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BACKGROUND: The elevated blood pressure (BP) and lower cardiac autonomic modulation (CAM) are associated with higher morbidity mortality risk among older adults. Although exercise is an important intervention for cardiovascular promotion, it is unclear whether combat sports training could benefit cardiovascular outcomes as much as autonomic in this population. This study compared the effects of 12 weeks of Muay Thai (MT) training against functional training (FT) on CAM and hemodynamic parameters in older adults. METHODS: The sample consisted of 50 older adults (41 women; 66.0 ± 5.3 years old), who were equaly randomized into FT (n = 25) and MT (n = 25) intervention groups. CAM was measured by 30-min rest heart rate variability. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and resting heart rate (RHR) were measured using an automatic oscillometric device. Pulse pressure (PP) and the double product (DP) were also calculated. The interventions were carried out three times a week, with 60-min length per session, during 12 consecutive weeks. The intensity of the interventions was measured using the subjective perception of exertion scale and by accelerometer. Two-factor repeated measures analysis of covariance was used for groups comparison, considering intervention group and body mass as factors. The 95% confidence interval of the difference (95%CIdif) was also calculated and the effect size was measured using partial eta squared (η2p). RESULTS: CAM indices did not show significant changes across moments and intervention groups. In hemodynamic parameters, only in DBP was there an effect of the moment (F1,39 = 8.206; P = 0.007; η2p = 0.174, large) and interaction effect between group*moment (F1,39 = 7.950; P = 0.008; η2p = 0.169, large). Specifically, the MT group at the post-training moment showed lower DBP (P = 0.010; 95%CIdif = -13.3; -1.89) in relation to the FT group. Furthermore, the MT group showed a decrease in DBP during training (P = 0.002; 95%CIdif = -10.3; -2.6). Also, an increase in training intensity was also found over the 12 weeks in FT, with no difference between the groups. CONCLUSION: After 12 weeks of MT practice there was a reduction in DBP compared to FT in older adults. TRIAL REGISTRATION: NCT03919968 Registration date: 01/02/2019.
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Sistema Nervioso Autónomo , Presión Sanguínea , Frecuencia Cardíaca , Hemodinámica , Humanos , Femenino , Masculino , Anciano , Sistema Nervioso Autónomo/fisiopatología , Factores de Tiempo , Persona de Mediana Edad , Resultado del Tratamiento , Factores de Edad , Tailandia , Terapia por Ejercicio/métodos , Corazón/inervación , Pueblos del Sudeste AsiáticoRESUMEN
INTRODUCTION: Cardiac autonomic system functioning may be altered by obesity leading to cardiovascular diseases and associated complications. Military police officers are exposed to traditional and occupational risk factors for the development of CVD, however data on the cardiovascular health in this population is still scarce. AIM: In this cross-sectional study, we investigated the impact of obesity on cardiac autonomic modulation and the hemodynamic profile in male active-duty military police officers. METHODS: The body composition of the volunteers was assessed by octapolar electrical bioimpedance. Participants were classified as non-obese or obese in accordance with their body fat, with further subgroups as physically active obese or insufficiently active obese using International Physical Activity Questionnaire (IPAQ). Cardiac autonomic modulation was assessed by heart rate variability and the automatic oscillometric method allowed us to assess hemodynamic features. RESULTS: 102 military police officers from the state of São Paulo participated in the study. Cardiac autonomic modulation revealed significant impairment in time and frequency domains and non-linear methods in the obese group compared to the non-obese (p < 0.05). A higher physical activity level did not alter these results in the obese group. However, no significant differences in the hemodynamic profile were observed between groups (p > 0.05). CONCLUSION: These findings suggest a negative association between obesity and cardiac autonomic modulation in military police officers, unaffected by increased physical activity.
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Sistema Nervioso Autónomo , Frecuencia Cardíaca , Obesidad , Policia , Humanos , Masculino , Estudios Transversales , Sistema Nervioso Autónomo/fisiopatología , Adulto , Obesidad/fisiopatología , Obesidad/diagnóstico , Obesidad/epidemiología , Brasil/epidemiología , Corazón/inervación , Corazón/fisiopatología , Salud Laboral , Hemodinámica , Salud Militar , Adiposidad , Medición de Riesgo , Personal Militar , Adulto JovenRESUMEN
The dorsal motor nucleus of the vagus (DMV) contains parasympathetic motoneurons that project to the heart and lungs. These motoneurons control ventricular excitability/contractility and airways secretions/blood flow, respectively. However, their electrophysiological properties, morphology and synaptic input activity remain unknown. One important ionic current described in DMV motoneurons controlling their electrophysiological behaviour is the A-type mediated by voltage-dependent K+ (Kv) channels. Thus, we compared the electrophysiological properties, synaptic activity, morphology, A-type current density, and single cell expression of Kv subunits, that contribute to macroscopic A-type currents, between DMV motoneurons projecting to either the heart or lungs of adult male rats. Using retrograde labelling, we visualized distinct DMV motoneurons projecting to the heart or lungs in acutely prepared medullary slices. Subsequently, whole cell recordings, morphological reconstruction and single motoneuron qRT-PCR studies were performed. DMV pulmonary motoneurons were more depolarized, electrically excitable, presented higher membrane resistance, broader action potentials and received greater excitatory synaptic inputs compared to cardiac DMV motoneurons. These differences were in part due to highly branched dendritic complexity and lower magnitude of A-type K+ currents. By evaluating expression of channels that mediate A-type currents from single motoneurons, we demonstrated a lower level of Kv4.2 in pulmonary versus cardiac motoneurons, whereas Kv4.3 and Kv1.4 levels were similar. Thus, with the distinct electrical, morphological, and molecular properties of DMV cardiac and pulmonary motoneurons, we surmise that these cells offer a new vista of opportunities for genetic manipulation providing improvement of parasympathetic function in cardiorespiratory diseases such heart failure and asthma.
