autonomic nervous system

IJCS

Original Article

Impact of Air Pollutant on Heart Rate Variability in Healthy Young Adults

Anita de Cássia Melinski et al. Aparecida Maria Catai Sílvia Cristina Garcia de Moura Juliana Cristina Milan-Mattos Monica Yuri Takito

Abstract

Background:

Air pollution and sex independently affect cardiac autonomic control, which can be assessed by heart rate variability (HRV). The research hypothesis is that individuals exposed to low concentrations of pollution have higher cardiac autonomic modulation compared to those exposed to high concentrations and that women have better cardiac autonomic control than men.

Objective:

To analyze the impact of exposure to air pollutants, specifically smoke, and sex on HRV in healthy young people exposed to different concentrations of pollution over an average period of 22 years.

Methods:

From April to September 2011, 36 participants of both sexes (20-30 years old) were selected, grouped by levels of air pollution exposure according to indices provided by the Environmental Company of São Paulo State. The R-R intervals (R-Ri) of the electrocardiogram were captured using a heart rate monitor during supine rest. HRV was analyzed by spectral analysis and conditional entropy. The Queen’s College step test was used to characterize functional capacity. A between-group comparison was performed using the two-way ANOVA statistical test (post hoc Tukey) and p<0.05.

Results:

Significant differences were found in mean R-Ri (p<0.01) and cardiac parasympathetic modulation between sexes in the same city (p=0.02) and between groups exposed to different air pollution concentrations (p<0.01).

Conclusion:

Our results suggest that long-term exposure to air pollutants, specifically smoke, has an unfavorable impact on HRV, with reduced cardiac vagal autonomic modulation in healthy young adults, especially females.

Ler artigo completo

IJCS

Original Article

Association of Anti-β1 and Anti-M2 Antibodies with Autonomic Nervous System Modulation in Patients with Chronic Chagas Cardiomyopathy

Delma Maria Cunha et al. Pedro Cunha Tzirulnik Patricia Cristina dos Santos Costa Danton Machado Cunha Ademir Batista da Cunha

Abstract

Background:

Different immune mechanisms of myocardial damage involved in the pathophysiology of Chagas disease coexist with high titers of autoantibodies induced by T. cruzi . There are few studies in the literature about the adaptive role of anti-β1 and anti-M2 antibodies in chronic Chagas cardiomyopathy (CCC).

Objectives:

To evaluate the association between anti-β1 and anti-M2 antibodies with heart rate variability (HRV) parameters on 24h Holter monitoring and the rate-pressure product (RPP) on cardiopulmonary exercise testing (CPET).

Methods:

Anti-β1 and anti-M2 antibody titers were measured by enzyme-linked immunosorbent assay (ELISA) in 64 patients affected by CCC. Analysis of HRV was performed through the time-domain indices NNs, mean NN, SDNN, SDANN, SDNN index, NNNs, RMSSD, and pNN50. Spearman’s correlation coefficient was used to assess the association between antibody titers and numerical variables. The Mann–Whitney test was used for comparison between two groups. Multiple linear regression was used to identify independent variables capable of explaining anti-β1 and anti-M2 antibody titers at the 5% significance level.

Results:

On 24h Holter, during the period of greatest parasympathetic activation (2:00-6:00 a.m.), an inverse association was found between anti-β1 titers and SDNN (r_s=-0.13, p =0.041, n=43), as well as a direct association between anti-M2 titers and SDANN ( r _s=0.317, p =0.039, n=43). Regarding CPET variables, anti-β1 titers were directly associated with RPP (r_s=0.371, p =0.005, n=56). The subgroup of patients with a normal chronotropic response showed higher anti-β1 titers than the subgroup with an impaired response (p=0.023). RPP was an independent explanatory variable for anti-β1 titers, although with a low coefficient of determination (R²=0.147).

Conclusion:

The findings of this study suggest that, in patients with CCC, anti-β1 and anti-M2 antibodies may affect HRV parameters. RPP was directly associated with higher anti-β1 titers.

