scholarly journals Effects of chronic exposure to usual and high doses of Bisphenol A on cardiac arrhythmias, electrophysiology, and autonomic modulation

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
A Scridon ◽  
A I Balan ◽  
V B Halatiu ◽  
B A Finascu ◽  
D A Cozac ◽  
...  
Keyword(s):  
Heart Rate ◽  
Bisphenol A ◽  
Action Potential ◽  
Cardiac Arrhythmias ◽  
Chronic Exposure ◽  
Ventricular Arrhythmias ◽  
Human Exposure ◽  
High Dose ◽  
Autonomic Modulation ◽  
Premature Beats

Abstract Background Bisphenol A (BPA) is a synthetic compound found in plastic bottles, sports equipment, or water pipes. The continuous and inevitable human exposure to BPA has been related to increased cardiovascular risk. In experimental studies, acute exposure to high BPA doses was associated with ventricular arrhythmias. However, the effects of chronic exposure to usual BPA doses (i.e., relevant for usual human exposure) on cardiac arrhythmogenicity have not been properly assessed. Purpose We aimed to assess the effects of chronic exposure to high and usual BPA doses on cardiac arrhythmias, electrophysiology, and autonomic modulation in rats. Methods Adult female Wistar rats were randomized into 3 groups: Control, BPA, and BPA-HD (n=7 each). BPA and BPA-HD rats received 50 μg/kg/day and 25 mg/kg/day of BPA, respectively, for 9 weeks. Rats were implanted with radiotelemetry ECG devices and 24-h ECG recordings were performed prior to and after application of transesophageal atrial burst pacing (4,000 stimuli/min for 20 s; 15 cycles). Heart rate variability (HRV) parameters and atrial and ventricular arrhythmias (i.e., atrial premature beats [APB], atrial fibrillation [AF], ventricular premature beats [VPB], ventricular tachycardia/fibrillation [VT/VF]) were assessed based on the 24-h ECG recordings. The left atrium was then collected and atrial depolarization velocity and action potential duration to 90% (APD90) and 50% (APD50) of complete repolarization were measured. Results Mean heart rate (p=0.48), the number of VPB (p=0.90), AF inducibility (p=0.68), and atrial action potential parameters (all p>0.05) were all similar between the 3 groups. None of the animals presented VT/VF. There was no significant difference in the number of atrial or ventricular arrhythmic events nor in the HRV parameters between BPA and Control (all p>0.05). However, BPA-HD presented a significantly higher number of APB both prior to (p=0.02) and after (p=0.04) atrial pacing, and a significantly higher number of post-pacing spontaneous AF episodes (p<0.01) compared to Control. The parasympathetic indexes SDNN, RMSSD, pNN5, and the NHF of the HRV spectrum were all significantly higher (all p<0.05), whereas the LF/HF ratio, an index of sympathetic and parasympathetic interactions, was significantly lower (p=0.01) in the BPA-HD compared with the Control rats. Conclusions In rats, chronic exposure to BPA doses relevant for usual human exposure was not associated in any significant change in cardiac arrhythmogenicity, electrophysiology, or autonomic modulation. However, high-dose BPA exposure, such as that occurring in workers in the plastics industry, led to significant increase in atrial arrhythmogenicity, including AF, that did not seem to be related to atrial electrophysiology changes. Instead, given the strong atrial proarrhythmic effects of vagal hyperactivity, this effect could be linked to the significant increase in vagal modulation induced by high-dose BPA exposure. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS – UEFISCDI

Antiarrhythmic Properties of Acetaminophen in the Dog

2007 ◽  
Vol 232 (9) ◽  
pp. 1245-1252 ◽  
Author(s):  
Gary F. Merrill ◽  
Jared H. Merrill ◽  
Roseli Golfetti ◽  
Kathryn M. Jaques ◽  
Norell S. Hadzimichalis ◽  
...  
Keyword(s):  
Heart Rate ◽  
Ventricular Arrhythmias ◽  
Left Ventricular ◽  
High Dose ◽  
Treatment Groups ◽  
Arterial Blood ◽  
Regional Myocardial Ischemia ◽  
Ectopic Beats ◽  
Premature Beats ◽  
Antiarrhythmic Effects