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Corazón , Pulmón , Neuronas Motoras , Nervio Vago , Animales , Neuronas Motoras/fisiología , Masculino , Corazón/fisiología , Corazón/inervación , Pulmón/fisiología , Pulmón/inervación , Nervio Vago/fisiología , Bulbo Raquídeo/fisiología , Bulbo Raquídeo/citología , Bulbo Raquídeo/metabolismo , Potenciales de Acción/fisiología , Ratas Sprague-Dawley , Ratas , Técnicas de Placa-ClampRESUMEN
PURPOSE OF REVIEW: More than a century since its discovery, the pathogenesis of Chagas heart disease (CHD) remains incompletely understood. The role of derangements in the autonomic control of the heart in triggering malignant arrhythmia before the appearance of contractile ventricular impairment was reviewed. RECENT FINDINGS: Although previous investigations had demonstrated the anatomical and functional consequences of parasympathetic dysautonomia upon the heart rate control, only recently, coronary microvascular disturbances and sympathetic denervation at the ventricular level have been reported in patients and experimental models of CHD, exploring with nuclear medicine methods their impact on the progression of myocardial dysfunction and cardiac arrhythmias. More important than parasympathetic impaired sinus node regulation, recent evidence indicates that myocardial sympathetic denervation associated with coronary microvascular derangements is causally related to myocardial injury and arrhythmia in CHD. Additionally, 123I-MIBG imaging is a promising tool for risk stratification of progression of ventricular dysfunction and sudden death.
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Cardiomiopatía Chagásica , Simpatectomía , Humanos , Simpatectomía/métodos , Cardiomiopatía Chagásica/fisiopatología , Cardiomiopatía Chagásica/cirugía , Cardiomiopatía Chagásica/complicaciones , Arritmias Cardíacas/etiología , Arritmias Cardíacas/fisiopatología , Corazón/inervación , Corazón/diagnóstico por imagen , 3-Yodobencilguanidina , Sistema Nervioso Simpático/fisiopatologíaRESUMEN
Objective.To conduct a systematic review of the possible effects of passive heating protocols on cardiovascular autonomic control in healthy individuals.Approach.The studies were obtained from MEDLINE (PubMed), LILACS (BVS), EUROPE PMC (PMC), and SCOPUS databases, simultaneously. Studies were considered eligible if they employed passive heating protocols and investigated cardiovascular autonomic control by spontaneous methods, such as heart rate variability (HRV), systolic blood pressure variability (SBPV), and baroreflex sensitivity (BRS), in healthy adults. The revised Cochrane risk-of-bias tool (RoB-2) was used to assess the risk of bias in each study.Main results.Twenty-seven studies were included in the qualitative synthesis. Whole-body heating protocols caused a reduction in cardiac vagal modulation in 14 studies, and two studies reported both increased sympathetic modulation and vagal withdrawal. Contrariwise, local-heating protocols and sauna bathing seem to increase cardiac vagal modulation. A reduction of BRS was reported in most of the studies that used whole-body heating protocols. However, heating effects on BRS remain controversial due to methodological differences among baroreflex analysis and heating protocols.Significance.Whole-body heat stress may increase sympathetic and reduce vagal modulation to the heart in healthy adults. On the other hand, local-heating therapy and sauna bathing seem to increase cardiac vagal modulation, opposing sympathetic modulation. Nonetheless, further studies should investigate acute and chronic effects of thermal therapy on cardiovascular autonomic control.
