, the renal nerves remained intact, while in the other, both kidneys were denervated. Baroreflex gain curves for RSNA and HR were generated by increasing and decreasing blood pressure. Low-pressure baroreceptors were challenged by infusing a saline load.

RESULTS:
Mean blood pressure was 135 mmHg in the fat-fed and 105 mmHg (P < 0.05) in normal rats. Weight gain, adiposity index and creatinine clearance were 37, 82 and 55% higher (P < 0.05-0.001), but urine flow rate and fractional sodium excretions were 53 and 65% (both P < 0.001) lower, respectively, in the fat-fed compared to normal rats. In fat-fed rats with innervated kidneys, RSNA and HR arterial baroreflex sensitivities were reduced by 73 and 72% (both P < 0.05) but were normal in renally denervated rats. Volume expansion decreased RSNA by 66% (P < 0.001) in normal rats, but not in the intact fat-fed rats and by 51% (P < 0.01) in renally denervated fat-fed rats.

CONCLUSION:
Feeding a high-fat diet caused hypertension associated with dysregulation of the arterial and cardiopulmonary baroreflexes which was dependent on an intact renal innervation. This suggests that in obese states neural signals arising from the kidney contribute to a deranged autonomic control.

KEYWORDS:
baroreflex gain curves; cardiopulmonary reflex; high-fat diet

Matched MeSH terms: Heart Rate*
Automated identification of normal and diabetes heart rate signals using nonlinear measures

Rajendra Acharya U, Faust O, Adib Kadri N, Suri JS, Yu W

Comput Biol Med, 2013 Oct;43(10):1523-9.
PMID: 24034744 DOI: 10.1016/j.compbiomed.2013.05.024

Diabetes mellitus (DM) affects considerable number of people in the world and the number of cases is increasing every year. Due to a strong link to the genetic basis of the disease, it is extremely difficult to cure. However, it can be controlled to prevent severe consequences, such as organ damage. Therefore, diabetes diagnosis and monitoring of its treatment is very important. In this paper, we have proposed a non-invasive diagnosis support system for DM. The system determines whether or not diabetes is present by determining the cardiac health of a patient using heart rate variability (HRV) analysis. This analysis was based on nine nonlinear features namely: Approximate Entropy (ApEn), largest Lyapunov exponet (LLE), detrended fluctuation analysis (DFA) and recurrence quantification analysis (RQA). Clinically significant measures were used as input to classification algorithms, namely AdaBoost, decision tree (DT), fuzzy Sugeno classifier (FSC), k-nearest neighbor algorithm (k-NN), probabilistic neural network (PNN) and support vector machine (SVM). Ten-fold stratified cross-validation was used to select the best classifier. AdaBoost, with least squares (LS) as weak learner, performed better than the other classifiers, yielding an average accuracy of 90%, sensitivity of 92.5% and specificity of 88.7%.

Matched MeSH terms: Heart Rate/physiology*
Two-week test-retest reliability of the Polar® RS800CX™ to record heart rate variability

Williams DP, Jarczok MN, Ellis RJ, Hillecke TK, Thayer JF, Koenig J

Clin Physiol Funct Imaging, 2017 Nov;37(6):776-781.
PMID: 26815165 DOI: 10.1111/cpf.12321

Recently, research has validated the use of Polar® heart rate monitors as a tool to index heart rate variability (HRV). In the current investigation, we sought to evaluate the test-retest reliability of both time and frequency domain measures of HRV using the Polar® RS800CX™ . Continuous HRV data were collected as 60 nominally healthy adults underwent a resting and orthostatic stress test. We evaluated reproducibility by means of the interclass correlation coefficient for absolute agreement and consistency, and the standard error of measurement. We found moderate reliable 2-week test-retest reliability of HRV using the Polar® RS800CX™ , results that are in line with previous studies that have validated the stability of HRV using other methods of measurement (e.g. electrocardiogram). Additionally, when examining different methods of spectral density estimation, we found that using the auto-regressive transformation method provides the most stable indices of HRV. Taken together, our results suggest that the Polar® RS800CX™ is not only a valid method to record HRV, but also a reliable one, particularly when using the auto-regressive transformation method.