Ler artigo completo

IJCS

Review Article

Autonomic Innervation Evaluation in Cardiac Disease

Adriana Xavier de Brito et al. Adriana Glavam Ana Inês Bronchtein Paulo Henrique Rosado-de-Castro

Abstract

Cardiovascular diseases are among the leading causes of mortality and morbidity in the world. In different cardiac diseases, the neuronal function of the heart is impaired. Nevertheless, the development of a simple method to assess the autonomic effects on the heart and/or autonomic dysfunction is a challenge. The evaluation of autonomic innervation in cardiac diseases has helped to improve the knowledge of the pathophysiology of these conditions, as well as to provide information on their prognosis. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are currently the only imaging methods that allow in vivo assessment of cardiac innervation. The majority of SPECT and PET radiotracers evaluate sympathetic neuronal integrity using presynaptic imaging agents that are either labeled as endogenous transmitters or analogues. Postsynaptic imaging agents have also been developed to study sympathetic neuronal integrity, as well as tracers to investigate the parasympathetic nervous system. These methods may be used to analyze the innervation of the heart and allow for early detection of abnormalities caused by, for example, ischemia, heart failure, cardiomyopathies, cardiotoxicity, and arrhythmogenic disorders. This review provides an overview of cardiac innervation evaluation and their application in the assessment of heart disease.

Ler artigo completo

IJCS

Case Report

Linear and Nonlinear Heart Rate Variability Analysis in Gonadal Dysgenesis (Swyer Syndrome): A Case Report

Valdelias Xavier Pereira et al. Tatiana Dias de Carvalho Marcos Antonio Marinovic Junior Alex Rey Norberto … José Maria Soares Júnior Vitor Engrácia Valenti Isabel Cristina Esposito Sorpreso

Abstract

Swyer syndrome is one of the disorders of sexual differentiation. Previous studies have demonstrated increased sympathetic activity with heart rate variability (HRV) analysis with decreasing estradiol levels. One patient presented a pure 46, XY gonadal dysgenesis with female phenotype. Cardiac autonomic modulation was assessed through HRV analysis while at rest. This research analyzed linear and nonlinear indexes. HRV analysis showed reduced parasympathetic and global modulation with an apparent increase in sympathetic tone and a loss of HR fractal dynamics toward correlated behavior, characterized by low entropy and high determinism of time series.

Ler artigo completo

IJCS

Brief Communication

Acute Effect of Resistance Exercise on Mucociliary Clearance in Active Smokers

Alessandra Mayumi Marques Masuda et al. Iara Buriola Trevisan Tamara dos Santos Gouveia Guilherme Yassuyuki Tacao … Ercy Mara Cipulo Ramos Dionei Ramos

Abstract

Background:

Nasal mucociliary clearance (NMC) responds to autonomic activity through exercise. However, there is a gap in the literature on how NMC responds to resistance exercise.

Objective:

To evaluate the acute effects of resistance tube exercise on NMC and the autonomic nervous system in smokers.

Methods:

Clinical trial was performed with 18 individuals. Personal, anthropometric, and smoking history data were collected, and a pulmonary function test was performed by spirometry. The fatigue resistance test was performed in order to obtain the number of repetitions for the prescription of exercise. Heart rate variability was captured using a monitor. Subsequently, the exhaled carbon monoxide (exCO) was measured and a saccharin transit test (STT) was performed for NMC.

Results:

The non-smoking group presented a significant decrease of 4.0±3.2 minutes in STT after P1 (p=0.021). Regarding HRV, the smoking group presented a significant decrease of mean RR (−90.3±53.0; p=0.011), SDNN (−560.0±1333.2; p=0.008), RMSSD (−13.6±10.5; p=0.011), LFms² (−567.3±836.1; p=0.008), HFms² (−223.8±231.8; p=0.008), SD1 (−9.7±7.4; p=0.011) and SD2 (−20.7±17.0; p=0.008), and an increase of mean HR (10.2±5.9; p=0.011) after P2. In the non-smoking group, a significant decrease was observed in the mean RR (−67.1±70.7; p=0.038), SDNN (−16.8±15.0; p=0.015), RMSSD (−12.3±14.7; p=0.011), LFms² (−831.2±1347.5; p=0.015), SD1 (−8.7±10.4; p=0.011), and SD2 (−22.0±19.1; p=0.015), while an increase in HR (7.1±7.3; p=0.028) was found after P1.

Conclusions:

The intensity of the resistance exercise applied to the patient was not enough to promote changes in smokers. By contrast, in non-smokers, the same intensity of exercise was effective in promoting alterations in the NMC and autonomic activity. (Int J Cardiovasc Sci. 2021; 34(2):223-230)

Ler artigo completo

IJCS

Original Article

Evaluation of the Autonomic Nervous System in Chronic Chagasic Cardiopathy: A Systematic Review of the Literature

Lorena dos Santos Marreto Rimolo et al. Roberto Magalhães Saraiva Ademir Batista da Cunha

Abstract

Background

The importance of regional sympathetic denervation in the pathophysiology and prognosis of Chagas disease has been recognized.