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Sistema Nervioso Autónomo , Sistema Cardiovascular , Hipertermia Inducida , Adulto , Humanos , Sistema Nervioso Autónomo/fisiología , Sistema Nervioso Autónomo/fisiopatología , Barorreflejo/fisiología , Presión Sanguínea/fisiología , Sistema Cardiovascular/inervación , Sistema Cardiovascular/fisiopatología , Corazón/inervación , Corazón/fisiología , Frecuencia Cardíaca/fisiología , Calor/efectos adversos , Hipertermia Inducida/efectos adversos , Hipertermia Inducida/métodosRESUMEN
OBJECTIVES: This crossover study design aimed to assess hemodynamic, cardiac autonomic, and vascular responses to high-intensity interval (HIIE) vs moderate-intensity continuous exercise (MICE) in older individuals with hypertension. METHODS: Twenty (67 ± 7 y) older individuals with hypertension were randomly assigned to perform HIIE, MICE, or control (CON) sessions in the heated swimming pool (30-32°C). Blood pressure (BP), arterial stiffness, endothelial reactivity, and heart rate variability (HRV) were measured pre, post, and 45 min (recovery) after each intervention followed by 24-h ambulatory BP and HRV. RESULTS: One single aerobic exercise session was not effective to provoke post-exercise hypotension and vascular improvements. HIIE was superior to MICE and CON to increasing parasympathetic modulation at post and recovery. Exercise sessions showed to disturb the autonomic system at nighttime compared to CON. CONCLUSIONS: These results may have important implications in water-based therapy and the elderly with hypertension.
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Terapia Acuática , Entrenamiento de Intervalos de Alta Intensidad , Hipertensión , Anciano , Terapia Acuática/métodos , Sistema Nervioso Autónomo/fisiopatología , Presión Sanguínea/fisiología , Vasos Sanguíneos/fisiopatología , Estudios Cruzados , Ejercicio Físico/fisiología , Corazón/inervación , Corazón/fisiopatología , Frecuencia Cardíaca/fisiología , Calefacción , Hemodinámica/fisiología , Entrenamiento de Intervalos de Alta Intensidad/métodos , Humanos , Hipertensión/fisiopatología , Hipertensión/terapia , Persona de Mediana EdadRESUMEN
BACKGROUND: Advances in diagnosis and treatment of cancer has improved survival but resulted in increased cardiotoxic effects. The decrease in left ventricular ejection fraction (EF), one of the pillars of diagnosis of cardiotoxicity, seems to be a late process in the evolution of the disease, so 123I-metaiodobenzylguanidine (MIBG) cardiac imaging has been proposed to detect early cardiac impairment. The aim of this systematic review was to evaluate the performance of MIBG cardiac scan in this scenario. METHODS AND RESULTS: A systematic search was conducted in five international databases comparing MIBG parameters with EF for evaluation of cardiotoxicity. Twelve studies were included and separated in three groups. First, studies evaluating patients with established cardiotoxicity, in which EF was reduced and MIBG parameters were abnormal. Second, studies analyzing patients during or after treatment compared to controls, with MIBG parameters significantly different between groups in most studies, even when EF remained normal. Finally, studies analyzing anthracycline (ATC) dose-related changes, with alteration in MIBG parameters occurring even when EF was preserved. CONCLUSION: Although studies had high methodological variability, cardiac sympathetic innervation imaging seems to be a promising tool for assessing early cardiotoxicity. Further studies are needed to analyze its diagnostic value in this scenario.
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3-Yodobencilguanidina , Cardiotoxicidad , Antraciclinas/efectos adversos , Cardiotoxicidad/diagnóstico por imagen , Corazón/inervación , Humanos , Volumen Sistólico , Función Ventricular IzquierdaRESUMEN
Objective: The present study sought to expand upon prior investigations of the relationship between the post-exercise heart rate recovery (HRR) and the cardiac autonomic responsiveness after orthostatic stress test.Method: HRR at the 1st, 3rd, and 5th min after maximal exercise test were correlated with relative change (Δ%) of time-domain (CV, pNN50, and rMSSD) and frequency-domain (TP, LF, HF, and LF/HF ratio) indices of heart rate variability (HRV) after active orthostatic test in 46 healthy men. Statistical analysis employed non-parametric tests with a p-value set at 5%.Results: HRR at 1st min correlated with Δ%pNN50 (rs:0.36 - p = .02). In the 3rd and 5th min, these measures correlated with Δ%pNN50, Δ%rMSSD, Δ%CV, Δ%TP, and Δ%HF indices (rs:0.33, 0.59 - p ≤ .05). Coefficient of HRR at the 1st min correlated with Δ%pNN50, Δ%rMSSD, and Δ%HF (rs:0.28, 0.45 - p ≤ .05). The 3rd and 5th min showed correlation with Δ%pNN50, Δ%rMSSD, Δ%HF, Δ%CV, and Δ%TP (rs:0.37, 0.64 - p ≤ .05). No correlation was found with indices combined sympathetic-parasympathetic modulation and HRR. After the sample was divided into high and low parasympathetic responsiveness subgroups after the orthostatic test, faster HRR was associated with the degree of parasympathetic responsiveness (reduction) following postural change (p ≤ .05).Conclusion: HRR throughout the 1st to 5th min is positively correlated with parasympathetic responsiveness and overall cardiac autonomic modulation of HRV after the orthostatic stress test, and faster HRR is positively correlated with the relative degree of parasympathetic responsiveness after the active postural change at rest in healthy men.
