Navegando por Palavras-chave "Cardiovascular System"

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    Análise da modulação autonômica da frequência cardíaca em indivíduos saudáveis expostos à poluição atmosférica por tempo prolongado
    (Universidade Federal de São Paulo (UNIFESP), 2019-06-26) Costa e Oliveira, Juliana Regis da[UNIFESP]; Ferreira, Celso [UNIFESP]; Ferreira Filho, Celso; http://lattes.cnpq.br/1788268008188276; http://lattes.cnpq.br/6851397444757156; http://lattes.cnpq.br/9086976469351911; Universidade Federal de São Paulo (UNIFESP)
    Objective. To analyze the autonomic modulation of heart rate in individuals exposed to air pollution for a long time. Method. We analyzed 109 individuals, aged between 18 and 49 years, living in an area contaminated by air pollution, located in the city of Cubatão (SP). The control area corresponded to the municipality of Peruíbe (SP). Intergroups were analyzed (experimental groups: 29 individuals living in the municipality of Cubatão and exposed for less than 15 years and 31 - individuals living in the municipality of Cubatão and exposed for more than 15 years, and 49 individuals in the control group) with linear indexes (frequency domain indexes - LF, HF and LF/HF, time domain - SDNN, Pnn50 and RMSSD, and geometric indexes - SD1, SD2, SD1/SD2, RRTri and TINN) and nonlinear (symbolic analysis and Entropy of Shannon) of VFC. Results. All the linear and geometric indexes of the time domain presented statistical significance, with the exception of the TINN index. There were differences between groups CG and E2, and E1 and E2 in relation to RMSSD (p = 0.033, p = 0.042), Pnn50 (p = 0.030, p = 0.042), SD1 (p = 0.034, p = 0.045) and RRTri (p = 0.016, p = 0.019), respectively. The difference found in the SD1/SD2 (p = 0.024) was observed only between the CG and E2 groups, and in the SDNN (p = 0.035) and SD2 (p = 0.041) only between the E1 and E2 groups. In the frequency domain, only the LFms2 index presented a statistically significant difference. In the post hoc test, differences between groups E2 and E1 (p = 0.041) were observed. Regarding the symbolic analysis and ES, all items appeared with statistical significance, except for the 1V index. In the post hoc analyzes, differences between the CG and E2 groups were found in the variables 0V (p = 0.014), 2LV (p = 0.014) and 2ULV (p = 0.015). The ES variable presented differences between all groups (CG and E1 p = 0.035, GC and E2 p = <0.001, E1 and E2 p = 0.029). Conclusion. It was concluded that the group of individuals exposed to air pollution for a period of more than 15 years presented lower parasympathetic modulation, less global HRV, and greater sympathetic modulation when compared to the control group. And when compared to the group of individuals exposed to air pollution for a period of less than 15 years, less parasympathetic modulation and global HRV occurred.
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    ATZ (3-amino-1,2,4-triazole) injected into the fourth cerebral ventricle influences the Bezold-Jarisch reflex in conscious rats
    (Faculdade de Medicina / USP, 2010-01-01) Valenti, Vitor Engrácia [UNIFESP]; Abreu, Luiz Carlos de; Sato, Monica A.; Ferreira, Celso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Faculdade de Medicina do ABC Departamento de Morfologia e Fisiologia
    OBJECTIVES: Many studies have investigated the importance of oxidative stress on the cardiovascular system. In this study we evaluated the effects of central catalase inhibition on cardiopulmonary reflex in conscious Wistar rats. METHODS: Male Wistar rats were implanted with a stainless steel guide cannula in the fourth cerebral ventricle. The femoral artery and vein were cannulated for mean arterial pressure and heart rate measurement and for drug infusion, respectively. After basal mean arterial pressure and heart rate recordings, the cardiopulmonary reflex was tested with a dose of phenylbiguanide (PBG, 8 μg/kg, bolus). Cardiopulmonary reflex was evaluated before and μl15 minutes after 1.0 μl 3-amino-1,2,4-triazole (ATZ, 0.01g/100μl)0.01 g/100 μl) injection into the fourth cerebral ventricle. Vehicle treatment did not change cardiopulmonary reflex responses. RESULTS: Central ATZ significantly increased hypotensive responses without influencing the bradycardic reflex. CONCLUSION: ATZ injected into the fourth cerebral ventricle increases sympathetic inhibition but does not change the parasympathetic component of the cardiopulmonary reflex in conscious Wistar rats.