Objective

To conduct a review of studies that have assessed dysautonomia in chronic Chagas heart disease.

Methods

The search was performed on the Medline, Pubmed, Lilacs and SciELO databases. The inclusion criteria were: original articles published in full; studies on individuals with Chagas disease, that used diagnostic methods for chagasic cardiomyopathy, and had clear inclusion and exclusion criteria. Duplicate studies, studies including children (0 to 10 years old), studies involving animals, in vitro experiments, case reports, editorials, theses, and dissertations were excluded.

Results

A total of 281 articles were retrieved, and 10 met the inclusion criteria and were analyzed. There was great heterogeneity as to the technique for assessing dysautonomia, groups of patients studied and classification of Chagas disease. The methods used for studying the autonomic system was immunohistochemistry (n=1), Valsalva and tilt-test (n=1), scintigraphy (n=6) and Holter monitoring (n=2). The results indicated dysautonomia in the indeterminate, digestive and cardiac forms of Chagas disease, and sympathetic denervation in the indeterminate and cardiac forms of the disease. There was agreement between areas of denervation, hypoperfusion and fibrosis, but areas of denervation were larger than those of hypoperfusion. The frequency of denervation and its extension increased from the indeterminate to the cardiac form. There was an association between extension of denervation and previous history of malignant ventricular arrhythmia.

Conclusions

The evidence presented in this review supports that an early diagnosis of autonomic denervation in chronic Chagas’ disease allows the identification of patients with an increased risk of sudden death. Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0

Ler artigo completo

IJCS

Original Article

Cardiac Autonomic Modulation of Healthy Individuals and Patients with Chronic Obstructive Pulmonary Disease During Spontaneous and Controlled Breathing

Mario Augusto Paschoal et al. Livea Gianfrancesco Luisa Torres Camargo Náira Bueno Seixas Ana Beatriz Paschoal

Abstract

Background:

Lung diseases and different forms of breathing may interfere with cardiac autonomic modulation (CAM).

Objective:

To compare CAM in individuals with chronic obstructive pulmonary disease (COPD) with healthy individuals during spontaneous breathing (SB) and controlled breathing (CB).

Methods:

Cross-sectional study involving 30 individuals selected by convenience, divided into COPD group (n = 19) and control group (CG; n = 12). All participants were submitted to heart beat recordings during five minutes at rest (SB) and another five minutes during CB performed at six cycles/min. CAM was made by assessment of the heart rate variability (HRV) through time domain (TD) and frequency domain (FD). Comparisons between groups were performed by Mann Whitney test, and significance level was set at p < 0.05.

Results:

During SB, HRV TD and FD indices were higher in the controls than in the COPD group, respectively – RR intervals (53.2 ms versus 36.6 ms), RMSSD (42.1 ms versus 26.6 ms) (p < 0.05), total power (28322.8 ms²/Hz versus 2011.6 ms²/Hz), and high-frequency band (800.5 ms⁽²⁾ versus 330.7 ms²). During CB, the CG also showed higher values for the TD parameters pNN50 (11.7% versus 5.1%), RMSSD (48.3 ms versus 26.7 ms), and SD of RRi (64.9 ms versus 44.7 ms), as well as for the low-frequency component of FD analysis (2848.6 ms² versus 1197.9 ms²).

Conclusion:

COPD patients have different CAM when compared with healthy individuals during spontaneous (SB) and controlled breathing (CB).

Ler artigo completo

IJCS

Review Article

Effects of Exercise Training on Cardiovascular and Autonomic Parameters in Stroke Survivors: A Systematic Review

Bruno Bavaresco Gambassi et al. Fabiano de Jesus Furtado Almeida Ana Eugênia Araújo Furtado Almeida João Alberto Ribeiro … Tânia Maria Gaspar Novais Paulo Adriano Schwingel Ciro Oliveira Queiroz Clarcson Plácido Conceição dos Santos Bruno Rodrigues

Abstract

Negative changes in cardiovascular and autonomic variables in stroke survivors have encouraged the global scientific community to focus on investigating therapeutic strategies to mitigate stroke damage. The objective of the present study was to describe the effects of exercise training on cardiovascular and autonomic variables in stroke survivors. We used the PICO (population, intervention, control/comparison, and outcome variables) model for the search of articles in PubMed and Physiotherapy Evidence Databases from 2009 to December 2018. The following data were also recorded: type of study, author, year of publication, participants (time after stroke, sample size, and age) and benefits of exercise training. A total of 544 articles were initially selected, of which nine peer-reviewed articles met the search criteria. These nine studies enrolled 611 participants (middle-aged or elderly), and pointed to positive effects of training on maximal oxygen uptake, peak aerobic capacity, 6-minute walk test and resting heart rate. However, more well-controlled studies are needed to confirm the benefits of exercise training on cardiovascular and autonomic variables in this population.