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Sistema Nervioso Autónomo , Prueba de Esfuerzo , Frecuencia Cardíaca , Corazón , Recuperación de la Función , Sistema Nervioso Autónomo/fisiología , Corazón/inervación , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Recuperación de la Función/fisiología , Factores de TiempoRESUMEN
Doxorubicin (DOX) is an anticancer chemotherapy drug that is widely used in clinical practice. It is well documented that DOX impairs baroreflex responsiveness and left ventricular function and enhances sympathetic activity, cardiac sympathetic afferent reflexes and oxidative stress, which contribute to hemodynamic deterioration. Because resistance training (RT)-induced cardioprotection has been observed in other animal models, the objective of this study was to assess the effects of RT during DOX treatment on hemodynamics, arterial baroreflex, cardiac autonomic tone, left ventricular function and oxidative stress in rats with DOX-induced cardiotoxicity. Male Wistar rats were submitted to a RT protocol (3 sets of 10 repetitions, 40% of one-repetition maximum (1RM) of intensity, 3 times per week, for 8 weeks). The rats were separated into 3 groups: sedentary control, DOX sedentary (2.5 mg/kg of DOX intraperitoneal injection, once a week, for 6 weeks) and DOX + RT. After training or time control, the animals were anesthetized and 2 catheters were implanted for hemodynamic, arterial baroreflex and cardiac autonomic tone. Another group of animals was used to evaluate left ventricular function. We found that RT in DOX-treated rats decreased diastolic arterial pressure, heart rate, sympathetic tone and oxidative stress. In addition, RT increased arterial baroreflex sensitivity, vagal tone and left ventricular developed pressure in rats with DOX-induced cardiotoxicity. In summary, RT is a useful non-pharmacological strategy to attenuate DOX-induced cardiotoxicity.
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Sistema Nervioso Autónomo/fisiopatología , Cardiopatías/terapia , Corazón/inervación , Condicionamiento Físico Animal , Entrenamiento de Fuerza , Animales , Barorreflejo/efectos de los fármacos , Cardiotoxicidad , Modelos Animales de Enfermedad , Doxorrubicina , Cardiopatías/inducido químicamente , Cardiopatías/metabolismo , Cardiopatías/fisiopatología , Hemodinámica/efectos de los fármacos , Masculino , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas Wistar , Función Ventricular Izquierda/efectos de los fármacosRESUMEN
This study aimed to analyze the relationship between cardiac autonomic modulation (CAM) and cardiovascular parameters (blood pressure and resting heart rate) in a sample of 256 adults, grouped by body mass index and sufficient moderate-to-vigorous physical activity (≥150 min/week). The sample showed different cardiovascular parameters and CAM according to body mass index, but not according to physical activity. Adults who are overweight and physically active presented higher relationship between CAM and blood pressure than those who are insufficiently active, similarly to normal weight groups. Recommended levels of physical activity may play an important role in the relationship of HRV with cardiovascular parameters in overweight adults, regardless of sex, age, socioeconomic level, and central fat. Trial registration: Registered at ClinicalTrials.gov (NCT03986879). Graphical abstract.
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Sistema Nervioso Autónomo/fisiopatología , Índice de Masa Corporal , Ejercicio Físico , Frecuencia Cardíaca , Corazón/inervación , Sobrepeso/fisiopatología , Adolescente , Adulto , Presión Sanguínea , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sobrepeso/diagnóstico , Sobrepeso/epidemiología , Prevalencia , Conducta Sedentaria , Adulto JovenRESUMEN
Paraquat (PQT) herbicide is widely used in agricultural practices despite being highly toxic to humans. It has been proposed that PQT exposure may promote cardiorespiratory impairment. However, the physiological mechanisms involved in cardiorespiratory dysfunction following PQT exposure are poorly known. We aimed to determine the effects of PQT on ventilatory chemoreflex control, cardiac autonomic control, and cardiac function in rats. Male Sprague-Dawley rats received two injections/week of PQT (5 mg·kg-1 ip) for 4 wk. Cardiac function was assessed through echocardiography and pressure-volume loops. Ventilatory function was evaluated using whole body plethysmography. Autonomic control was indirectly evaluated by heart rate variability (HRV). Cardiac electrophysiology (EKG) and exercise capacity were also measured. Four weeks of PQT administration markedly enlarged the heart as evidenced by increases in ventricular volumes and induced cardiac diastolic dysfunction. Indeed, end-diastolic pressure was significantly higher in PQT rats compared with control (2.42 ± 0.90 vs. 4.01 ± 0.92 mmHg, PQT vs. control, P < 0.05). In addition, PQT significantly reduced both the hypercapnic and hypoxic ventilatory chemoreflex response and induced irregular breathing. Also, PQT induced autonomic imbalance and reductions in the amplitude of EKG waves. Finally, PQT administration impaired exercise capacity in rats as evidenced by a â¼2-fold decrease in times-to-fatigue compared with control rats. Our results showed that 4 wk of PQT treatment induces cardiorespiratory dysfunction in rats and suggests that repetitive exposure to PQT may induce harmful mid/long-term cardiovascular, respiratory, and cardiac consequences.NEW & NOREWORTHY Paraquat herbicide is still employed in agricultural practices in several countries. Here, we showed for the first time that 1 mo paraquat administration results in cardiac adverse remodeling, blunts ventilatory chemoreflex drive, and promotes irregular breathing at rest in previously healthy rats. In addition, paraquat exposure induced cardiac autonomic imbalance and cardiac electrophysiology alterations. Lastly, cardiac diastolic dysfunction was overt in rats following 1 mo of paraquat treatment.
