Displaying publications 841 - 860 of 978 in total

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  1. Apprill PG, Ashton J, Guerrero J, Glas-Greenwalt P, Buja LM, Willerson JT
    Am Heart J, 1987 Apr;113(4):898-906.
    PMID: 3565240
    The potential use of ancrod, a purified isolate from the venom of the Malaysian pit viper, Agkistrodon rhodostoma, in decreasing the frequency of cyclic flow variations in severely stenosed canine coronary arteries and causing thrombolysis of an acute coronary thrombus induced by a copper coil was evaluated. Open-chest, anesthetized dogs were used. Ancrod was given intravenously (8 U/kg) over 1 hour and caused a significant reduction in the frequency of cyclic flow variations (5.8 +/- 0.7 to 3.6 +/- 0.8 cyclic flow variations per 30 minutes, p less than 0.05), whereas control animals failed to decrease the frequency of their cyclic flow variations over the same time period (5.3 +/- 0.3 to 5.0 +/- 0.4 cyclic flow variations per 30-minute period). Twenty-seven dogs had a coronary thrombus induced by a copper coil positioned directly in a major coronary artery; of these, four died of ventricular fibrillation prior to treatment, eight received an infusion of saline and showed no thrombolysis over 5 hours, and three died of ventricular fibrillation during the initial part of an intravenous infusion of ancrod. The remaining 12 dogs received ancrod intravenously (16 U/kg); six demonstrated lysis of the coronary thrombus (mean time to lysis, 65 +/- 20 minutes). The concentrations of ancrod used in these studies produced a severe decrease in systemic fibrinogen concentration and a significant decrease in the inhibitor of plasminogen activator levels. Thus, ancrod decreases the frequency of cyclic flow variations in stenosed canine coronary arteries and may cause coronary thrombolysis in approximately 50% of animals within 65 +/- 20 minutes of its intravenous administration.
    Matched MeSH terms: Heart Diseases/drug therapy
  2. Ahmad S, Valli H, Smyth R, Jiang AY, Jeevaratnam K, Matthews HR, et al.
    J Cell Physiol, 2019 Apr;234(4):3921-3932.
    PMID: 30146680 DOI: 10.1002/jcp.27183
    Peroxisome proliferator-activated receptor-γ coactivator-1 deficient (Pgc-1β-/- ) murine hearts model the increased, age-dependent, ventricular arrhythmic risks attributed to clinical conditions associated with mitochondrial energetic dysfunction. These were accompanied by compromised action potential (AP) upstroke rates and impaired conduction velocities potentially producing arrhythmic substrate. We tested a hypothesis implicating compromised Na+ current in these electrophysiological phenotypes by applying loose patch-clamp techniques in intact young and aged, wild-type (WT) and Pgc-1β-/- , ventricular cardiomyocyte preparations for the first time. This allowed conservation of their in vivo extracellular and intracellular conditions. Depolarising steps elicited typical voltage-dependent activating and inactivating inward Na+ currents with peak amplitudes increasing or decreasing with their respective activating or preceding inactivating voltage steps. Two-way analysis of variance associated Pgc-1β-/- genotype with independent reductions in maximum peak ventricular Na+ currents from -36.63 ± 2.14 (n = 20) and -35.43 ± 1.96 (n = 18; young and aged WT, respectively), to -29.06 ± 1.65 (n = 23) and -27.93 ± 1.63 (n = 20; young and aged Pgc-1β-/- , respectively) pA/μm2 (p 
    Matched MeSH terms: Heart Rate*
  3. Tumian NR, Wong M, Wong CL
    J Obstet Gynaecol Res, 2015 Jun;41(6):967-70.
    PMID: 25510540 DOI: 10.1111/jog.12648
    α°-thalassemia is a well-known cause of hydrops fetalis in South-East Asia and can be detected in utero. We report a very rare case of thyrotoxic cardiomyopathy associated with hyperplacentosis secondary to α°-thalassemia-associated hydrops fetalis. A 22-year-old primigravida with microcytic anemia presented at 27 weeks' gestation with pre-eclampsia, hyperthyroidism and cardiac failure. Serum β-human chorionic gonadotrophin was markedly elevated and abdominal ultrasound revealed severe hydropic features and enlarged placenta. Serum β-human chorionic gonadotrophin, cardiac function and thyroid function tests normalized after she delivered a macerated stillbirth. Histopathology of the placenta showed hyperplacentosis. Blood DNA analysis revealed that both patient and husband have the α°-thalassemia trait. This case illustrates a very atypical presentation of α°-thalassemia-associated hydrops fetalis and the importance of early prenatal diagnosis of α-thalassemia in women of relevant ethnic origin with microcytic anemia so that appropriate genetic counseling can be provided to reduce maternal morbidity and the incidence of hydrops fetalis.
    Matched MeSH terms: Heart Failure
  4. Madani G, Nekaris KA
    PMID: 25309586 DOI: 10.1186/1678-9199-20-43
    BACKGROUND: Asian slow lorises (Nycticebus spp.) are one of few known venomous mammals, yet until now only one published case report has documented the impact of their venomous bite on humans. We describe the reaction of a patient to the bite of a subadult Nycticebus kayan, which occurred in the Mulu District of Sarawak in 2012.