Ler artigo completo

ABC

Original Article

Cholinergic stimulation with pyridostigmine, hemodynamic and echocardiographic analysis in healthy subjects

Paulo Vasconcellos de Pontes et al. Bianca Gouveia Bastos Luiz José Martins Romêo F° Evandro Tinoco Mesquita Antonio Claudio Lucas da Nóbrega

OBJECTIVE: Growing evidence suggests that sudden death after an acute myocardial infarction (AMI) correlates with autonomic nervous system imbalance. Parasympathomimetic drugs have been tested to reverse these changes. However, their effects on ventricular function need specific evaluation. Our objective was to analyze pyridostigmine’s (PYR) effect on hemodynamic and echocardiographic variables of ventricular function. METHODS: Twenty healthy volunteers underwent Doppler echocardiographic evaluations, blood pressure (BP), and heart rate (HR) assessment at rest, before and 120 min after ingestion of 30 mg PYR or placebo, according to a double-blind, placebo-controlled, crossed and randomized protocol, on different days. RESULTS: PYR was well tolerated and did not cause alterations in BP or in ventricular systolic function. A reduction in HR of 10.9±1.3% occurred (p<0,00001). There was an A wave reduction in the mitral flow (p<0.01) and an E/A ratio increase (p0.05). CONCLUSION: PYR reduces HR and increases E/A ratio, without hemodynamic impairment or ventricular function change.

Ler artigo completo

ABC

Original Article

Exercise stress testing in healthy subjects during cholinergic stimulation after a single dose of pyridostigmine

Salvador M. Serra et al. Ricardo Vivacqua C. Costa Bianca Gouvêa Bastos Kelb Bousquet Santos … Sérgio Henrique Rodolpho Ramalho Antonio Claudio Lucas da Nóbrega

OBJETIVE: The evaluation, by exercise stress testing, of the cardiorespiratory effects of pyridostigmine (PYR), a reversible acetylcholinesterase inhibitor. METHODS: A double-blind, randomized, cross-over, placebo-controlled comparison of hemodynamic and ventilation variables of 10 healthy subjects who underwent three exercise stress tests (the first for adaptation and determination of tolerance to exercise, the other two after administration of placebo or 45mg of PYR). RESULTS: Heart rate at rest was: 68±3 vs 68±3bpm before and after placebo, respectively (P=0.38); 70±2 vs 59±2bpm, before and after pyridostigmine, respectively (P<0.01). During exercise, relative to placebo: a significantly lower heart rate after PYR at, respectively, 20% (P=0.02), 40% (P=0.03), 80% (P=0.05) and 100% (P=0.02) of peak effort was observed. No significant differences were observed in arterial blood pressure, oxygen consumption at submaximal and maximal effort, exercise duration, respiratory ratio, CO2 production, ventilation threshold, minute ventilation, and oxygen pulse. CONCLUSION: Pyridostigmine, at a dose of 45mg, decreases heart rate at rest and during exercise, with minimal side effects and without interfering with exercise tolerance and ventilation variables.

Ler artigo completo

ABC

Original Article

Reduction of QTc interval dispersion. Potential mechanism of cardiac protection of pyridostigmine bromide

Renata Rodrigues Teixeira de Castro et al. Salvador Manoel Serra Antonio Claudio Lucas da Nóbrega

OBJECTIVE: Parasympathetic dysfunction is an independent risk factor in individuals with coronary artery disease, and cholinergic stimulation is a potential therapeutical option. We determined the effects of pyridostigmine bromide, a reversible anticholinesterase agent, on electrocardiographic variables of healthy individuals. METHODS: We carried out a cross-sectional, double blind, randomized, placebo-controlled study. We obtained electrocardiographic tracings in 12 simultaneous leads of 10 healthy young individuals at rest before and after oral administration of 45 mg of pyridostigmine or placebo. RESULTS: Pyridostigmine increased RR intervals (before: 886±27 ms vs after: 1054±37 ms) and decreased QTc dispersion (before: 72±9ms vs after: 45±3ms), without changing other electrocardiographic variables (PR segment, QT interval, QTc, and QT dispersion). CONCLUSION: Bradycardia and the reduction in QTc dispersion induced by pyridostigmine may effectively represent a protective mechanism if these results can be reproduced in individuals with cardiovascular diseases.

Ler artigo completo