Matched MeSH terms: Heart Rate*
CT coronary angiogram in children with Kawasaki patients: experience in 52 patients

Borhanuddin BK, Abdul Latiff H, Mohamed Yusof AK

Cardiol Young, 2022 Dec;32(12):1994-1998.
PMID: 35707919 DOI: 10.1017/S1047951122000154

BACKGROUND: CT is an accepted non-invasive imaging tool to assess the coronary arteries in adults; however, its utilisation in children is limited by high heart rate and lack of standardised protocol. We sought to assess diagnostic quality and factors that affect image quality of CT in assessing coronary artery lesions in Kawasaki patients less than 18 years of age.
METHODOLOGY: CT coronary angiography was performed on patients with Kawasaki disease diagnosed with coronary aneurysm or suspected to have coronary stenosis. Studies were performed using electrocardiogram-gated protocols. General anaesthesia was used in patients who were not cooperative for breathing control. Heart rate, image quality, and effective radiation dose were documented.
RESULTS: Fifty-two Kawasaki patients underwent CT coronary angiography to assess coronary artery lesions. Median heart rate was 88 beats per minute (range 50-165 beats/minute). Image quality was graded as excellent in 34 (65%) patients, good in 17 (32%), satisfactory in 1, and poor in 1 patient. Coronary artery aneurysm was found in 25 (bilateral = 6, unilateral = 19, multiple = 11). Thrombus was found in 11 patients resulting in partial and total occlusion in 8 and 3 patients, respectively. Coronary stenosis was noted in 2 patients. The effective radiation dose was 1.296 millisievert (median 0.81 millisievert). Better diagnostic imaging quality was significantly related to lower heart rate (p = 0.007).
CONCLUSION: Electrocardiogram-triggered CT coronary angiography provides a good diagnostic assessment of coronary artery lesions in children with Kawasaki disease.

Matched MeSH terms: Heart Rate/physiology
Development of a zebrafish model for toxicity evaluation of adulterated Apis mellifera honey

Fakhlaei R, Selamat J, Abdull Razis AF, Sukor R, Ahmad S, Khatib A, et al.

Chemosphere, 2024 May;356:141736.
PMID: 38554873 DOI: 10.1016/j.chemosphere.2024.141736

Since ancient times, honey has been used for medical purposes and the treatment of various disorders. As a high-quality food product, the honey industry is prone to fraud and adulteration. Moreover, limited experimental studies have investigated the impact of adulterated honey consumption using zebrafish as the animal model. The aims of this study were: (1) to calculate the lethal concentration (LC50) of acid-adulterated Apis mellifera honey on embryos, (2) to investigate the effect of pure and acid-adulterated A. mellifera honey on hatching rate (%) and heart rate of zebrafish (embryos and larvae), (3) to elucidate toxicology of selected adulterated honey based on lethal dose (LD50) using adult zebrafish and (4) to screen the metabolites profile of adulterated honey from blood serum of adult zebrafish. The result indicated the LC50 of 31.10 ± 1.63 (mg/ml) for pure A. mellifera honey, while acetic acid demonstrates the lowest LC50 (4.98 ± 0.06 mg/ml) among acid adulterants with the highest mortality rate at 96 hpf. The treatment of zebrafish embryos with adulterated A. mellifera honey significantly (p ≤ 0.05) increased the hatching rate (%) and decreased the heartbeat rate. Acute, prolong-acute, and sub-acute toxicology tests on adult zebrafish were conducted at a concentration of 7% w/w of acid adulterants. Furthermore, the blood serum metabolite profile of adulterated-honey-treated zebrafish was screened by LC-MS/MS analysis and three endogenous metabolites have been revealed: (1) Xanthotoxol or 8-Hydroxypsoralen, (2) 16-Oxoandrostenediol, and (3) 3,5-Dicaffeoyl-4-succinoylquinic acid. These results prove that employed honey adulterants cause mortality that contributes to higher toxicity. Moreover, this study introduces the zebrafish toxicity test as a new promising standard technique for the potential toxicity assessment of acid-adulterated honey in this study and hazardous food adulterants for future studies.

