Mário Augusto Paschoal

Variabilidade da freqüência cardíaca em diferentes faixas etárias

Heart Rate Variability in Different Age Groups Objective: To study the heart rate variability (HRV) of 40 healthy volunteers of different ages, divided into four equal groups, with the following characteristics: a) group 1, 20 to 30 years old (mean ± standard deviation = 23.0 ± 2.8 years); b) group 2, 31 to 40 years old (34.7 ± 2.1 years); c) group 3, 41 to 50 years old (46.4 ± 3.4 years); and group 4, 51 to 60 years old (54.9 ± 2.0 years). Method: The investigation tool was HRV in the time (TD) and frequency (FD) domains, in two situations: 1) under controlled resting conditions (CRC); 2) during active postural maneuvers (APM). Results: Under CRC, the HRV in TD and FD was lower in the 51-60 age group than in the 20-30, 31-40 and 41-50 groups. During APM, comparison between the supine and biped positions within the groups showed that there was a progressive reduction in the magnitude of sympathetic and parasympathetic responses as subject ages increased. Analysis of 0-10s heart rate delta (Δ 0-10s) for changing from the supine to the biped position also showed progressive reduction with aging: means of +42 bpm, +35 bpm, +30 bpm and +25 bpm, respectively for the 20-30, 31-40, 41-50 and 51-60 age groups. Conclusion: HRV analysis, both under CRC and during APM, is an important tool for investigating cardiac autonomic function in relation to human aging.

Heart rate variability, blood lipids and physical capacity of obese and non-obese children.

FUNDAMENTO: La obesidad puede afectar la modulacion autonomica cardiaca, los lipidos de la sangre y la capacidad fisica. OBJETIVO: Estudiar la interferencia de la obesidad sobre la variabilidad de la frecuencia cardiaca (VFC), los lipidos de la sangre y la capacidad fisica de ninos obesos. METODOS: Se estudiaron a 30 ninos con edades entre 9 y 11 anos, divididos en dos grupos: a) 15 ninos obesos (O) con 10,2 ± 0,7 anos de edad e indice de masa corporal (IMC) en el percentil entre 95 y 97; b) 15 ninos no obesos (NO) con 9,8 ± 0,7 anos de edad e IMC en el percentil entre 5 y 85. Todos se sometieron a evaluacion antropometrica y clinica, analisis de la VFC al reposo y a un protocolo de esfuerzo (PE). Se utilizaron pruebas no parametricas para comparar las variables entre los grupos, y el nivel de significancia aplicado fue de p < 0,05. RESULTADOS: La circunferencia abdominal y los niveles de trigliceridos fueron mayores en O. La actividad simpatica cardiaca, en la posicion bipeda, en unidades normalizadas -BFun, fue mayor para los O, con el 71,4%, cuando comparada al 56,3% de NO; y la razon baja/alta frecuencia (BF/AF) fue del 3,8 para O y 1,7 para NO. En el PE se constataron diferencias entre los grupos, con mayores valores para los ninos NO, en cuanto la distancia total, el tiempo de exposicion al PE, consumo de oxigeno pico (VO2 pico) y equivalente metabolico (MET). CONCLUSION: La obesidad infantil provoco modificaciones en el control autonomico cardiaco en la posicion bipeda y reduzco la capacidad fisica.BACKGROUND Obesity can affect the cardiac autonomic modulation, blood lipid levels and the physical capacity. OBJECTIVE To study the effect of obesity on the heart rate variability (HRV), blood lipid levels and physical capacity of obese children. METHODS Thirty children aged 9 to 11 years were studied, divided in two groups: a) 15 obese children (O) aged 10.2 +/- 0.7 years and body mass index (BMI) between the 95th and the 97th percentiles; b) 15 non-obese children (NO) aged 9.8 +/- 0.7 years and BMI between the 5th and 85th percentiles. All children were submitted to an anthropometric and clinical assessment, analysis of the HRV at rest and a physical exercise protocol (PEP). Non-parametric tests were used to compare the variables between the groups. The level of significance was set at p < 0.05. RESULTS The waist circumference and levels of triglycerides were higher in O. The cardiac sympathetic activity in the standing position in normalized units (LF n.u.) was higher in O, 71.4%, when compared to NO, 56.3%. The low frequency/high frequency ratio (LF/HF) was 3.8 in O and 1.7 in NO. The PEP showed differences between the groups, with higher values observed in NO children regarding the total distance, time of exposure to PEP, peak oxygen consumption (VO2 peak) and metabolic equivalent (MET). CONCLUSION Obesity in children resulted in alterations in cardiac autonomic control in the standing position and decreased the physical capacity.