    FINDINGS: Within minutes of the bite, the patient experienced paraesthesia in the right side of the jaw, ear and right foot. By 40 minutes, swelling of the face was pronounced. The patient was admitted to Mulu National Park Health Clinic/Klinik Kesihatan Taman Mulu Tarikh, at which time he was experiencing: swollen mouth, chest pain, mild abdominal pain, nausea, numbness of the lips and mouth, shortness of breath, weakness, agitation and the sensation of pressure in the ears due to swelling. The blood pressure was 110/76, the heart ratio was 116 and oxygen saturation was 96%. The patient was treated intramuscularly with adrenaline (0.5 mL), followed by intravenous injection of hydrocortisone (400 mg) and then intravenous fluid therapy of normal saline (500 mg). By 8 h10 the next day, the patient's condition had significantly improved with no nausea, and with blood pressure and pulse rate stable.

    CONCLUSIONS: A handful of anecdotes further support the real danger that slow loris bites pose to humans. As the illegal pet trade is a major factor in the decline of these threatened species, we hope that by reporting on the danger of handling these animals it may help to reduce their desirability as a pet.
    Matched MeSH terms: Heart Rate
  5. Khalid T, Nesreen E, Ramadhan O
    Med J Malaysia, 2013 Dec;68(6):459-64.
    PMID: 24632913
    BACKGROUND: Postmenopausal hypertension is one of the leading causes of morbidity and mortality in women. Exercise training has been proved to decrease its risk factors and cardiovascular events. Aerobic exercise training stimulates endothelial nitric oxide release that acts as an antithrombotic and is cardiovascular protective. The effect of aerobic exercise training on postmenopausal hypertension is not fully elucidated.

    THE PURPOSE OF THE STUDY: to investigate the effects of moderate exercise training on nitric oxide levels in postmenopausal hypertension.

    METHODS: A prospective, randomized, controlled trial was conducted on 30 postmenopausal women involved in this study. The participants had at least one year's history of postmenopausal hypertension. Their ages ranged (40-50) years. Their body mass index ranged (30-36 Kg/m(2)). They were divided into two equal groups (treatment and control). Nitric oxide levels and blood pressure were measured in both groups in the initial examination at the beginning of the study, and at the end of the study. The treatment group received moderate aerobic exercise training. This ranged from 60-70% of maximum heart rate by walking on a treadmill at an average speed of 4km/hour for at least 20 minutes, three sessions a week, for 8 weeks.

    RESULTS: Body mass index, systolic and diastolic blood pressures were statistically significantly decreased. Nitric oxide levels were significantly increased in the treatment group. In this group the level of NO increased by 30.4% and systolic blood pressure decreased by 16.2%. Diastolic blood pressure decreased by 9.5% and body mass index decreased by 6%. In the control group the NO level increased by 8%. Systolic blood pressure decreased by 3% and diastolic blood pressure decreased by 3%.