Matched MeSH terms: Heart Rate/drug effects
Fulltext The Restorative Effects of Nature Exposure on The Self-Regulation Resources in Mentally Fatigued Soccer Players: A Randomized Controlled Trial

Sun H, Soh KG, Mohammadi A, Toumi Z, Chang R, Jiang J

J Sports Sci Med, 2024 Dec;23(4):882-894.
PMID: 39649572 DOI: 10.52082/jssm.2024.882

Interventions involving exposure to nature can increase self-regulatory resources. However, this improvement has never been examined in mentally fatigued soccer players who have insufficient resources to self-regulate and maintain specific performances. The present study aims to investigate how exposure to nature influences the self-regulation capability of university soccer players who are mentally fatigued. The participants aged 18-24 years (M = 20.73 ± 2.00), with an average training duration of 5.14 ± 1.31 years, were randomly divided into six different groups (three experimental groups and three control groups). Each experimental group was compared with its corresponding control group using three different intervention durations: 4.17 min, 8.33 min, and 12.50 min. A forty-five-minute Stroop task was used to induce mental fatigue, followed by the intervention. The indicators of self-regulation, both physiological (heart rate variability, or HRV) and psychological (competitive state anxiety), were recorded. Experimental Group 3 (12.50 min intervention) only showed significant improvement in HRV (p = 0.008, d = 0.93), competitive state anxiety (cognitive and somatic anxiety p = 0.019, d = 0.86; state confidence p = 0.041, d = 0.797) compared to control group 3. Nature exposure significantly improves self-regulation in mentally fatigued soccer players. Specifically, the 12.50 min intervention showed the greatest improvements in both HRV and competitive state anxiety, suggesting that a longer duration of nature exposure enhances mental restoration more effectively.

Matched MeSH terms: Heart Rate*
Protective effects of pyridoxine, amlodipine, and their combination in a vasopressin-induced angina model in rats

Al-Khawlani MA, Al-Madhagi WM, Sabati AM, ALomaisi SAMA, Al-Najar M

Naunyn Schmiedebergs Arch Pharmacol, 2025 Aug;398(8):10983-10995.
PMID: 40067440 DOI: 10.1007/s00210-025-03905-6

Vitamin B6 (pyridoxine) vitamins are of interest in preventative and protective strategies in cardiovascular disease. However, the safety and efficacy of vitamin B6 has been questioned. The aim of this study was to study the protective effect of pyridoxine, amlodipine, and their combination against vasopressin-induced angina model in rats. The administration of vasopressin (1 IU/kg, i.v.) to the rats elevated the S-wave level of the electrocardiogram reflecting the presence of subendocardial ischemia, whereas it decreased of the heart rate, resulting in the increase of the cardiac enzymes, creatine kinase MB (CK MB), and lactate dehydrogenase (LDH). In the vasopressin-induced angina model, oral administration of pyridoxine in dose of 5, 7, 10 mg/kg revealed dose-dependent suppression of vasopressin-triggered of ST elevation and in reduced of heart rat. In addition, pyridoxine produced dose-dependent suppression of cardiac enzymes, creatine kinase MB (CK MB), and lactate dehydrogenase (LDH) more than amlodipine and isosorbide; while in contrast, the combination of pyridoxine with amlodipine resulted in a trend towards increased adverse cardiovascular events; pyridoxine in dose 7 mg/kg was found to be more potent than pyridoxine in doses 5, 10 mg/kg, amlodipine and isosorbide on vasopressin-induced angina in rats. Pyridoxine in dose of (5, 7 mg) prevents cardiac necrosis and artery well thickened on vasopressin-induced angina modal. Pyridoxine's protective effects may be mediated by improved endothelial nitric oxide synthase (eNOS) function, reduction of homocysteine levels, and modulation of sympathetic activity. Pyridoxine at optimal doses shows promise as a novel therapeutic agent for coronary heart disease prevention, warranting further investigation into its potential clinical applications.

Matched MeSH terms: Heart Rate/drug effects
Role of supraspinal vasopressin neurones in the effects of atrial natriuretic peptide on sympathetic nerve activity

Yusof AP, Yusoff NH, Suhaimi FW, Coote JH

Auton Neurosci, 2009 Jun 15;148(1-2):50-4.
PMID: 19349212 DOI: 10.1016/j.autneu.2009.03.005