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Arritmias Cardíacas/inducido químicamente , Sistema Nervioso Autónomo/efectos de los fármacos , Células Quimiorreceptoras/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Corazón/inervación , Herbicidas/toxicidad , Hipertrofia Ventricular Izquierda/inducido químicamente , Pulmón/inervación , Paraquat/toxicidad , Ventilación Pulmonar/efectos de los fármacos , Reflejo/efectos de los fármacos , Animales , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatología , Sistema Nervioso Autónomo/fisiopatología , Células Quimiorreceptoras/metabolismo , Tolerancia al Ejercicio/efectos de los fármacos , Hipertrofia Ventricular Izquierda/metabolismo , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Ratas Sprague-Dawley , Función Ventricular Izquierda/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacosRESUMEN
The central autonomic network, which is connected to the limbic system structures including the amygdala (AMY) and anterior hippocampus (aHIP), regulates the sympathetic and parasympathetic modulation of visceromotor, neuroendocrine, pain, and behavior manifestations during stress responses. Heart rate variability (HRV) is useful to estimate the cardiac autonomic tone. The levels of phosphorylation on the Ser831 and Ser845 sites of the GluA1 subunit of the AMPAr (P-GluA1-Ser845 and P-GluA1-Ser831) are useful markers of synaptic plasticity. The relation between synaptic plasticity in the human limbic system structures and autonomic regulation in humans is unknown. This study investigated the association between HRV and neurochemistry biomarkers of synaptic plasticity in AMY and aHIP. HRV indices were obtained from the resting state electrocardiogram of patients with drug-resistant mesial temporal lobe epilepsy (MTLE, n = 18) and the levels of P-GluA1-Ser845 and P-GluA1-Ser831 in the AMY and aHIP resected during the epilepsy surgery. A backward stepwise multiple linear regression models were used to analyze the association between HRV and synaptic plasticity biomarkers controlling for imbalances in the distribution of sociodemographic, clinical, neuroimaging, and neurosurgical variables. P-GluA1-Ser845 levels in AMY show a negative association (p < 0.05) with the 3 investigated parasympathetic autonomic HRV indices (SDNN, rMSSD, and HF) predicting 24 to 40% of their variation. The final multiple linear regression models include disease duration and levels of P-GluA1-Ser845 and predict 24 to 56% of cardiac autonomic tone variation (p < 0.01). P-GluA1-Ser845 levels in AMY and aHIP are negatively associated with the resting HRV in MTLE-HS indicating that increased synaptic efficiency in amygdala is associated with a parasympathetic cardiac autonomic tone impairment. The results suggest that specific changes in synaptic plasticity may be involved in the brain-heart axis regulation by the limbic system.
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Sistema Nervioso Autónomo/metabolismo , Corazón/inervación , Sistema Límbico/metabolismo , Fosfoserina/metabolismo , Receptores AMPA/metabolismo , Amígdala del Cerebelo/metabolismo , Biomarcadores/metabolismo , Femenino , Frecuencia Cardíaca , Hipocampo/metabolismo , Humanos , Masculino , Plasticidad Neuronal , FosforilaciónRESUMEN
Cholinesterase inhibitors are used in postmenopausal women for the treatment of neurodegenerative diseases. Despite their widespread use in the clinical practice, little is known about the impact of augmented cholinergic signaling on cardiac function under reduced estrogen conditions. To address this gap, we subjected a genetically engineered murine model of systemic vesicular acetylcholine transporter overexpression (Chat-ChR2) to ovariectomy and evaluated cardiac parameters. Left-ventricular function was similar between Chat-ChR2 and wild-type (WT) mice. Following ovariectomy, WT mice showed signs of cardiac hypertrophy. Conversely, ovariectomized (OVX) Chat-ChR2 mice evolved to cardiac dilation and failure. Transcript levels for cardiac stress markers atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) were similarly upregulated in WT/OVX and Chat-ChR2/OVX mice. 17ß-Estradiol (E2) treatment normalized cardiac parameters in Chat-ChR2/OVX to the Chat-ChR2/SHAM levels, providing a link between E2 status and the aggravated cardiac response in this model. To investigate the cellular basis underlying the cardiac alterations, ventricular myocytes were isolated and their cellular area and contractility were assessed. Myocytes from WT/OVX mice were wider than WT/SHAM, an indicative of concentric hypertrophy, but their fractional shortening was similar. Conversely, Chat-ChR2/OVX myocytes were elongated and presented contractile dysfunction. E2 treatment again prevented the structural and functional changes in Chat-ChR2/OVX myocytes. We conclude that hypercholinergic mice under reduced estrogen conditions do not develop concentric hypertrophy, a critical compensatory adaptation, evolving toward cardiac dilation and failure. This study emphasizes the importance of understanding the consequences of cholinesterase inhibition, used clinically to treat dementia, for cardiac function in postmenopausal women.