Variabilidade da frequência cardíaca, lípides e capacidade física de crianças obesas e não-obesas

FUNDAMENTO: La obesidad puede afectar la modulacion autonomica cardiaca, los lipidos de la sangre y la capacidad fisica. OBJETIVO: Estudiar la interferencia de la obesidad sobre la variabilidad de la frecuencia cardiaca (VFC), los lipidos de la sangre y la capacidad fisica de ninos obesos. METODOS: Se estudiaron a 30 ninos con edades entre 9 y 11 anos, divididos en dos grupos: a) 15 ninos obesos (O) con 10,2 ± 0,7 anos de edad e indice de masa corporal (IMC) en el percentil entre 95 y 97; b) 15 ninos no obesos (NO) con 9,8 ± 0,7 anos de edad e IMC en el percentil entre 5 y 85. Todos se sometieron a evaluacion antropometrica y clinica, analisis de la VFC al reposo y a un protocolo de esfuerzo (PE). Se utilizaron pruebas no parametricas para comparar las variables entre los grupos, y el nivel de significancia aplicado fue de p < 0,05. RESULTADOS: La circunferencia abdominal y los niveles de trigliceridos fueron mayores en O. La actividad simpatica cardiaca, en la posicion bipeda, en unidades normalizadas -BFun, fue mayor para los O, con el 71,4%, cuando comparada al 56,3% de NO; y la razon baja/alta frecuencia (BF/AF) fue del 3,8 para O y 1,7 para NO. En el PE se constataron diferencias entre los grupos, con mayores valores para los ninos NO, en cuanto la distancia total, el tiempo de exposicion al PE, consumo de oxigeno pico (VO2 pico) y equivalente metabolico (MET). CONCLUSION: La obesidad infantil provoco modificaciones en el control autonomico cardiaco en la posicion bipeda y reduzco la capacidad fisica.BACKGROUND Obesity can affect the cardiac autonomic modulation, blood lipid levels and the physical capacity. OBJECTIVE To study the effect of obesity on the heart rate variability (HRV), blood lipid levels and physical capacity of obese children. METHODS Thirty children aged 9 to 11 years were studied, divided in two groups: a) 15 obese children (O) aged 10.2 +/- 0.7 years and body mass index (BMI) between the 95th and the 97th percentiles; b) 15 non-obese children (NO) aged 9.8 +/- 0.7 years and BMI between the 5th and 85th percentiles. All children were submitted to an anthropometric and clinical assessment, analysis of the HRV at rest and a physical exercise protocol (PEP). Non-parametric tests were used to compare the variables between the groups. The level of significance was set at p < 0.05. RESULTS The waist circumference and levels of triglycerides were higher in O. The cardiac sympathetic activity in the standing position in normalized units (LF n.u.) was higher in O, 71.4%, when compared to NO, 56.3%. The low frequency/high frequency ratio (LF/HF) was 3.8 in O and 1.7 in NO. The PEP showed differences between the groups, with higher values observed in NO children regarding the total distance, time of exposure to PEP, peak oxygen consumption (VO2 peak) and metabolic equivalent (MET). CONCLUSION Obesity in children resulted in alterations in cardiac autonomic control in the standing position and decreased the physical capacity.

Avaliação da variabilidade da freqüência cardíaca em mulheres climatéricas treinadas e sedentárias

BACKGROUND Changes in autonomic cardiac function are frequent during menopause, and various methods have been used to understand and minimize them. OBJECTIVE To study the interference of dynamic aerobic physical activity on heart rate variability (HRV) in climacteric women. METHODS Cross-sectional study that analyzed HRV in 15 menopausal women (mean age 56.8+/-4.9 years) who had participated in physical training (one-hour walks, 3 times a week) for at least two years (active group), and 15 menopausal women (mean age 56.5 +/- 3.7 years) who were sedentary (sedentary group). None of the volunteers received hormonal replacement therapy. HRV data were compared between the groups by means of the Mann Whitney U Test. RESULTS There were significant differences both in the frequency and time domains of the following variables of HRV (in medians) for the active e sedentary groups, respectively: total power (22,626.50 ms(2) and 4,432.10 ms(2)), low frequency component (741.20 ms(2) and 131.70 ms(2)), high frequency component (668.90 ms(2) and 131.70 ms(2)), standard deviations of RR intervals (51.60 ms and 22.50 ms), square root of the sum of squares of differences between the normal RR intervals (35.30 ms and 15.90 ms), and percentage of normal adjacent RR intervals greater than 50 ms (6.6% and 0.2%). CONCLUSION The study suggests that aerobic training may have afforded a significant improvement in the autonomic cardiac function of the menopausal women in the active group, and may be a useful option for preserving this functional condition without the need for hormonal replacement therapy.

