Influence of Family History of Diabetes on Cardiac Autonomic Dysfunction of Adolescents

Abstract Background To evaluate cardiac autonomic modulation of adolescents with a family history of diabetic parents. Objective This study aims to evaluate the influence of a family history of diabetes on cardiac autonomic modulation. Methods This is an analytical and cross-sectional study on adolescents between 11 and 18 years of age, of both genders, who were divided into group with a family history of diabetes and a control group without a family history of diabetes. The study protocol consisted of the analysis of heart rate variability, blood pressure, anthropometric measurements, and body composition. Also, by using questionnaires, level of physical activity, sexual maturation, and sleep quality were evaluated. Normality of data distribution was tested using the Kolmogorov-Smirnov test. Then, statistical significance was evaluated using the Student's t-test, and the Cohen's teste was used for calculation of the effect size. The level of significance adopted in the statistical analysis was 5%. Results When the group of individuals with a family history of diabetes was compared with the control group, statistically significant differences were observed in the variables the standard deviation of the NN time series interval (SDNN) (43.9 ± 2.2 vs. 53.5 ± 2.6 ms), the square root of the quadratic differences (RMSSD) (41.9 ± 3.3 vs. 52.4 ± 3.2 ms), standard deviation of beat-to-beat instantaneous variability (SD1) (29.7 ± 2.3 vs. 37.1 ± 2.3 ms), long-term standard deviation of continuous RR intervals (SD2) (. 54.1 ± 2.6 vs. 66.66 ± 3.5 ms), and in low frequency (LF) (496.0 ± 49.5 vs. 728 ± 71.6 ms2) and high frequency (HF) (1050.0 ± 120.4 vs. 737.4 ± 98.5 ms2) in the frequency domain. Conclusions Global autonomic modulation is decreased in adolescents with a family history of diabetes. We also observed a decrease in vagal activity in this group. So, sympathetic autonomic modulation is predominant in this population. (Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0)

Autonomic cardiac and cardiorespiratory responses in volleyball athletes compared torecreationally trained individuals / Respostas autonômicas cardíacas e cardiorespiratória deatletas de volleyball comparados a indivíduos treinadorecreacionalmente

The aim of this study was to investigate the autonomic cardiac modulation between professional volleyball players (VP) and recreational aerobically trained individuals (RAT). Methods: Twenty eight men were divided into two groups, (VP; n = 14) and (RAT; n = 14) and each group was subjected to a sub-maximal progressive ramp treadmill test. Cardiac cycle beat to beat (RR) intervals, was obtained through electrocardiogram recording with the test being stopped when the individual reached 85% of their maximum age-predicted heart rate (HR). The heart rate variables were calculated from ECG using MATLAB based algorithms. Results: At rest, RAT showed lower values of the mean value of RR interval, the root mean square successive difference of all RR intervals (r-MSSD), low frequency (LF) and total power spectral (TP) when compared to VP. No significant difference between groups was noted for high frequency (HF) and index LF/HF. After exercise, no significant differences were measured between groups. Mean values of VO2, VE/VO2, and VE showed no significant difference at rest and post effort. Conclusion:The variables such as frequency, intensity and volume may to interfere the autonomic cardiac modulation and possibly indicating a superior protection against exercise-induced ventricular arrhythmias and lower risk of sudden cardiac deaths...

O objetivo do presente estudo foi investigar o perfil da modulação autonômica cardíaca entre jogadores profissionais de voleibol (VP) e indivíduos aerobicamente treinados recreativas (RAT). Métodos: Vinte e oito homens foram divididos em dois grupos (VP; n = 14) e (RAT, n = 14). Cada grupo foi submetido a um teste ergométrico sub-máximo. O teste foi interrompido quando o indivíduo atingiu 85% da frequência cardíaca máxima baseada na idade (HR). Os intervalos R-R foram obtidos através da derivação V5 do eletrocardiograma de 12 derivações. As variáveis de domínio de tempo e frequência da variabilidade da freqüência cardíaca foram calculados utilizando algoritmos baseados em MATLAB. Resultados:Em repouso, RAT apresentaram valores signficativamente reduzidos de intervalo RR, RMSSD, potência espectral de baixa freqüência (LF) e potência espectral total (PT) em relação ao VP. Não houve diferença significativa inter-grupos para potência espectral de alta freqüência (HF) e índice LF/HF. Após o exercício, não foram observadas diferenças significativas inter-grupos. Os valores médios de VO2, VE/ VO2 e VE não apresentaram diferença significativa em repouso e pós esforço inter-grupos. Conclusão: As variáveis como a freqüência, intensidade e volume de treinamento pode interferir na modulação autonômica cardíaca e, possivelmente, indicando uma proteção contra arritmias ventriculares induzidas pelo exercício e menor risco de morte súbita cardíaca...