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Acetilcolina/metabolismo , Fibras Colinérgicas/metabolismo , Estrógenos/deficiencia , Corazón/inervación , Hipertrofia Ventricular Izquierda/metabolismo , Miocitos Cardíacos/metabolismo , Disfunción Ventricular Izquierda/metabolismo , Función Ventricular Izquierda , Remodelación Ventricular , Proteínas de Transporte Vesicular de Acetilcolina/metabolismo , Animales , Estradiol/farmacología , Terapia de Reemplazo de Estrógeno , Femenino , Frecuencia Cardíaca , Hipertrofia Ventricular Izquierda/patología , Hipertrofia Ventricular Izquierda/fisiopatología , Hipertrofia Ventricular Izquierda/prevención & control , Ratones Endogámicos C57BL , Ratones Transgénicos , Contracción Miocárdica , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Ovariectomía , Transducción de Señal , Disfunción Ventricular Izquierda/patología , Disfunción Ventricular Izquierda/fisiopatología , Disfunción Ventricular Izquierda/prevención & control , Función Ventricular Izquierda/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacos , Proteínas de Transporte Vesicular de Acetilcolina/genéticaRESUMEN
The bed nucleus of the stria terminalis (BNST) is a forebrain structure, involved in the modulation of neuroendocrine, cardiovascular and autonomic responses. One of the responses is baroreflex activity, which consists in a neural mechanism responsible for keeping the blood pressure within a narrow range of variation. It has been reported that blockade of BNST α1-adrenoceptors increased the bradycardic component of baroreflex. In addition, such receptors are able to modulate glutamate release in this structure. Interestingly, BNST NMDA receptor antagonism and neuronal nitric oxide synthase (nNOS) inhibition led to the same effect of the α1-adrenoceptors blockade on baroreflex bradycardic response. Therefore, the hypothesis of the present study is that BNST noradrenergic transmission interacts with NMDA/NO pathway through α1 adrenoceptors to modulate the baroreflex activity. Male Wistar rats had stainless steel guide cannulas bilaterally implanted in the BNST. Subsequently, a catheter was inserted into the femoral artery for cardiovascular recordings, and into the femoral vein for assessing baroreflex activation. Injection of the noradrenaline reuptake inhibitor reboxetine in the BNST did not modify the tachycardic, but significantly decreased the bradycardic component of baroreflex. Administration of an α1, but not an α2 antagonist into the BNST prior to reboxetine prevented this effect. Likewise, previous injection of NMDA/NO pathway blockers inhibited the effect of reboxetine on bradycardic response. In conclusion, it was demonstrated for the first time the existence of an interaction between BNST noradrenergic, glutamatergic and nitrergic neurotransmissions in the modulation of bradycardic baroreflex response.
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Sistema Nervioso Autónomo/fisiología , Barorreflejo , Corazón/inervación , Óxido Nítrico/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Núcleos Septales/metabolismo , Animales , Presión Arterial , Sistema Nervioso Autónomo/efectos de los fármacos , Barorreflejo/efectos de los fármacos , Frecuencia Cardíaca , Masculino , Neurotransmisores/farmacología , Ratas Wistar , Receptores Adrenérgicos alfa 1/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Núcleos Septales/efectos de los fármacos , Factores de TiempoRESUMEN
BACKGROUND AND AIMS: Consumption of a high caloric diet induces autonomic imbalance, which can lead to cardiovascular disease. Impaired arterial baroreflex control is suggested to play an important role in cardiovascular autonomic imbalance, often seen in obesity. We previously demonstrated that cafeteria diets increase the sympathetic drive to white and brown adipose tissue. METHODS AND RESULTS: After feeding a cafeteria diet to rats for 26 days, we evaluated: (i)heart rate (HR) and arterial pressure (AP); (ii)baroreflex and chemoreflex function; and (iii) autonomic modulation of the heart and vessels, measured through pulse interval (PI) and systolic arterial pressure (SAP) variability analyses and following administration of autonomic blockers. The cafeteria diet increased body fat mass and serum insulin, leptin, triacylglycerol and cholesterol levels. Baseline HR (15%) was also increased, accompanied by increased power in the low frequency band (60%) and in the low frequency/high frequency ratio (104%) in the PI spectra. Nonlinear analysis revealed an increased occurrence of 0V (39%) and decreased occurrence of 2UV (18%) patterns. Following administration of autonomic blockers, we observed an increase in cardiac sympathetic tone (425%) in cafeteria diet-fed rats. The cafeteria diet had no effect on AP, SAP variability, baroreflex and chemoreflex control. CONCLUSION: Our findings suggest that consumption of a cafeteria diet increases sympathetic drive to the heart but not to the blood vessels, independent of impairment in baroreflex and chemoreflex functions. Other mechanisms may be involved in the increased cardiac sympathetic drive, and compensatory vascular mechanisms may prevent the development of hypertension in this model of obesity.