The aim of the present study was to determine if paraventricular-spinal vasopressin neurones participate in the sympatho-inhibitory effects of systemically administered atrial natriuretic peptide (ANP) on renal sympathetic nerve activity (RSNA). Experiments were carried out on male Sprague-Dawley rats anesthetized with 1.3 g/kg urethane. Changes in mean arterial pressure (mm Hg), heart rate (beats per minute) and RSNA (%) were measured following intravenous bolus administration of ANP (250 ng, 500 ng and 5 microg). Intrathecal application of selective V 1a receptor antagonist was performed to test for the involvement of supraspinal vasopressin pathways in mediating the effect on sympathetic outflow evoked by intravenous ANP administration. The results obtained demonstrated that both low and high doses of ANP caused renal sympathoinhibition (250 ng; - 7.5 +/- 1%, 500 ng; - 14.2 +/- 1%, 5 microg; - 16.4 +/- 2%), concomitant with vasodilation and bradycardia. After spinal vasopressin receptor blockade, the inhibitory effects of ANP were prevented and there was a small renal sympatho-excitation (250 ng; + 1.7 +/- 0.2%, 500 ng; + 6.1 +/- 0.03%, 5 microg; + 8.0 +/- 0.03%, P < 0.05). Therefore, the renal sympathetic nerve inhibition elicited by circulating ANP is dependent on the efficacy of a well established supraspinal vasopressin pathway. Since supraspinal vasopressin neurones without exception excite renal sympathetic neurones, it is suggested that ANP elicits this effect by activating cardiac vagal afferents that inhibit the spinally projecting vasopressin neurones at their origin in the paraventricular nucleus of the hypothalamus.

Matched MeSH terms: Heart Rate/drug effects; Heart Rate/physiology
Evaluation of a technique to measure heart rate variability in anaesthetised cats

Khor KH, Shiels IA, Campbell FE, Greer RM, Rose A, Mills PC

Vet J, 2014 Feb;199(2):229-35.
PMID: 24321367 DOI: 10.1016/j.tvjl.2013.11.006

Analysis of heart rate (HR) and heart rate variability (HRV) are powerful tools to investigate cardiac diseases, but current methods, including 24-h Holter monitoring, can be cumbersome and may be compromised by movement artefact. A commercially available data capture and analysis system was used in anaesthetised healthy cats to measure HR and HRV during pharmacological manipulation of HR. Seven healthy cats were subjected to a randomised crossover study design with a 7 day washout period between two treatment groups, placebo and atenolol (1mg/kg, IV), with the efficacy of atenolol to inhibit β1 adrenoreceptors challenged by epinephrine. Statistical significance for the epinephrine challenge was set at P<0.0027 (Holm-Bonferroni correction), whereas a level of significance of P<0.05 was set for other variables. Analysis of the continuous electrocardiography (ECG) recordings showed that epinephrine challenge increased HR in the placebo group (P=0.0003) but not in the atenolol group. The change in HR was greater in the placebo group than in the atenolol group (P=0.0004). Therefore, compared to cats pre-treated with placebo, pre-treatment with atenolol significantly antagonised the tachycardia while not significantly affecting HRV. The increased HR in the placebo group following epinephrine challenge was consistent with a shift of the sympathovagal balance towards a predominantly sympathetic tone. However, the small (but not significant at the critical value) decrease in the normalised high-frequency component (HFnorm) in both groups of cats suggested that epinephrine induced a parasympathetic withdrawal in addition to sympathetic enhancement (increased normalised low frequency component or LFnorm). In conclusion, this model is a highly sensitive and repeatable model to investigate HRV in anaesthetised cats that would be useful in the laboratory setting for short-term investigation of cardiovascular disease and subtle responses to pharmacological agents in this species.

Matched MeSH terms: Heart Rate/drug effects*; Heart Rate/physiology*
Fulltext Coughing Shih Tzu dog due to myxomatous mitral valve disease stage C2

Khor, K.H., Jessie-Bay, J.X.

Jurnal Veterinar Malaysia, 2018;30(1):15-19.
MyJurnal

Myxomatous Mitral Valve Disease is a degenerative condition of the mitral valves leaflets. A 10-year-old
male castrated Shih Tzu was presented with primary complaint of coughing. Clinical examination revealed normal
heart rate, respiratory rate and rectal temperature. Systolic murmur Grade IV/VI was heard at the left heart apex.
Thoracic radiographic findings were cardiomegaly with the vertebral heart score of 11.0 and had evidence of
cardiogenic pulmonary edema. Echocardiographic examination revealed thickening mitral valves with evidence of
moderate regurgitation observed. Based on the findings obtained, the dog was diagnosed with Myxomatous Mitral
Valve disease stage C2. Dog was treated with benazepril (0.5mg/kg), pimobendan (0.2mg/kg) with a combination of
furosemide (2mg/kg). Frusemide was gradually removed from the treatment regime as coughing improved over time.
The dog was no longer lethargy and even gained weight.

Matched MeSH terms: Heart Rate

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