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    Efeitos da privação de sono sobre parâmetros cardiovasculares em ratos machos e fêmeas
    (Universidade Federal de São Paulo (UNIFESP), 2011-06-29) Tenório, Neuli Maria [UNIFESP]; Andersen, Monica Levy [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Curtailment of sleep time is a characteristic of modern society, and the reciprocal association between duration of sleep and weight gain has been under scrutiny as of late. The consequences of such factors upon the cardiovascular system remain to be fully elucidated, particularly along a full life span. Moreover, the consequences of sleep deprivation may also be influenced by the gender. The current study thus purported to examine the impact of acute sleep deprivation associated to obesity in female Zucker rats of different ages (Paper 1) and to compare the effects of paradoxical sleep deprivation (PSD) and chronic sleep restriction (SR) in male and female eutrophic rats (Paper 2) upon the cardiovascular (Papers 1 and 2) and hormonal (Paper 2 ) parameters. For the experiments described in Paper 1 lean and obese female Zucker rats 3, 6, and 15 months old were distributed into either control groups (CTRL, homecage) or sleep deprived (SD). For the experiments of Paper 2 adult female and male Wistar rats were distributed in either control groups (CTRL, home-cage) or in Paradoxical Sleep Deprivation for 96h groups (PSD-96h) or Sleep Restriction for 21 days groups (SR 21 days). In both experiments the subjects were anesthetized according to respective SD protocol or equivalent time in the CTRL groups, after which a catheter was placed in their femoral artery and vein. The baroreflex sensibility index was measured by means of phenilephrine (bradicardiac response) and sodium nitroprussiate (taquicardiac response). For the experiments conducted for Paper 2 a different group of subjects was used for blood harvesting to assess the concentrations of adrenocorticotrophic hormone (ACTH). In Paper 1 we observed that obesity resulted in dysfunctional taquicardia in subjects from 3 months of age and on. At 6 and 15 months of age the bradicardiac and taquicardiac response were significantly smaller in obese subjects when compared to respective lean groups. At 15 months of age the interaction between obesity, SD and age caused the greatest consequences in the cardiovascular system as arterial. Results of Paper 2 show that the average arterial pressure was significantly higher in the SR group when compared to the CTRL group in both genders. In females, cardiac frequency was significantly higher after PSD when compared to respective controls. The SR protocol attenuated the vagal baroreflex response similarly in males and females. The sympathetic baroreflex response was attenuated in the PSD and SR groups, but in females this parameter was affected only after PSD. No significant difference in relation to gender was observed in any of the cardiovascular parameters. PSD did increase ACTH concentrations significantly when compared to controls of both genders. The body of results yielded by both studies suggests that different periods of lost sleep lead to specific consequences in cardiovascular and hormonal parameters, and such effects were similar in male and female rat subjects.
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    The effects of auditory stimulation with music on heart rate variability in healthy women
    (Faculdade de Medicina / USP, 2013-07-01) Roque, Adriano Luís; Valenti, Vitor Engrácia [UNIFESP]; Guida, Heraldo Lorena; Campos, Monica F.; Knap, Andre; Vanderlei, Luiz Carlos Marques; Ferreira, Lucas Lima; Ferreira, Celso [UNIFESP]; Abreu, Luiz Carlos de; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual Paulista (UNESP)
    OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n = 21), who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n = 19), who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB). A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB). The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio), low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. RESULTS: The triangular index and the standard deviation of the long-term RR interval indices were reduced during exposure to both music styles in the first group and tended to decrease in the second group whereas the white noise exposure decreased the high frequency index. We observed no changes regarding the triangular interpolation of RR intervals, standard deviation of instantaneous beat-by-beat variability and standard deviation of instantaneous beat-by-beat variability/standard deviation in the long-term RR interval ratio. CONCLUSION: We suggest that relaxant baroque and excitatory heavy metal music slightly decrease global heart rate variability because of the equivalent sound level.
