MyMedR

Displaying publications 81 - 100 of 262 in total

Abstract:

Sort:

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
Fast prototype of a wireless cardiac rhythm interpretive instrument

Wong KI, Ho MM

Annu Int Conf IEEE Eng Med Biol Soc, 2008;2008:502-5.
PMID: 19162703 DOI: 10.1109/IEMBS.2008.4649200

Extended patient monitoring has become increasingly important for detection of cardiac conditions, such as irregularities in the rhythms of the heart, while patient is practicing normal daily activity. This paper presents a design of a single lead wireless cardiac rhythm interpretive instrument that capable of capture the electrocardiogram (ECG) in digital format and transmitted to a remote base-station (i.e. PC) for storage and further interpretation. The design has achieved high quality of ECG and free of interference in the presence of motion.

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
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
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*
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*
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*
Fulltext Blood pressure, body mass index, heart rate and levels of blood cholesterol and glucose of volunteers during National Heart Weeks, 1995-1997

Khoo KL, Tan H, Liew YM, Sambhi JS, Aljafri AM, Hatijah A

Med J Malaysia, 2000 Dec;55(4):439-50.
PMID: 11221155

The paper presents the results of a health screening programme conducted in 10 major centers in Malaysia--Kuala Lumpur, Penang, Ipoh, Johor Bahru, Alor Star, Kuala Terengganu, Malacca, Kota Bahru, Kuching and Kota Kinabalu during the National Heart Weeks, 1995-1997. There were 6,858 participants of both sexes aged between 6 years to 81 years old. The parameters involved in the screening programme were body mass index, blood pressure, heart rate, cholesterol and glucose. The following are the results of the study:- 1. The mean and standard deviation for the body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), total cholesterol (TC) and non fasting (random) blood glucose (GL) of the volunteers studied were 24.3 +/- 4.0 kg/m2, 128.3 +/- 21.1 mmHg, 79.6 +/- 11.9 mmHg, 77.2 +/- 12.1 bpm, 5.33 +/- 1.37 mmol/l and 5.11 +/- 1.97 mmol/l respectively. 2. There was a rising trend for BMI, SBP, DBP, TC and GL with age. The HR was higher in the younger age group of those below 20 years. Males tended to have higher mean values than females except for HR which was similar in both sexes. 3. The Malays, Chinese and Indians seemed to have closely similar mean values for SBP, DBP and HR but the Indians possessed the highest BMI (25.62 +/- 3.90 kg/m2), TC (5.61 +/- 1.48 mmol/l) and GL (5.41 +/- 2.43 mmol/l) among the three major ethnic groups. While the Ibans had highest TC (6.07 + 1.09 mmol/l), their GL level was the lowest (4.76 +/- 1.15 mmol/l). The Kadazans had the lowest TC level (4.94 +/- 1.39 mmol/l) among all the ethnic groups. 4. Among the participants screened, 31.9% were overweight (BMI > or = 25), 7.6% were obese (BMI > or = 30); 26.8% had raised SBP (> or = 140 mmHg) and 19.3% had raised DBP (> or = 90 mmHg); 13.6% of the participants had increased HR (> or = 90 bpm), 22% had raised TC (> or = 6.20 mmol/l) and 2% had raised GL (> or = 11.00 mmol/l). There was a higher prevalence for abnormal values with increasing age until between the ages of 60 or 70 years, when the values began to fall. 5. Age was positively correlated with SBP (r = 0.41***, df = 4351), DBP (r = 0.27***, df = 4351), TC (r = 0.22***, df = 3303) and GL (r = 0.16***, df = 2442) but negatively correlated with HR (r = -0.13***, df = 4351). The BMI was positively correlated with SBP (r = 0.29***, df = 2769), DBP (r = 0.31***, df = 2769), TC (r = 0.16***, df = 2137) and GL (r = 0.11**, df = 1637) but there was no correlation with HR (r = 0.03NS, df = 2771). The SBP and DBP were highly correlated with each other (r = 0.75***, df = 4351) and they also showed highly significant positive correlation (r = 0.08***-0.13***, df = 2441-3301) with TC and GL. TC was positively correlated with GL (r = 0.05* df = 2319) but only at the 5% probability level.