Mongrel dogs bred for research and weighing 25 ± 3 kg were used to test the hypothesis that acetaminophen has antiar-rhythmic properties. Only ventricular arrhythmias defined by the Lambeth Conventions were investigated. Dogs were exposed either to 60 mins of regional myocardial ischemia followed by 180 mins of reperfusion ( n = 14) or were administered a high dose of ouabain ( n = 14). Both groups of 14 dogs were further divided into vehicle and acetaminophen treatment groups ( n = 7 in each). During selected 10-min intervals, we recorded the numbers of ventricular premature beats, ventricular salvos, ventricular bigeminy, ventricular tachycardia (nonsustained and sustained), and we recorded the heart rate, systemic arterial blood pressure, and left ventricular function. Neither heart rate nor the number of ventricular arrhythmias differed significantly under baseline conditions. Conversely, the combined average number of ventricular ectopic beats during ischemia and reperfusion was significantly less in the presence of acetaminophen (28 ± 4 vs. 6 ± 1; P < 0.05). Similarly, percent ectopy during reperfusion in vehicle- and acetaminophen-treated dogs was 1.4 ± 0.4 and 0.4 ± 0.2, respectively ( P < 0.05). The number of all ventricular ectopic beats except ventricular salvos was also significantly reduced in the presence of acetaminophen. Similar results were obtained with ouabain. Our results reveal that systemic administration of a therapeutic dose of acetaminophen has previously unreported antiarrhythmic effects in the dog.

scholarly journals Chronic Exposure to High Doses of Bisphenol A Exhibits Significant Atrial Proarrhythmic Effects in Healthy Adult Rats

2021 ◽  
Vol 31 (3) ◽  
pp. 587-595
Author(s):  
Vasile Bogdan HALATIU ◽  
◽  
Alkora Ioana BALAN ◽  
Dan Alexandru COZAC ◽  
Remus BOBARNAC ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Chronic Exposure ◽  
Atrial Pacing ◽  
Autonomic Tone ◽  
Adult Rats ◽  
Female Wistar Rats ◽  
High Doses ◽  
Premature Beats

Objectives: We aimed to evaluate the effects of chronic exposure to bisphenol A (BPA) on atrial fibrillation (AF) occurrence in rats. Methods: Twenty-two healthy female Wistar rats were randomized into three groups: Control (no BPA; n=7), BPA (exposed to usual BPA doses; 50 μg/kg/day, 9 weeks; n=7), and hBPA (exposed to high BPA doses; 25 mg/kg/day, 9 weeks; n=8). 24-h ECG monitoring was performed using radiotelemetry ECG devices prior to and after transesophageal atrial pacing. Spontaneous and pacing-induced atrial arrhythmias, autonomic tone, and in vivo an in vitro atrial arrhythmogenicity-related parameters were evaluated. Results: All studied parameters were similar between Control and BPA (all p>0.05). However, compared to Control, hBPA presented more atrial premature beats both at baseline (p=0.04) and after pacing (p=0.03), more AF episodes (p<0.001) and of longer duration (p=0.02) following transesophageal stimulation, and significantly higher vagal tone (all p<0.05). Conclusions: Chronic exposure to high, but not usual BPA doses induced significant atrial proarrhythmic effects in healthy rats, and this may be at least partially due to BPA-induced vagal hyperactivation. Exposure to high BPA doses, such as that occurring in plastics industry workers, could favor AF occurrence even in the absence of underlying cardiovascular disease.

scholarly journals Candidalysin impedes the development of embryonic zebrafish (Danio rerio)

2021 ◽  
Author(s):  
Jing Shen ◽  
JingCong Tan ◽  
Haochun Shi ◽  
Jie Zhou ◽  
Yanbin Zhao ◽  
...  
Keyword(s):  
Heart Rate ◽  
Fungal Pathogen ◽  
Chronic Exposure ◽  
Low Dose ◽  
Aquatic Organisms ◽  
High Dose ◽  
Hatching Rate ◽  
Human Fungal Pathogen ◽  
Developmental Effects ◽  
First Time

Abstract Candidalysin is a cytolytic peptide secreted by Candida albicans, an opportunistic human fungal pathogen that was widely spread in clinic and in the environment. However, its impacts on the development of aquatic organisms remain limited. Herein, we explored the developmental effects of candidalysin on embryonic zebrafish at concentrations from 0.008 to 160 mg/L. In acute exposure, decreased survival rate with EC50 at 49.5 mg/L were observed. Meanwhile, in high-dose exposure groups (5-160 mg/L), an increased swimming frequency were observed at candidalysin concentrations of 10 mg/L and above. In chronic exposure, decreased spontaneous contraction, hatching rate and heart rate were identified in low-dose exposure groups (0.008-5 mg/L). Especially for the heart rate, significant changes were observed at candidalysin concentrations as low as 0.008 mg/L (environmentally relevant). The present study first time pointed out the developmental toxicities of candidalysin on fish that was rarely investigated, and thus contributed to its environmental risk assessment.