Method of heart rate variability threshold applied in obese and non-obese pre-adolescents

BACKGROUND: La deteccion del umbral anaerobico (UA) por el analisis de la variabilidad de la frecuencia cardiaca (LiVFC) puede significar una nueva manera de evaluacion de la capacidad funcional cardiorrespiratoria (CFCR) en preadolescentes. OBJECTIVE: Testear el metodo de LiVFC para deteccion del UA en preadolescentes no obesos (NO), obesos (O) y obesos morbidos (OM), a fin de determinar diferencias en su CFCR. METHODS: Fueron estudiados 30 preadolescentes, con edades entre 9 y 11 anos, divididos en tres grupos de 10: a) grupo NO - indice de masa corporal (IMC) con percentil del National Center for Chronic Disease Prevention and Health Promotion entre 5 y 85; b) grupo O - IMC de percentil entre 95 y 97 y c) grupo OM - IMC con percentil encima de 97. Todos fueron sometidos a un protocolo incremental realizado en cinta rodante y se registraron los latidos cardiacos para deteccion del LiVFC, que fue determinado por el valor de 3,0 ms del indice de desviacion-estandar 1 (SD1), extraido de los intervalos RR. RESULTS: Los valores medios en el momento del LiVFC mostraron mayores valores para el grupo NO, destacandose: a) VO2 (ml/kg/min) NO = 27,4 ± 9,2; O = 13,1 ± 7,6 y OM = 11,0 ± 1,7; b) FC (lpm): NO = 156,3 ± 18,0; O =141,7 ± 11,4 y OM = 137,7 ± 10,4; y c) distancia recorrida (metros): NO = 1.194,9 ± 427,7; O = 503,2 ± 437,5 y OM = 399,9 ± 185,1. CONCLUSION: El LiVFC se mostro efectivo para evaluacion de la CFCR y podra comenzar a ser aplicado como metodo alternativo a la ergoespirometria en determinadas situaciones.BACKGROUND The detection of anaerobic threshold (AT) by heart rate variability analysis (HRVt) may mean a new way to assess the cardiorespiratory capacity (CRC) in pre-adolescents. OBJECTIVE To test the method of HRVt to detect AT in non-obese (NO), obese (O) and morbidly obese (MO) pre-adolescents in order to determine differences in their CRC. METHODS Were studied 30 pre-adolescents, aged between 9 and 11 years, divided into three groups of ten pre-adolescents each: a) NO group - body mass index (BMI) between 5 and 85 percentiles of the chart of National Center for Chronic Disease Prevention and Health Promotion.; b) O group - BMI between 95 and 97 of the same chart; c) MO group - BMI with percentile over 97. All were submitted to an incremental protocol conducted on a treadmill, and the heart rate was recorded for the detection of the HRVt when the beat-to-beat variability (SD1), extracted from the RR intervals, reached the value of 3 ms. RESULTS The mean values obtained at HRVt were higher for the NO group, which included: a) VO2 (ml/kg/min) NO = 27.4 ± 9.2; O = 13.1 ± 7.6, and MO = 11.0 ± 1.7 b) HR (bpm): NO = 156.3 ± 18.0, O = 141.7 ± 11.4 and 137.7 ± 10.4 MO; c) distance (m): NO = 1,194.9 ± 427.7, O = 503.2 ± 437.5 and MO = 399.9 ± 185.1. CONCLUSION HRVt was effective for evaluation of CRC and could be applied as an alternative method to ergoespirometry in certain situations.