Matched MeSH terms: Heart Rate*
Fulltext Spread of spinal anaesthesia with 0.5% bupivacaine: influence of the vertebral interspace and speed of injection

Chin KW, Chin NM, Chin MK

Med J Malaysia, 1994 Jun;49(2):142-8.
PMID: 8090093

Three millilitres of plain 0.5% bupivacaine were injected intrathecally at two different spinal interspaces (L2/3 and L4/5) and at two different speeds (15 and 30 sec) in four groups of ten patients. Injection at L2/3 over 15 sec produced a significantly higher mean maximum spread of analgesia (T6.4) when compared to injection at L4-5 over 15 sec (T10.3) (P < 0.05). Over the same interspace L2/3, injection over 15 sec also produced a higher level of spread as compared to the 30 sec group (p < 0.05). At 15 min there was a greater fall in blood pressure in the L2/3 15 sec group when compared to the other groups (p < 0.01). There was a further decrease in the blood pressure in L2/3 15 sec and L4/5 30 sec groups after 30 minutes of blockade (p < 0.01). Therefore close monitoring of cardiovascular parameters must be continued for at least 30 min in spinal anaesthesia with bupivacaine.

Matched MeSH terms: Heart Rate/drug effects
Cardiovascular effects in the rat of dihydrocorynantheine isolated from Uncaria callophylla

Chang P, Koh YK, Geh SL, Soepadmo E, Goh SH, Wong AK

J Ethnopharmacol, 1989 Apr;25(2):213-5.
PMID: 2747255
Matched MeSH terms: Heart Rate/drug effects
Fulltext Cardiovascular and metabolic responses to isometric exercise of athletes and non-athletes

Rajikin MH

Med J Malaysia, 1980 Sep;35(1):46-52.
PMID: 6973059

Seven non-anthletes [21-26 yrs] and five athletes [23-29 yrs] have participated in the study of cardiovascular and metabolic responses to 15 minutes isometric leg exercise at 15% of each of their maximal voluntary contraction force [MVC]. Oxygen consumption [V02 ]. heart rate [HR] and blood pressure (BP]. were measured during resting. exercise and recovery! periods. The results show that there were a significant increase in V02. HR and BP of the two groups studied during exercise, but no significant difference between groups has been found. This study indicates that although cardiovascular response between the rwo groups was not significantly different, 15 minutes isometric leg exercise at 15% MVC has challenged this system in a such a way to fulfill the metabolic requirement of the
working muscle ill both groups. This finding was
discussed in light of the available literatures.

Matched MeSH terms: Heart Rate*
Heart rate variability and baroreflex sensitivity abnormalities in Guillain-Barré syndrome: a pilot study

Tan CY, Shahrizaila N, Yeoh KY, Goh KJ, Tan MP

Clin Auton Res, 2019 06;29(3):339-348.
PMID: 29654380 DOI: 10.1007/s10286-018-0525-z

OBJECTIVE: The current study aimed to investigate autonomic dysfunction in Guillain-Barré syndrome (GBS) patients and describe the results of computational heart rate variability (HRV)/baroreflex sensitivity (BRS) and autonomic challenge tests.
METHODS: GBS patients were consecutively recruited and the results were compared to age- and gender-matched healthy controls. A series of autonomic function tests including computation-dependent tests (power spectrum analysis of HRV and BRS at rest) and challenge maneuvers (deep breathing, eyeball compression, active standing, the Valsalva maneuver, sustained handgrip, and the cold pressor test) were performed.
RESULTS: Ten GBS patients (six men; mean age = 40.1 ± 13.9 years) and ten gender- and age-matched healthy controls were recruited. The mean GBS functional grading scale at disease plateau was 3.4 ± 1.0. No patients required intensive care unit admission or mechanical ventilation. Low-frequency HRV (p = 0.027), high-frequency HRV (p = 0.008), and the total power spectral density of HRV (p = 0.015) were significantly reduced in patients compared to controls. The mean up slope (p = 0.034), down slope (p = 0.011), and total slope (p = 0.024) BRS were significantly lower in GBS patients. The diastolic rise in blood pressure in the cold pressor test was significantly lower in GBS patients compared to controls (p = 0.008).
INTERPRETATION: Computation-dependent tests (HRV and BRS) were more useful for detecting autonomic dysfunction in GBS patients, whereas the cold pressor test was the only reliable challenge test, making it useful as a bedside measure of autonomic function in GBS patients.