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Barorreflejo , Células Quimiorreceptoras/metabolismo , Dieta , Ingestión de Energía , Corazón/inervación , Obesidad/fisiopatología , Sistema Nervioso Simpático/fisiopatología , Animales , Presión Arterial , Modelos Animales de Enfermedad , Frecuencia Cardíaca , Masculino , Obesidad/etiología , Obesidad/metabolismo , Ratas Wistar , Factores de TiempoRESUMEN
. Background and Objectives: Cirrhosis is a liver disease that causes about one million deaths annually worldwide. The estimated cirrhosis prevalence ranges from 4.5-9.5% in the general population. Up to 40% of cirrhotic patients are asymptomatic and may be diagnosed late. Studies have described the importance of the functions of the liver and autonomic nervous system (ANS) and their relationship. There is limited information available on non-alcoholic cirrhosis and heart rate variability (HRV), which is a measure of the ANS. This study aimed to evaluate cardiac autonomic modulation through HRV in non-alcoholic cirrhosis individuals reported in previous observational and clinical trial studies. Materials and Methods: We performed a systematic review according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement using the Medline, Scopus, and Web of Science electronic databases. Five studies were identified and reviewed. Results: HRV was decreased in patients with non-alcoholic cirrhosis, even in the first stage. Conclusions: HRV could be used as a complementary method to improve both the diagnosis and prognosis of non-alcoholic cirrhosis.
Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Frecuencia Cardíaca , Corazón/inervación , Corazón/fisiopatología , Cirrosis Hepática/fisiopatología , Femenino , Humanos , MasculinoRESUMEN
To analyze whether heart rate variability is reproducible after maximal exercise, 11 men (22.1±3.2 years) performed four incremental exercise tests followed by passive or active recovery. There was high reliability (intraclass coefficient correlation: 0.72-0.96) and fair-to-excellent agreement (coefficient of variation: 7.81-22.09%) in passive recovery, as well as moderate-to-high reliability (intraclass coefficient correlation: 0.50-0.87) and good agreement (coefficient of variation: 11.08-20.89%) in active recovery for LnRMSSD index. There was moderate-to-high reliability (intraclass coefficient correlation: 0.51-0.81) and good agreement (coefficient of variation: 10.41-18.87%) in most of the analyzed time points, in both recovery types for LnSDNN. In both types of recovery, the time domain heart rate variability 5-10 min indices (passive: intraclass coefficient correlation : 0.87-0.88; coefficient of variation: 7.67-13.44%; active: intraclass coefficient correlation 0.59-0.80; coefficient of variation: 14.62-16.26%) presented higher intraclass coefficient correlation and lower coefficient of variation than the spectral heart rate variability indices (passive: intraclass coefficient correlation: 0.71-0.87; coefficient of variation: 12.33-34.21%; active: intraclass coefficient correlation: 0.46-0.77; coefficient of variation: 24.41-105.12%). The LnRMSSD and LnSDNN indices analyzed in 30 s segments and the heart rate variability 5-10 min indices after maximal exercise in untrained healthy men showed satisfactory reproducibility, regardless of the type of recovery, with the time-domain indices showing higher reproducibility than the frequency-domain indices.
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Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Prueba de Esfuerzo , Corazón/inervación , Humanos , Masculino , Sistema Nervioso Parasimpático/fisiología , Reproducibilidad de los Resultados , Sistema Nervioso Simpático/fisiología , Adulto JovenRESUMEN
BACKGROUND AND AIMS: Metformin has been known to promote cardiovascular benefits in humans and animal models, even in non-diabetic subjects. However, its chronic effects on hypertension-related autonomic dysfunction remain poorly understood. Therefore, we evaluate the cardiac autonomic effects of chronic metformin in hypertensive rats. METHODS AND RESULTS: Twelve-week-old male SHR and Wistar rats were separated into 3 groups: WN (Wistar normotensive); SC (SHR hypertensive control); and SM (SHR: Metformin 300 mg/kg/day for 30 days). Spontaneous and induced (by phenylephrine and sodium nitroprusside) baroreflexes were analysed in catheterised rats. Next, cardiac autonomic tone was evaluated through heart rate shift by atropine (parasympathetic) or atenolol (sympathetic). Plasma TNFα was assessed by ELISA. Western blot analyses of inflammatory, oxidant and antioxidant proteins were performed. Cardiac parasympathetic tone and baroreflex function were lower in SC than in WN, whereas cardiac sympathetic tone was higher. Metformin treatment in non-diabetic hypertensive rats reduced the resting heart rate, attenuated the cardiac sympathetic tone and improved baroreflex (especially in the offsetting of rising BP), while blood pressure and glycaemia remained unchanged. Cardiac sympathetic tone correlated negatively with spontaneous baroreflex. Metformin reduced plasma TNFα levels and decreased tissue expression of COX2 and NOX2 (which were positively correlated), without affecting SOD1 and SOD2. CONCLUSION: Chronic metformin presented anti-inflammatory and antioxidant effects and, independently of alterations in glycaemia, it improved cardiac autonomic parameters that are impaired in hypertension, being related to end-organ damage and mortality. These findings open up perspectives for future innovative uses of metformin in cardiovascular diseases, especially in hypertension.