Método do limiar de variabilidade da frequência cardíaca aplicado em pré-adolescentes obesos e não obesos

BACKGROUND: La deteccion del umbral anaerobico (UA) por el analisis de la variabilidad de la frecuencia cardiaca (LiVFC) puede significar una nueva manera de evaluacion de la capacidad funcional cardiorrespiratoria (CFCR) en preadolescentes. OBJECTIVE: Testear el metodo de LiVFC para deteccion del UA en preadolescentes no obesos (NO), obesos (O) y obesos morbidos (OM), a fin de determinar diferencias en su CFCR. METHODS: Fueron estudiados 30 preadolescentes, con edades entre 9 y 11 anos, divididos en tres grupos de 10: a) grupo NO - indice de masa corporal (IMC) con percentil del National Center for Chronic Disease Prevention and Health Promotion entre 5 y 85; b) grupo O - IMC de percentil entre 95 y 97 y c) grupo OM - IMC con percentil encima de 97. Todos fueron sometidos a un protocolo incremental realizado en cinta rodante y se registraron los latidos cardiacos para deteccion del LiVFC, que fue determinado por el valor de 3,0 ms del indice de desviacion-estandar 1 (SD1), extraido de los intervalos RR. RESULTS: Los valores medios en el momento del LiVFC mostraron mayores valores para el grupo NO, destacandose: a) VO2 (ml/kg/min) NO = 27,4 ± 9,2; O = 13,1 ± 7,6 y OM = 11,0 ± 1,7; b) FC (lpm): NO = 156,3 ± 18,0; O =141,7 ± 11,4 y OM = 137,7 ± 10,4; y c) distancia recorrida (metros): NO = 1.194,9 ± 427,7; O = 503,2 ± 437,5 y OM = 399,9 ± 185,1. CONCLUSION: El LiVFC se mostro efectivo para evaluacion de la CFCR y podra comenzar a ser aplicado como metodo alternativo a la ergoespirometria en determinadas situaciones.BACKGROUND The detection of anaerobic threshold (AT) by heart rate variability analysis (HRVt) may mean a new way to assess the cardiorespiratory capacity (CRC) in pre-adolescents. OBJECTIVE To test the method of HRVt to detect AT in non-obese (NO), obese (O) and morbidly obese (MO) pre-adolescents in order to determine differences in their CRC. METHODS Were studied 30 pre-adolescents, aged between 9 and 11 years, divided into three groups of ten pre-adolescents each: a) NO group - body mass index (BMI) between 5 and 85 percentiles of the chart of National Center for Chronic Disease Prevention and Health Promotion.; b) O group - BMI between 95 and 97 of the same chart; c) MO group - BMI with percentile over 97. All were submitted to an incremental protocol conducted on a treadmill, and the heart rate was recorded for the detection of the HRVt when the beat-to-beat variability (SD1), extracted from the RR intervals, reached the value of 3 ms. RESULTS The mean values obtained at HRVt were higher for the NO group, which included: a) VO2 (ml/kg/min) NO = 27.4 ± 9.2; O = 13.1 ± 7.6, and MO = 11.0 ± 1.7 b) HR (bpm): NO = 156.3 ± 18.0, O = 141.7 ± 11.4 and 137.7 ± 10.4 MO; c) distance (m): NO = 1,194.9 ± 427.7, O = 503.2 ± 437.5 and MO = 399.9 ± 185.1. CONCLUSION HRVt was effective for evaluation of CRC and could be applied as an alternative method to ergoespirometry in certain situations.

Proposal Intensity Adequacy of Expiratory Effort and Heart Rate Behavior During the Valsalva Maneuver in Preadolescents

Background When performing the Valsalva maneuver (VM), adults and preadolescents produce the same expiratory resistance values. Objective To analyze heart rate (HR) in preadolescents performing VM, and propose a new method for selecting expiratory resistance. Method The maximal expiratory pressure (MEP) was measured in 45 sedentary children aged 9-12 years who subsequently performed VM for 20 s using an expiratory pressure of 60%, 70%, or 80% of MEP. HR was measured before, during, and after VM. These procedures were repeated 30 days later, and the data collected in the sessions (E1, E2) were analyzed and compared in periods before, during (0-10 and 10-20 s), and after VM using nonparametric tests. Results All 45 participants adequately performed VM in E1 and E2 at 60% of MEP. However, only 38 (84.4%) and 25 (55.5%) of the participants performed the maneuver at 70% and 80% of MEP, respectively. The HR delta measured during 0-10 s and 10-20 s significantly increased as the expiratory effort increased, indicating an effective cardiac autonomic response during VM. However, our findings suggest the VM should not be performed at these intensities. Conclusion HR increased with all effort intensities tested during VM. However, 60% of MEP was the only level of expiratory resistance that all participants could use to perform VM. Therefore, 60% of MEP may be the optimal expiratory resistance that should be used in clinical practice.