    CONCLUSION: Exercise performed at moderate intensity for two months had obvious benefits in improving NO levels and controlling the hypertension in obese postmenopausal women.
    Matched MeSH terms: Heart Rate
  6. Nawi NM, Yahya A, Chen G, Bockari-Gevao SM, Maraseni TN
    J Agric Saf Health, 2012 Jan;18(1):45-56.
    PMID: 22458015
    A study was undertaken to evaluate the human energy consumption of various field operations involved in lowland rice cultivation in Malaysia. Based on recorded average heart rates, fertilizing was found to be the most strenuous operation, with an average heart rate of 138 beats min(-1). There were no significant differences in the average heart rates of the subjects among the individual tasks within the first plowing, second plowing, and harvesting operations, with the average heart rates for these three tasks being 116, 106, and 106 beats min(-1), respectively. The corresponding energy expenditures were 3.90, 3.43, and 3.35 kcal min(-1). Loading the seed into the blower tank and broadcasting the seed were the most critical tasks for the seed broadcasting operation, with average heart rates of 124 and 136 beats min(-1), respectively. The highest energy expenditure of 418.38 kcal ha(-1) was observed for seed broadcasting, and the lowest energy expenditure of 127.96 kcal ha(-1) was for second plowing. The total seasonal human energy expenditure for rice cultivation was estimated to be 5810.71 kcal ha(-1), 55.7% of which was spent on pesticide spraying. Although the sample size in this study was relatively small, the results indicated that human energy expenditure per unit area (kcal ha(-1)) was positively linked to the average heart rate of the subjects and negatively linked to the field capacity. Thus, mechanization of certain tasks could decrease worker physical effort and fatigue and increase production.
    Matched MeSH terms: Heart Rate
  7. Rahman ZA, Abdullah N, Singh R, Sosroseno W
    J Oral Sci, 2010 Mar;52(1):133-6.
    PMID: 20339244
    The aim of the present study was to assess the levels of salivary cortisol, tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) before, during and after acute exercise. Acute exercise was induced using a standard treadmill test with Bruce protocol in ten physically active male participants. Unstimulated saliva was collected before, during and after exercise. The levels of salivary cortisol and TNF-alpha were assessed by enzyme immunoassays. Salivary NO was determined by the Griess reagent. The results showed that both salivary cortisol and TNF-alpha increased and peaked at 14 min during exercise and then decreased. The levels of NO were increased up to 1 h after exercise and subsequently lowered after 24 h. The results of the present study suggest that acute exercise may induce high levels of salivary cortisol, TNF-alpha and NO.
    Matched MeSH terms: Heart Rate
  8. Taib NA, Hisham AN
    Asian J Surg, 2007 Jul;30(3):216-9.
    PMID: 17638642
    Direct tumour extension into the internal jugular veins (IJV) and right atrium in thyroid cancer is extremely uncommon. We report three cases of advanced thyroid cancer invading into the IJV and right atrium. All three patients had well-differentiated thyroid cancer and presented with typical clinical picture of the superior cava syndrome coupled with significant compressive symptoms. Two patients had obvious tumour thrombus extending to the superior vena cava (SVC) and right atrium, whilst in one patient, the thrombus extended to the SVC close to the edge of the right atrium. In all three patients, the intraluminal tumour thrombus was clinically palpable. Involvement of the IJV, SVC and right atrium was confirmed with computed tomography (CT) scan and echocardiography. The decision to extract the thrombus transcervically was made on the basis of the positive "ring sign", which is a thin rim of contrast surrounding the tumour thrombus documented on CT. All three patients underwent total thyroidectomy with segmental resection and ligation of the IJV. The tumour thrombus was successfully extracted transcervically. The histopathology report confirmed follicular carcinoma in all three patients. Two patients had radioiodine ablation therapy postoperatively, and were well 18 months after operation. One patient who had lung metastases documented on chest CT succumbed to the disease due to massive haemoptysis 3 weeks after operation.
    Matched MeSH terms: Heart Atria
  9. Subhani AR, Likun X, Saeed Malik A
    PMID: 23366661 DOI: 10.1109/EMBC.2012.6346700