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Antiinflamatorios/farmacología , Antihipertensivos/farmacología , Sistema Nervioso Autónomo/efectos de los fármacos , Barorreflejo/efectos de los fármacos , Corazón/inervación , Hipertensión/tratamiento farmacológico , Mediadores de Inflamación/sangre , Metformina/farmacología , Animales , Antioxidantes/metabolismo , Sistema Nervioso Autónomo/metabolismo , Sistema Nervioso Autónomo/fisiopatología , Biomarcadores/sangre , Presión Sanguínea/efectos de los fármacos , Modelos Animales de Enfermedad , Regulación hacia Abajo , Frecuencia Cardíaca/efectos de los fármacos , Hipertensión/sangre , Hipertensión/fisiopatología , Masculino , Ratas Endogámicas SHR , Ratas WistarRESUMEN
Several studies have reported that high doses of synthetic anabolic androgenic steroids (AAS) can have serious negative effects on health, including the cardiovascular system. The aim of this study was to evaluate the combined effects of AAS and exercise training on ventricular repolarization and cardiac autonomic modulation in rats. Male Wistar rats were allocated into 4 groups: sedentary rats treated with vehicle, sedentary rats treated with nandrolone decanoate, swimming-trained rats treated with vehicle, and swimming-trained rats treated with nandrolone decanoate. Ventricular repolarization was evaluated by electrocardiographic analysis of QT interval and QT dispersion. Cardiac autonomic modulation was assessed by heart rate variability. Our results show that AAS increased QT interval and QT dispersion in sedentary rats treated with nandrolone decanoate as compared to sedentary rats treated with vehicle, indicating AAS-induced ventricular repolarization abnormalities. When rats treated with nandrolone decanoate were subjected to concomitant exercise training, ventricular repolarization was normalized. On the other hand, AAS-induced reduction in cardiac parasympathetic modulation was not prevented by exercise training. In conclusion, AAS produced cardiac autonomic dysfunction and ventricular repolarization disturbances in rats. Combining an exercise training protocol during the AAS treatment attenuated the ventricular repolarization abnormalities and did not prevent cardiac autonomic dysfunction.
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Sistema Nervioso Autónomo/efectos de los fármacos , Sistema Nervioso Autónomo/fisiología , Ventrículos Cardíacos/efectos de los fármacos , Corazón/inervación , Condicionamiento Físico Animal , Congéneres de la Testosterona/farmacología , Tejido Adiposo/citología , Tejido Adiposo/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Peso Corporal/fisiología , Relación Dosis-Respuesta a Droga , Electrocardiografía/efectos de los fármacos , Corazón/efectos de los fármacos , Corazón/fisiología , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Masculino , Tamaño de los Órganos/efectos de los fármacos , Tamaño de los Órganos/fisiología , Ratas , Ratas Wistar , Función Ventricular/efectos de los fármacosRESUMEN
BACKGROUND: Premature infants may present with damage to the autonomic nervous system (ANS), which may be related to poorer neurological development. Among the techniques used to evaluate the ANS, heart rate variability (HRV) emerged as a simple, non-invasive, and easy to apply tool. The aim of the present study was to analyze and compare HRV in preterm infants at different times of hospitalization in order to verify the possible environmental relationships or clinical evolution with HRV. METHODS: A longitudinal, prospective, and descriptive study with non-probabilistic sampling composed of 25 collections of preterm infants of HRV at two moments: moment I (within 15 days of birth) and moment II (after 45 days post-birth). The Polar V800 heart rate monitor was used with the Polar H10 cardiac transducer to collect HRV, which was collected in the supine position for 15 min. The HRV data were analyzed by the linear method in frequency domain and time domain and by the nonlinear method using Kubios HRV analysis software, version 3.0.2. RESULTS: There was an increase in HRV values at moment II, these being statistically significant in the SD1, ApEn, and SampEn. Data related to increased sympathetic nervous system activity, parasympathetic nervous system activity, and increased index complexity. CONCLUSIONS: The data demonstrate an increase in HRV values in premature infants at moment II, demonstrating a possible development in the maturation of the ANS during hospitalization. TRIAL REGISTRATION: RBR-3x7gz8 retrospectively registered.