Matched MeSH terms: Heart Rate/physiology*
Perceptual and Cardiorespiratory Responses to High-Intensity Interval Exercise in Adolescents: Does Work Intensity Matter?

Malik AA, Williams CA, Weston KL, Barker AR

J Sports Sci Med, 2019 03;18(1):1-12.
PMID: 30787646

High-intensity interval exercise (HIIE) may not elicit prominent unpleasant feelings even with elevated perceived exertion and physiological stress in adolescents. However, the influence of different HIIE work intensities on the affective experience and cardiorespiratory responses is unknown. This study examined the acute affective, enjoyment, perceived exertion and cardiorespiratory responses to HIIE with different work intensities in adolescents. Participants (n = 16; 8 boys; age 12.0 ± 0.3 years) performed, on separate days, HIIE conditions consisting of 8 x 1-minute work-intervals at 70%, 85%, or 100% peak power separated by 75 seconds recovery at 20 W. Affect, enjoyment and rating of perceived exertion (RPE) were recorded before, during, and after HIIE. Heart rate (HR) and oxygen uptake were collected during HIIE. Affect declined in all conditions (p < 0.01) but 100%HIIE elicited significantly lower affect than 70%HIIE and 85%HIIE at work-interval 8 (all p < 0.02, ES > 1.74; 70%HIIE = 2.5 ± 0.8; 85%HIIE = 1.1 ± 1.5; 100%HIIE = -1.5 ± 1.4 on feeling scale). Similar enjoyment was evident during and after all conditions (all p > 0.44). RPE was significantly higher during 100%HIIE than 70%HIIE and 85%HIIE across all work-intervals (all p < 0.01, ES > 1.56). The majority of the participants attained ≥90%HRmax during 85%HIIE (87%) and 100%HIIE (100%), but not during 70%HIIE (6%). Affect responses during HIIE are dependent on the intensity of the work-interval and are not entirely negative (unpleasant feelings). Despite similar enjoyment, positive affect experienced during 70%HIIE and 85%HIIE could serve as a strategy to encourage exercise adoption and adherence in adolescents, but only 85%HIIE elicits sufficient HR stimulus to facilitate potential health benefits.

Matched MeSH terms: Heart Rate/physiology
The impact of heart rate-based drowsiness monitoring on adverse driving events in heavy vehicle drivers under naturalistic conditions

Wolkow AP, Rajaratnam SMW, Wilkinson V, Shee D, Baker A, Lillington T, et al.

Sleep Health, 2020 06;6(3):366-373.
PMID: 32340910 DOI: 10.1016/j.sleh.2020.03.005

OBJECTIVES: This study examined the influence of a wrist-worn heart rate drowsiness detection device on heavy vehicle driver safety and sleep and its ability to predict driving events under naturalistic conditions.
DESIGN: Prospective, non-randomized trial.
SETTING: Naturalistic driving in Malaysia.
PARTICIPANTS: Heavy vehicle drivers in Malaysia were assigned to the Device (n = 25) or Control condition (n = 34).
INTERVENTION: Both conditions were monitored for driving events at work over 4-weeks in Phase 1, and 12-weeks in Phase 2. In Phase 1, the Device condition wore the device operated in the silent mode (i.e., no drowsiness alerts) to examine the accuracy of the device in predicting driving events. In Phase 2, the Device condition wore the device in the active mode to examine if drowsiness alerts from the device influenced the rate of driving events (compared to Phase 1).
MEASUREMENTS: All participants were monitored for harsh braking and harsh acceleration driving events and self-reported sleep duration and sleepiness daily.
RESULTS: There was a significant decrease in the rate of harsh braking events (Rate ratio = 0.48, p