Preliminary Study About Effect of Continuous Positive Airway Pressure on Cardiac Autonomic Imbalance in Obstructive Sleep Apnea Syndrome

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is associated with cardiac arrhythmia due to autonomic dysfunction. The aim of this study was to elucidate the effect of OSAS on the QT interval and the efficacy of continuous positive airway pressure (CPAP) treatment on a prolonged QT interval. METHODS: From March 2007 to January 2008, 13 patients diagnosed as OSAS received CPAP treatment. Ten age- and sex-matched healthy controls were enrolled, and nighttime polysomnography was performed. We analyzed the full-night electrocardiogram.which is one of the elements of nighttime polysomnography.in all patients and controls. RESULTS: In the patient group, the QTc interval was 0.380+/-0.45 ms (mean+/-SD) before CPAP treatment and 0.368+/-0.32 ms during CPAP treatment. In the control group, the QTc interval was 0.348+/-0.26 ms. The QTc interval did not differ between OSAS patients and controls (p=0.143), but it did significantly shorten between before and after CPAP treatment (p=0.047). CONCLUSIONS: This study suggests that CPAP treatment can improve QTc prolongation and thereby prevent future ventricular arrhythmia.

Characteristics of Heart Rate Variability Among Adults with Metabolic Syndrome

OBJECTIVES: The authors tried to investigate the characteristics of Heart Rate Variability(HRV) among the subjects with metabolic syndrome for testing the possibility of clinical application of HRV in evaluating metabolic syndrome. METHODS: We examined the difference of the means of HRV between 122 subjects of metabolic syndrome and 1057 healthy controls using T-test, and the change of means in HRV according to increasing risk factors of metabolic syndrome. Using multiple regression analysis, we examined the association of HRV with the risk factors of metabolic syndrome. RESULTS: The HRV indices including SDNN(Standard Deviation of all normal NN intervals), RMSSD(the square Root of the Mean Squared Differences of successive all normal NN interval), TP(Total Power), LF(Low Freuency), and HF(High Frequency) were significantly lower in the metabolic syndrome group than in the normal control group, and the means of all HRV indices except LF/HF were decreased consistently according to increasing risk factors of metabolic syndrome. The fasting glucose, triglyceride, and waist circumference were dependent factors that contributed significantly to the change of HRV. CONCLUSION: These findings suggest metabolic syndrome adversely affects cardiac autonomic system and HRV could be a useful method for evaluating metabolic syndrome.

Efficácia das drogas antiarrítmicas. Proposta para uma nova forma de avaliação baseada nos efeitos farmacológicos horários / Antiarrhythmic drug effectiveness. Proposal for a new approach based on pharmacological hourly effects

PURPOSE--To use a new approach in order to assess the antiarrhythmic drugs, based in the hourly autonomic effects and antiarrhythmic efficacy of sotalol. METHODS--Sixteen patients were evaluated in a randomized double-blind placebo-controlled study. Patients were classified in group 1 (anti-arrhythmic efficacy) and group 2 (no antiarrhythmic efficacy). The following parameters were analyzed: 1) clinical variables as age, gender, cardiac disease and ventricular ectopies density; 2) drug effects on pNN50 in 24-hour and on mean hourly cardiac cycle length; 3) percentage of hourly ventricular ectopies distribution and its correlation with pNN50 and with mean hourly cardiac cycle length in all patients; 4) drug effects on mean hourly cardiac cycle length in groups 1 and 2; 5) correlation between hourly pNN50 and ventricular ectopies density after sotalol administration in groups 1 and 2; 6) hourly drug efficacy in groups 1 and 2 and correlation with pNN50. RESULTS--Efficacy of the drug was present in 8 (50) patients. Sotalol significantly increased 24-hour pNN50 (placebo 5.01 +/- 2.02; after drug, 11.70 +/- 5.59-p < 0.001), also increasing mean hourly cardiac cycle length during the day and night, in all patients (placebo 758.25 +/- 75.68 ms; after drug 967.71 +/- 80.17 ms-p < 0.000). It was noted that patients under placebo had different autonomic tonus; group 1 showed higher sympathetic activity as compared to group 2. Hourly drug efficacy was seen in 23 of 24-hour recordings in group 1 while it was not seen at any time in group 2. CONCLUSION--Sotalol significantly increased parasympathetic cardiac activity. The anti-arrhythmic response was related to the autonomic tonus seen before and after drug administration.