    Cerebral activation and autonomic nervous system have importance in studies such as mental stress. The aim of this study is to analyze variations in EEG scalp potential which may influence autonomic activation of heart while playing video games. Ten healthy participants were recruited in this study. Electroencephalogram (EEG) and electrocardiogram (ECG) signals were measured simultaneously during playing video game and rest conditions. Sympathetic and parasympathetic innervations of heart were evaluated from heart rate variability (HRV), derived from the ECG. Scalp potential was measured by the EEG. The results showed a significant upsurge in the value theta Fz/alpha Pz (p<0.001) while playing game. The results also showed tachycardia while playing video game as compared to rest condition (p<0.005). Normalized low frequency power and ratio of low frequency/high frequency power were significantly increased while playing video game and normalized high frequency power sank during video games. Results showed synchronized activity of cerebellum and sympathetic and parasympathetic innervation of heart.
    Matched MeSH terms: Heart Rate
  10. Saat M, Sirisinghe RG, Singh R, Tochihara Y
    J Physiol Anthropol Appl Human Sci, 2005 Sep;24(5):541-9.
    PMID: 16237263
    This study investigates the effects of a short-term aerobic training program in a hot environment on thermoregulation, blood parameters, sweat secretion and composition in tropic-dwellers who have been exposed to passive heat. Sixteen healthy Malaysian-Malay male volunteers underwent heat acclimation (HA) by exercising on a bicycle ergometer at 60% of VO2max for 60 min each day in a hot environment (Ta: 31.1+/-0.1 degrees C, rh: 70.0+/-4.4%) for 14 days. All parameters mentioned above were recorded on Day 1 and at the end of HA (Day 16). On these two days, subjects rested for 10 min, then cycled at 60% of VO2max for 60 min and rested again for 20 min (recovery) in an improvised heat chamber. Rectal temperature (Tre), mean skin temperature (Tsk) heart rate (HR), ratings of perceived exertion (RPE), thermal sensation (TS), local sweat rate and percent dehydration were recorded during the test. Sweat concentration was analysed for sodium [Na+]sweat and potassium. Blood samples were analysed for biochemical changes, electrolytes and hematologic indices. Urine samples were collected before and after each test and analysed for electrolytes.After the period of acclimation the percent dehydration during exercise significantly increased from 1.77+/-0.09% (Day 1) to 2.14+/-0.07% (Day 16). Resting levels of hemoglobin, hematocrit and red blood cells decreased significantly while [Na+]sweat increased significantly. For Tre and Tsk there were no differences at rest. Tre, HR, RPE, TS, plasma lactate concentration, hemoglobin and hematocrit at the 40th min of exercise were significantly lower after the period of acclimation but mean corpuscular hemoglobin and serum osmolality were significantly higher while no difference was seen in [Na+]sweat and Tsk. It can be concluded that tropic-dwelling subjects, although exposed to prolonged passive heat exposure, were not fully heat acclimatized. To achieve further HA, they should gradually expose themselves to exercise-heat stress in a hot environment.
    Matched MeSH terms: Heart Rate
  11. Hassan Y, Awaisu A, Aziz NA, Ismail O
    Pharm World Sci, 2005 Feb;27(1):16-9.
    PMID: 15861930
    Phenytoin has been reported to have major interactions with warfarin. Phenytoin induces warfarin's metabolism. However, there are many case reports which provide conflicting conclusions. Here, we report a case of a 65-year-old man with mechanical heart valve on chronic warfarin therapy who experienced persistent fluctuations of INR and bleeding secondary to probable warfarin-phenytoin interactions. The patient's anticoagulation clinic visits prior to hospitalization were thoroughly evaluated and we continued to follow-up the case for 3 months post-hospitalization. The reported interaction could be reasonably explained from the chronology of events and the pattern of INR fluctuations whenever phenytoin was either added or discontinued from his drug regimen.
    Matched MeSH terms: Heart Valve Prosthesis
  12. Kwon WK, Sung TY, Yu GY, Sidik H, Kang WS, Lee Y, et al.
    J Anesth, 2016 Apr;30(2):223-31.
    PMID: 26577248 DOI: 10.1007/s00540-015-2094-9
    BACKGROUND: The direct impact of sevoflurane on intraoperative left ventricular (LV) systolic performance during cardiac surgery has not been fully elucidated. Peak systolic tissue Doppler velocities of the lateral mitral annulus (S') have been used to evaluate LV systolic long-axis performance. We hypothesized that incremental sevoflurane concentration (1.0-3.0 inspired-vol%) would dose-dependently reduce S' in patients undergoing cardiac surgery due to mitral or aortic insufficiency.