Matched MeSH terms: Heart Rate/physiology*
Effects of alternate nostril breathing exercise on cardiac functions in healthy young adults leading a stressful lifestyle

Jahan I, Begum M, Akhter S, Islam Z, Haque M, Jahan N

J Popul Ther Clin Pharmacol, 2020 06 11;27(2):e68-e77.
PMID: 32543162 DOI: 10.15586/jptcp.v27i2.675

Alternate nostril breathing (ANB) is one of the best and easiest breathing exercises. ANB exercise has beneficial effects on cardiac function in healthy and diseased people. The objectives of this study were to assess the effects of ANB exercise on cardiac physiology among healthy medical students. This was a prospective interventional study that was conducted in the Department of Physiology, Chittagong Medical College (CMC), Chattogram, Bangladesh, from July 2017 to June 2018. A total of 100 research participants (RPs) aged 18-20 years, Year-I medical students of CMC, were selected. A simple random sampling method was adopted. The selection was done after the inclusion and exclusion criteria were applied. The age and body mass index (BMI) of the RPs were analogous in both the control and experimental groups. Cardiac parameters, like pulse and blood pressure (BP), were measured. The initial baseline data were recorded for both groups and after 4 weeks. The research respondents of the experimental group performed ANB exercise for 4 weeks. The mean value pulse and BP were significantly (p < 0.001) changed after breathing exercise, compared to the values before the breathing exercise. The results of this study suggest that cardiac function significantly improves after the breathing exercise. Therefore, ANB can be recommended for increasing cardiac efficiency.

Matched MeSH terms: Heart Rate/physiology
Toxicity of the venom of the sea-snake, Laticauda colubrina, with observations on a Malay "folk cure"

Levey HA

Toxicon, 1969 May;6(4):269-76.
PMID: 5805121
Matched MeSH terms: Heart Rate/drug effects
Fulltext Effects of alternate nostril breathing exercise on cardiorespiratory functions in healthy young adults

Jahan I, Begum M, Akhter S, Islam MZ, Jahan N, Samad N, et al.

Ann Afr Med, 2021 7 3;20(2):69-77.
PMID: 34213471 DOI: 10.4103/aam.aam_114_20

Introduction: Alternate nostril breathing (ANB) is an effective breathing exercise with therapeutic benefits on cardiorespiratory functions for healthy and diseased individuals. This study was conducted to assess the effects of ANB exercise on cardiorespiratory tasks in healthy adults.
Materials and Methods: This randomized experimental study was conducted in the Department of Physiology, Chittagong Medical College, Chattogram, from July 2017 to June 2018. A total of 100 1st-year students, aged between 18 and 20 years, were included by a random sampling method. Fifty participants (25 males and 25 females) were enrolled in the experimental group, while age- and body mass index-matched another 50 participants (25 males and 25 females) served as the control group. Experimental group participants performed ANB exercise for 4 weeks. Cardiorespiratory parameters (pulse rate, blood pressure, forced vital capacity, forced expiratory volume in 1st s [FEV1], and peak expiratory flow rate [PEFR] were measured. Data were taken at the start and after 4 weeks in both groups.
Results: Independent t-test showed no significant differences in the cardiorespiratory functions between the experimental and control groups among the male and female participants, except for the females' PEFR which showed small differences. On the other hand, repeated measure ANOVA shows significant improvement in the experimental groups among males (P < 0.001-0.028) and females (P < 0.001-0.001) in all the cardiorespiratory functions measured, except for the FEV1 and PEFR among males.
Conclusion: The results of this study suggest that cardiorespiratory functions were improved after breathing exercise, and therefore, ANB can be recommended for increasing cardiorespiratory efficiency.