Calcium-dependent arrhythmias in transgenic mice with heart failure

2003 ◽  
Vol 284 (2) ◽  
pp. H431-H441 ◽  
Author(s):  
Barry London ◽  
Linda C. Baker ◽  
Joon S. Lee ◽  
Vladimir Shusterman ◽  
Bum-Rak Choi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Transgenic Mice ◽  
Action Potential ◽  
Ventricular Arrhythmias ◽  
Calcium Dependent ◽  
Tnf Α ◽  
Cytokine Tumor Necrosis Factor ◽  
Premature Beats ◽  
Heart Failure Model

Transgenic mice overexpressing the inflammatory cytokine tumor necrosis factor (TNF)-α (TNF-α mice) in the heart develop a progressive heart failure syndrome characterized by biventricular dilatation, decreased ejection fraction, atrial and ventricular arrhythmias on ambulatory telemetry monitoring, and decreased survival compared with nontransgenic littermates. Programmed stimulation in vitro with single extra beats elicits reentrant ventricular arrhythmias in TNF-α ( n = 12 of 13 hearts) but not in control hearts. We performed optical mapping of voltage and Ca2+ in isolated perfused ventricles of TNF-α mice to study the mechanisms that lead to the initiation and maintenance of the arrhythmias. When compared with controls, hearts from TNF-α mice have prolonged of action potential durations (action potential duration at 90% repolarization: 23 ± 2 ms, n = 7, vs. 18 ± 1 ms, n = 5; P < 0.05), no increased dispersion of refractoriness between apex and base, elevated diastolic and depressed systolic [Ca2+], and prolonged Ca2+ transients (72 ± 6 ms, n = 10, vs. 54 ± 5 ms, n = 8; P < 0.01). Premature beats have diminished action potential amplitudes and conduct in a slow, heterogeneous manner. Lowering extracellular [Ca2+] normalizes conduction and prevents inducible arrhythmias. Thus both action potential prolongation and abnormal Ca2+ handling may contribute to the initiation of reentrant arrhythmias in this heart failure model by mechanisms distinct from enhanced dispersion of refractoriness or triggered activity.

Low-dose steroid-induced bradyarrhythmias and treatment refractory hypokalaemia: a case report

2020 ◽  
pp. 1-3 ◽  
Author(s):  
Arindam Ghosh ◽  
Saba Annigeri ◽  
Anupama Nair
Keyword(s):  
Adverse Effect ◽  
Heart Rate ◽  
Cardiac Arrhythmias ◽  
Low Dose ◽  
High Dose ◽  
Methyl Prednisolone ◽  
Pulse Dose ◽  
Rapid Control ◽  
Treatment Refractory ◽  
Mineralocorticoid Activity

Abstract Corticosteroid therapy has become an important modality of treatment for diseases in which rapid control of immunoinflammatory processes is required. However, one of the serious, but less known adverse effect of this therapy is cardiac arrhythmias. This includes both tachyarrhythmias and bradyarrhythmias. Corticosteroid use may also be associated with electrolyte imbalances like hypokalaemia by its mineralocorticoid activity. Those side effects are mainly seen with high-dose intravenous methyl-prednisolone or oral pulse dose prednisolone therapy. Here we report our experience in a child with warm idiopathic autoimmune haemolytic anaemia who developed sinus bradyarrhythmias and treatment refractory hypokalaemia during low-dose steroid therapy with reduction in heart rate by 60% of baseline.

Efeito da manipulação vertebral sobre a modulação autonômica cardíaca

2016 ◽  
Vol 17 (5) ◽  
pp. 498
Author(s):  
Alyssa Conte Da Silva ◽  
Juliana Falcão Padilha ◽  
Jefferson Luiz Brum Marques ◽  
Cláudia Mirian De Godoy Marques
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Spinal Manipulation ◽  
Autonomic Modulation ◽  
Autonomic Nervous ◽  
Cardiac Autonomic Modulation

Introdução: Existem poucos estudos que evidenciam a manipulação vertebral relacionada à modulação autonômica cardíaca. Objetivo: Revisar a literatura sobre os efeitos da manipulação vertebral sobre a modulação autonômica cardíaca. Métodos: Foi realizada uma busca bibliográfica nas bases de dados da saúde Medline, Pubmed e Cinahl, no período correspondido entre setembro e novembro de 2014. Foram utilizados os descritores em inglês Spinal Manipulation, Cardiac Autonomic Modulation, Autonomic Nervous System, Heart Rate Variability, além de associações entre eles. Resultados: Foram encontrados 190 artigos, sendo excluídos 39 por serem repetidos, restando 151. Destes, 124 não se encaixaram nos critérios de inclusão e após leitura crítica e análise dos materiais foram selecionados 7 artigos. Grande parte dos estudos revelou que a manipulação da coluna, independente do segmento, demonstra alterações autonômicas, tanto em nível simpático quanto parassimpático. Conclusão: Existem diferentes metodologias para avaliação da modulação autonômica cardíaca, sendo a Variabilidade da Frequência cardíaca através do eletrocardiograma a mais utilizada. A manipulação vertebral exerceu influência, na maioria dos artigos, sobre a modulação autonômica cardíaca.Palavras-chave: manipulação da coluna, sistema nervoso autônomo, variabilidade da frequência cardíaca. 