    METHODS: In 20 patients undergoing cardiac surgery in sevoflurane-remifentanil anesthesia, we analyzed intraoperative S' values which were determined after 10 min exposure to sevoflurane at 1.0, 2.0, and 3.0 inspired-vol% (T1, T2, and T3, respectively) with a fixed remifentanil dose (1.0 μg/kg/min) using transesophageal echocardiography.

    RESULTS: Linear mixed-effect modeling demonstrated dose-dependent declines in S' according to the end-tidal sevoflurane concentration increments (C(ET)-sevoflurane, p < 0.001): the mean value of S' reduction for each 1.0 vol%-increment of C(ET)-sevoflurane was 1.7 cm/s (95 % confidence interval 1.4-2.1 cm/s). Medians of S' at T1, T2, and T3 (9.6, 8.9, and 7.5 cm/s, respectively) also exhibited significant declines (by 6.6, 15.6, and 21.2 % for T1 vs. T2, T2 vs. T3, and T1 vs. T3, p < 0.001, =0.002, and <0.001 in Friedman pairwise comparisons, respectively).

    CONCLUSIONS: Administering sevoflurane as a part of a sevoflurane-remifentanil anesthesia regimen appears to dose-dependently reduce S', indicating LV systolic performance, in patients undergoing cardiac surgery. Further studies may be required to evaluate the clinical implications of these findings.