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    Modulação autonômica cardíaca no modelo murino da Síndrome de Down - Ts65Dn
    (Universidade Federal de São Paulo (UNIFESP), 2019-12-18) Roque, Adriano Luis [UNIFESP]; Silva, Talita Dias Da [UNIFESP]; http://lattes.cnpq.br/9924565440571557; http://lattes.cnpq.br/1873750574811476; Universidade Federal de São Paulo (UNIFESP)
    Introduction: The Ts65Dn mouse is the most widely used animal model of Down syndrome (DS). Differences in autonomic regulation of heart rate variability (HRV) in individuals with DS have been hypothesized. Pharmacological studies in animal models may help us understand mechanisms underlying observed changes in HRV in people with DS. Objective: Characterize cardiac autonomic modulation in a mouse model of Down Syndrome. Method: We recorded electrocardiograms (ECGs) from 10 Ts65Dn and 10 euploid control mice. For analysis of the data, we considered 30 minutes of baseline, followed by injection of adrenergic (isoproterenol) or cholinergic (carbachol) agonists.HRV analysis was performed using linear indices in time domain. Results and Discussion: Our results allow us to raise other hypotheses that may be evaluated in future studies, the amount of drug-degrading enzymes present in these mice, the sensitivity of the animals to these chemicals, the amount of adrenergic and cholinergic receptors of the Ts65Dn mice. Ts65Dn mice showed a possible overexpression of the GIRK2 gene and it seems to have increased cholinergic response and, consequently explaining the increase in heart rate variability found in these mice models of DS Conclusion: Ts65Dn mice presents deficits in cardiac autonomic modulation when compared with the euploid control group, mainly due to the reduction of indices related to global modulation (SD2 and SDNN).
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    A single bout of exercise with a flexible pole induces significant cardiac autonomic responses in healthy men
    (Faculdade de Medicina / USP, 2014-09-01) Ogata, Cristiane Mayumi [UNIFESP]; Navega, Marcelo Tavella; Abreu, Luiz Carlos de; Ferreira, Celso [UNIFESP]; Cardoso, Marco A.; Raimundo, Rodrigo Daminello; Ribeiro, Vivian L. [UNIFESP]; Valenti, Vitor Engrácia [UNIFESP]; Universidade Estadual Paulista (UNESP); Santo André; SP; Faculdade de Medicina do ABC Departamento de Morfologia e Fisiologia; São Paulo; Universidade Federal de São Paulo (UNIFESP)
    OBJECTIVES: Flexible poles can provide rapid eccentric and concentric muscle contractions. Muscle vibration is associated with a tonic vibration reflex” that is stimulated by a sequence of rapid muscle stretching, activation of the muscle spindles and stimulation of a response that is similar to the myotatic reflex. Literature studies analyzing the acute cardiovascular responses to different exercises performed with this instrument are lacking. We investigated the acute effects of exercise with flexible poles on the heart period in healthy men.METHOD: The study was performed on ten young adult males between 18 and 25 years old. We evaluated the heart rate variability in the time and frequency domains. The subjects remained at rest for 10 min. After the rest period, the volunteers performed the exercises with the flexible poles. Immediately after the exercise protocol, the volunteers remained seated at rest for 30 min and their heart rate variability was analyzed.RESULTS: The pNN50 was reduced at 5-10 and 15-20 min after exercise compared to 25-30 min after exercise (p = 0.0019), the SDNN was increased at 25-30 min after exercise compared to at rest and 0-10 min after exercise (p = 0.0073) and the RMSSD was increased at 25-30 min after exercise compared to 5-15 min after exercise (p = 0.0043). The LF in absolute units was increased at 25-30 min after exercise compared to 5-20 min after exercise (p = 0.0184).CONCLUSION: A single bout of exercise with a flexible pole reduced the heart rate variability and parasympathetic recovery was observed approximately 30 min after exercise.