Influence of classic massage on cardiac autonomic modulation

Introduction: Massage can be defined as the rhythmic and smooth manipulation of body tissues, with the aim to promote health and well-being. Objective: To assess the influence of classic massage on cardiac autonomic modulation. Methods: Cross-sectional study that evaluated healthy participants, with mean age between 18 and 25 years, divided into two groups: test group (TG, n=11) and control group (CG, n=10). The TG had their heartbeat recorded for 5min before receiving a classic massage for 40min and during three periods after this procedure: 0-5min, 5-10min and 10-15min. The CG had their heartbeats recorded at the same time; without receive massage. Cardiac autonomic modulation was investigated by heart rate variability (HRV). Results: The mean values of HRV rates were: pNN50, respectively, for the TG: before massage (10.5 ± 9.5%), and after massage: 0-5min (11.6 ± 7.2%), 5-10min (12.1 ± 8.0%) and 10-15min (11.1 ± 7.9%), with no significant statistical difference. The same result was found for the mean values of rMSSD index of the TG; before massage: 52.1 ± 46.2 ms, and after massage: 0-5min (50.0 ± 21.6ms), 5-10min (52.0 ± 27.4 ms) and 10-15min (48.2 ± 21.1 ms). Also, the values of LFnuand HFnu indexes did not change significantly before and after massage, and they were not statistically different from the values presented by the control group. Conclusion: The study results suggest that one session of classic massage does not modify cardiac autonomic modulation in healthy young adults.

Cardiac Autonomic Adjustments During Baroreflex Test in Obese and Non-Obese Preadolescents

Background Recent studies have shown changes in cardiac autonomic control of obese preadolescents. Objective To assess the heart rate responses and cardiac autonomic modulation of obese preadolescents during constant expiratory effort. Methods This study assessed 10 obese and 10 non-obese preadolescents aged 9 to 12 years. The body mass index of the obese group was between the 95th and 97th percentiles of the CDC National Center for Health Statistics growth charts, while that of the non-obese group, between the 5th and 85th percentiles. Initially, they underwent anthropometric and clinical assessment, and their maximum expiratory pressures were obtained. Then, the preadolescents underwent a constant expiratory effort of 70% of their maximum expiratory pressure for 20 seconds, with heart rate measurement 5 minutes before, during and 5 minutes after it. Heart rate variability (HRV) and heart rate values were analyzed by use of a software. Results The HRV did not differ when compared before and after the constant expiratory effort intra- and intergroup. The heart rate values differed (p < 0.05) during the effort, being the total variation in non-obese preadolescents of 18.5 ± 1.5 bpm, and in obese, of 12.2 ± 1.3 bpm. Conclusion The cardiac autonomic modulation did not differ between the groups when comparing before and after the constant expiratory effort. However, the obese group showed lower cardiovascular response to baroreceptor stimuli during the effort, suggesting lower autonomic baroreflex sensitivity.

Perfil antropométrico e clínico de escolares e sua relação com a síndrome metabólica na infância - doi: 10.5020/18061230.2012.p202

Objective: To evaluate the anthropometric and clinical profile of students and verify its association with the metabolic syndrome. Methods: The study involved 91 students, aged 7 to 8, attending public schools in Campinas-SP, Brazil. All students were submitted to an evaluation of blood pressure and anthropometrical parameters, focused on weight, height, abdominal and brachial circumferences measurements. To evaluate the incidence of metabolic syndrome among those children, they were divided into groups according to nutritional status and body mass index distribution. Results: 45 children (49.4%) were considered eutrophic, 12 were overweight (13.1%) and 34 were obese (37.3%). Comparisons between abdominal and brachial circumferences were statistically different for the eutrophic (55.5±3.5 and 18.6±1.3), overweight (62.9±4,0 and 21.4±1.7) and obese group (76.3±8.1 and 26.5±2.6). Systolic blood pressure was lower in the eutrophic group, compared to the obese one, with values of 88.2±4,0 and 93.4±7.2 mmHg, respectively. Both systolic and diastolic blood pressure were correlated to abdominal circumference values in all groups. However, only systolic blood pressure showed correlation with brachial circumference in all groups. Conclusion: Given the significant correlation observed between both systolic and diastolic blood pressure values and abdominal circumference values; as well as between systolic blood pressure values and brachial circumference, the anthropometric and clinical evaluation is to be considered suitable for early detection and to control the risk of development of metabolic syndrome among the children in this study