    Matched MeSH terms: Heart Ventricles
  13. Sandeep HV, Sarat KS, Ng LT
    Med J Malaysia, 2016 02;71(1):39-40.
    PMID: 27130746
    Extra-adrenal /retroperitoneal paraganglioma is a rare cause of hypertension in young with increased incidence of metastasis as compared to adrenal pheochromocytoma. We present a case of a young female with history of headache, nausea/vomiting, palpitations, uncontrolled hypertension, heat intolerance and diaphoresis. The 24-hour urine catecholamine levels were elevated. Clinical diagnosis of pheochromocytoma was made and further evaluation with Computed Tomography (CT) scan of the adrenals revealed extradrenal para-aortic retroperitoneal mass in keeping with paraganglioma. Gallium-68 DOTATE positron emission tomography-CT scan (PET-CT) confirmed the diagnosis without evidence of metastatic foci.
    Matched MeSH terms: Heart Rate
  14. Dabinett JA, Reid K, James N
    Int J Sport Nutr Exerc Metab, 2001 Sep;11(3):334-48.
    PMID: 11591883
    The purpose of the present study was to develop a hydration strategy for use by female English field hockey players at the 1998 Commonwealth Games in Malaysia. An additional aim was to initiate the process of acclimation. Fifteen elite players, mean age (+/-SEM) 24.1 +/- 1.19 years, height 1.67 +/- 0.01 m, and body mass 62.8 +/- 1.76 kg, took part in a 5-day training camp immediately prior to departure for the Games. In order to develop the hydration strategy, training took place under similar environmental conditions to those to be experienced in Malaysia (i.e., 32 degrees C, 80% humidity). Acclimation training consisted of 30-50 min of either continuous, low intensity cycling or high intensity intermittent cycling, which more closely replicated the pattern of activity in field hockey. Body mass measures taken each morning, and pre and post training, together with urine color measures, were used to assess hydration status. Pre-loading with up to 1 L of a 3% carbohydrate-electrolyte solution or water immediately prior to acclimation training, as well as regular drinks throughout, ensured that players avoided significant dehydration, with percent body mass changes ranging from -0.34% to +4.24% post training. Furthermore, the protocol used was sufficient to initiate the process of acclimation as demonstrated by a significant reduction in exercising heart rate and core temperature at all time points by days 4 and 5. In conclusion, although labor intensive and time consuming, the camp was successful in developing a hydration strategy that players were able to utilize once at the Games.
    Matched MeSH terms: Heart Rate
  15. Fu YC, Chi CS, Jan SL, Wang TM, Chen PY, Chang Y, et al.
    Pediatr Pulmonol, 2003 Apr;35(4):263-8.
    PMID: 12629622
    Epidemics of enterovirus 71 infections caused the rapid death of many children in Malaysia in 1997 and in Taiwan in 1998. Pulmonary edema occurred in most of the fatal cases and was considered to be neurogenic. The role of the heart was rarely investigated before. Between January 1998-January 2001, 34 consecutive patients who were admitted to the intensive care unit due to enterovirus infection were studied prospectively. Patients were divided into two groups: group I with pulmonary edema, and group II without pulmonary edema. Comparisons were made between the two groups based upon demographic, neurological, and cardiovascular manifestations. Group I consisted of 11 patients (5 boys, 6 girls; mean age, 22.8 months), and group II of 23 patients (12 boys, 11 girls; mean age, 28.8 months). There were no significant differences between the two groups in comparing sex, age, body weight, neurological severity, intracranial pressure, cell count, protein and glucose levels in cerebral spinal fluid, and blood pressure. All group I patients had left ventricular dysfunction, and their ejection fractions were significantly lower than those of patients in group II (37 +/- 11% vs. 75 +/- 6%, P < 0.001). Group I heart rates were higher than those of group II (175 +/- 24 vs. 137 +/- 25, P < 0.001). In group I, 9 patients who received conventional treatment died, and the only two survivors received left ventricular assist devices. In conclusion, the pulmonary edema of fulminant enterovirus 71 infection is associated with left ventricular failure. Left ventricular function is the major determinant of outcome. Early recognition of heart failure and aggressive cardiac intervention are life-saving. Pediatr Pulmonol. 2003; 35:263-268.
    Matched MeSH terms: Heart-Assist Devices
  16. Duncan MT, Horvath SM
    PMID: 3396569
    Young sedentary adult males of Malay, Indian, and Chinese origin who had established continuous residence in tropical Malaysia and presumed to be naturally acclimatized to heat, were studied to evaluate their physiological responses to a standard heat stress test. The Malay and Indian races have evolved in hot and humid geographical zones, whereas the Chinese originated from a temperate area. Subjects exercised at 50% VO2max alternating 18 minutes walking and 2 min rest during a 2-h exposure to an ambient of 34.9 degrees C dry bulb and 32.1 degrees C wet bulb. Heart rates, core and skin temperatures, sweat rates, and oxygen uptakes were measured during the heat exposure. The subjects of Malay origin exhibited the least circulatory stress of the three ethnic groups. The data obtained on these long-term residents of a hot-wet climate and who were considered acclimatized to this environment were compared to experimental data obtained by other investigators and other ethnic groups.
    Matched MeSH terms: Heart Rate
  17. Duncan M
    Q J Exp Physiol Cogn Med Sci, 1972 Jul;57(3):247-56.
    PMID: 4483129
    Matched MeSH terms: Heart Rate
  18. Urban John Arnold D’Souza, Vinod Kumar S., Nagesh Chodankar
    MyJurnal
    Introduction: Regular physical activity and VO2 max are correlated directly. Physical anthropometry physical ac-tivity, lung function and cardiac parameters such as systolic, diastolic blood pressure and resting heart rate are the important baseline parameters in relation to the a healthy life. In this study, a comprehensive determination of these parameters were planned among the common ethnicities of Sabah. This study in turn aims at making the sedentary people to make physically active and implicate a possible relationship between cardio-respiratory parameters with the physical activity levels. Methods: A total of 385 young adult Sabah, Malaysia college students with n=148 males and n= 237 females were randomly selected from the different colleges in Kota Kinabalu. Ethical clearance was received from Faculty of Medicine & Health Sciences UMS, and the participants were briefed on the procedures with their voluntary consent. IPAQ-Score/Met-Min/Week, BMI, resting heart rate, blood pressure, lung function parameters – forced vital capacity, peak expiratory flow rate etc were estimated by standard techniques. Data was analyzed, a regression analysis and ANOVA was performed to assess the relationship between independent and dependent variables. Results: Physical activity level has a significant correlation with the dependent variables of this study. VO2max is significantly and inversely related to body weight, BMI, blood pressure and pulse rate, whereas physical activity level is directly correlated. A weak positive correlation for VO2 max with lung function parameters.Conclusion: Physical activity, VO2 max and cardio-respiratory parameters; interdependently correlated and regular activity contributed to the rate of oxygen consumption.
    Matched MeSH terms: Heart Rate
  19. Chung CH, Bretherton B, Zainalabidin S, Deuchars SA, Deuchars J, Mahadi MK
    Front Neurosci, 2020;14:906.
    PMID: 33013299 DOI: 10.3389/fnins.2020.00906
    Background: Myocardial infarction (MI) reperfusion therapy causes paradoxical cardiac complications. Following restoration of blood flow to infarcted regions, a multitude of inflammatory cells are recruited to the site of injury for tissue repair. Continual progression of cardiac inflammatory responses does, however, lead to adverse cardiac remodeling, inevitably causing heart failure.