Matched MeSH terms: Heart Rate/physiology*
Atrial fibrillation classification and association between the natural frequency and the autonomic nervous system

Abdul-Kadir NA, Mat Safri N, Othman MA

Int J Cardiol, 2016 Nov 01;222:504-8.
PMID: 27505342 DOI: 10.1016/j.ijcard.2016.07.196

BACKGROUND: The feasibility study of the natural frequency (ω) obtained from a second-order dynamic system applied to an ECG signal was discovered recently. The heart rate for different ECG signals generates different ω values. The heart rate variability (HRV) and autonomic nervous system (ANS) have an association to represent cardiovascular variations for each individual. This study further analyzed the ω for different ECG signals with HRV for atrial fibrillation classification.
METHODS: This study used the MIT-BIH Normal Sinus Rhythm (nsrdb) and MIT-BIH Atrial Fibrillation (afdb) databases for healthy human (NSR) and atrial fibrillation patient (N and AF) ECG signals, respectively. The extraction of features was based on the dynamic system concept to determine the ω of the ECG signals. There were 35,031 samples used for classification.
RESULTS: There were significant differences between the N & NSR, N & AF, and NSR & AF groups as determined by the statistical t-test (p<0.0001). There was a linear separation at 0.4s(-1) for ω of both databases upon using the thresholding method. The feature ω for afdb and nsrdb falls within the high frequency (HF) and above the HF band, respectively. The feature classification between the nsrdb and afdb ECG signals was 96.53% accurate.
CONCLUSIONS: This study found that features of the ω of atrial fibrillation patients and healthy humans were associated with the frequency analysis of the ANS during parasympathetic activity. The feature ω is significant for different databases, and the classification between afdb and nsrdb was determined.

Matched MeSH terms: Heart Rate/physiology*
Borg CR-10 scale as a new approach to monitoring office exercise training

Shariat A, Cleland JA, Danaee M, Alizadeh R, Sangelaji B, Kargarfard M, et al.

Work, 2018;60(4):549-554.
PMID: 30103362 DOI: 10.3233/WOR-182762

BACKGROUND: There are many potential training exercises for office workers in an attempt to prevent musculoskeletal disorders. However, to date a suitable tool to monitor the perceived exertion of those exercises does not exist.
OBJECTIVE: The primary objective of this study was to examine the validity and reliability of the Borg CR-10 scale to monitor the perceived exertion of office exercise training.
METHODS: The study involved 105 staff members employed in a government office with an age range from 25 to 50 years. The Borg CR-10 scale was self-administered two times, with an interval of two weeks in order to evaluate the accuracy of the original findings with a retest. Face validity and content validity were also examined.
RESULTS: Reliability was found to be high for the Borg CR-10 scale (0.898). Additionally a high correlation between the Borg CR-10 scale and Visual Analog Scale (VAS) was identified (rs = 0.754, P

Matched MeSH terms: Heart Rate/physiology
Fulltext Effect of increasing heart rate on finger photoplethysmography fitness index (PPGF) in subjects with implanted cardiac pacemakers

Aminuddin A, Tan I, Butlin M, Avolio AP, Kiat H, Barin E, et al.

PLoS One, 2018;13(11):e0207301.
PMID: 30485318 DOI: 10.1371/journal.pone.0207301

Finger photoplethysmography (PPG) is a noninvasive method that measures blood volume changes in the finger. The PPG fitness index (PPGF) has been proposed as an index of vascular risk and vascular aging. The objectives of the study were to determine the effects of heart rate (HR) on the PPGF and to determine whether PPGF is influenced by blood pressure (BP) changes. Twenty subjects (78±8 years, 3 female) with permanent cardiac pacemakers or cardioverter defibrillators were prospectively recruited. HR was changed by pacing, in a random order from 60 to 100 bpm and in 10 bpm increments. At each paced HR, the PPGF was derived from a finger photoplethysmogram. Cardiac output (CO), stroke volume (SV) and total peripheral resistance (TPR) were derived from the finger arterial pressure waveform. Brachial blood pressure (BP) was measured by the oscillometric method. This study found that as HR was increased from 60 to 100 bpm, brachial diastolic BP, brachial mean BP and CO were significantly increased (p<0.01), whilst the PPGF and SV were significantly decreased (p<0.001). The effects of HR on the PPGF were influenced by BP, with a decreasing HR effect on the PPGF that resulted from a higher BP. In conclusion, HR was a significant confounder for PPGF and it must be taken into account in analyses of PPGF, when there are large changes or differences in the HR. The magnitude of this effect was BP dependent.

Matched MeSH terms: Heart Rate*

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links