    Main Body: Increasing evidence of the cardioprotective effects of both invasive and non-invasive vagal nerve stimulation (VNS) suggests that these may be feasible methods to treat myocardial ischemia/reperfusion injury via anti-inflammatory regulation. The mechanisms through which auricular VNS controls inflammation are yet to be explored. In this review, we discuss the potential of autonomic nervous system modulation, particularly via the parasympathetic branch, in ameliorating MI. Novel insights are provided about the activation of the cholinergic anti-inflammatory pathway on cardiac macrophages. Acetylcholine binding to the α7 nicotinic acetylcholine receptor (α7nAChR) expressed on macrophages polarizes the pro-inflammatory into anti-inflammatory subtypes. Activation of the α7nAChR stimulates the signal transducer and activator of transcription 3 (STAT3) signaling pathway. This inhibits the secretion of pro-inflammatory cytokines, limiting ischemic injury in the myocardium and initiating efficient reparative mechanisms. We highlight recent developments in the controversial auricular vagal neuro-circuitry and how they may relate to activation of the cholinergic anti-inflammatory pathway.

    Conclusion: Emerging published data suggest that auricular VNS is an inexpensive healthcare modality, mediating the dynamic balance between pro- and anti-inflammatory responses in cardiac macrophages and ameliorating cardiac ischemia/reperfusion injury.

    Matched MeSH terms: Heart Failure
  20. Willmott AGB, Hayes M, James CA, Gibson OR, Maxwell NS
    Temperature (Austin), 2019 Sep 19;7(2):178-190.
    PMID: 33015245 DOI: 10.1080/23328940.2019.1664370
    Athletes exercising in heat stress experience increased perceived fatigue acutely, however it is unknown whether heat acclimation (HA) reduces the magnitude of this perceptual response and whether different HA protocols influence the response. This study investigated sensations of fatigue following; acute exercise-heat stress; short- (5-sessions) and medium-term (10-sessions) HA; and between once- (ODHA) and twice-daily HA (TDHA) protocols. Twenty male participants (peak oxygen uptake: 3.75 ± 0.47 L·min-1) completed 10 sessions (60-min cycling at ~2 W·kg-1, 45°C/20% relative humidity) of ODHA (n = 10) or non-consecutive TDHA (n = 10). Sensations of fatigue (General, Physical, Emotional, Mental, Vigor and Total Fatigue) were assessed using the multi-dimensional fatigue scale inventory-short form pre and post session 1, 5 and 10. Heat adaptation was induced following ODHA and TDHA, with reductions in resting rectal temperature and heart rate, and increased plasma volume and sweat rate (P Heart rate; IL-6: Interleukin-6; MFS-SF: Multi-dimensional fatigue symptom inventory-short form (MFSI-SF); MTHA: Medium-term heat acclimation; Na+: Sodium; ODHA: Once daily heat acclimation; PV: Plasma volume; RH: Relative humidity; RPE: Rating of perceived exertion; SD: Standard deviation; SE: Standard error of the slope coefficient or intercept; SEE : Standard error of the estimate for the regression equation; STHA: Short-term heat acclimation; TDHA: Twice daily heat acclimation; TC: Thermal Comfort; Tre: Rectal temperature; TSS: Thermal sensation; V̇O2peak: Peak oxygen uptake; WBSL: whole-body sweat loss.
    Matched MeSH terms: Heart Rate
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