Pre-emptive Analgesia for Postoperative Pain Relief in Children – Role of Paracetamol

2009 ◽  
pp. 9-16
Author(s):  
Rubina Yasmin ◽  
AKM Akhtaruzzaman ◽  
Paresh Chandra Sarker ◽  
Neaz Ahmed ◽  
Ranadhir Kumar Kundu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Postoperative Pain ◽  
Diclofenac Sodium ◽  
Total Duration ◽  
Pain Scale ◽  
Prospective Clinical Study ◽  
High Dose ◽  
Induction Of Anaesthesia

This prospective clinical study was carried out in the Dept. of Anaesthesia, Analgesia and Intensive Care Medicine, BSMMU, Dhaka, during the period of May 2003 to July 2003. The study was done to emphasize the importance of giving analgesics preemptively instead of waiting for the child to complain of pain and to produce smooth recovery after surgery by decreasing immediate postoperative pain in children by a simple, safe acceptable drug. The children scheduled for tonsillectomy under general anaesthesia were recruited in this study. The analgesic efficiency of rectal paracetamol in two doses, 25 mg/kg bodywt.(Gr-P25) and 50 mg/kg. bodywt. (Gr-P50) were compared with Diclofenac Sodium suppository 1mg/ kg body weight (Gr-D) given half an hour before induction of anaesthesia. Pain scoring was done by TPPPS (Toddler Pre-schooler postoperative pain scale). Heart rate and blood pressure were stable in Gr-P50 and Gr-D. Time of first demand of analgesic was delayed in Gr-P50 and Gr-D. Total paracetamol consumption in 24 hours was less in Gr-P50(181±14.25) and Gr-D (212±25) than Gr-P25(318± 26.39). Total duration of analgesia in Gr- P50 (657±9.94) mins. and in Gr- D(502±10.63) mins. and in Gr-P25(288±23.17) mins. Pre-emptive high dose rectal paracetamol appears to be more effective than diclofenac sodium suppository for postoperative analgesia in children undergoing tonsillectomy. Journal of BSA, Vol. 18, No. 1 & 2, 2005 p.9-16

Obesity does not Impair Ambulatory Cardiovascular and Autonomic Responses Post-exercise

2021 ◽  
Author(s):  
Gabriel Kolesny Tricot ◽  
Fabiula Isoton Isoton Novelli ◽  
Lucieli Teresa Cambri
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Diastolic Blood Pressure ◽  
Maximal Exercise ◽  
Young Men ◽  
Autonomic Modulation ◽  
Incremental Test ◽  
Post Exercise ◽  
Cardiac Autonomic Modulation ◽  
Main Effect

AbstractThis study aimed to assess whether obesity and/or maximal exercise can change 24 h cardiac autonomic modulation and blood pressure in young men. Thirty-nine men (n: 20; 21.9±1.8 kg·m−2, and n: 19; 32.9±2.4 kg·m−2) were randomly assigned to perform a control (non-exercise) and an experimental day exercise (after maximal incremental test). Cardiac autonomic modulation was evaluated through frequency domain heart rate variability (HRV). Obesity did not impair the ambulatory HRV (p>0.05), however higher diastolic blood pressure during asleep time (p=0.02; group main effect) was observed. The 24 h and awake heart rate was higher on the experimental day (p<0.05; day main effect), regardless of obesity. Hypotension on the experimental day, compared to control day, was observed (p<0.05). Obesity indicators were significantly correlated with heart rate during asleep time (Rho=0.34 to 0.36) and with ambulatory blood pressure(r/Rho=0.32 to 0.53). Furthermore, the HRV threshold workload was significantly correlated with ambulatory heart rate (r/Rho=− 0.38 to−0.52). Finally, ambulatory HRV in obese young men was preserved; however, diastolic blood pressure was increased during asleep time. Maximal exercise caused heart rate increase and 24h hypotension, with decreased cardiac autonomic modulation in the first hour, regardless of obesity.

Low vagally-mediated heart rate variability and increased susceptibility to ventricular arrhythmias in rats bred for high anxiety

2014 ◽  
Vol 128 ◽  
pp. 16-25 ◽  
Author(s):  
Luca Carnevali ◽  
Mimosa Trombini ◽  
Gallia Graiani ◽  
Denise Madeddu ◽  
Federico Quaini ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Ventricular Arrhythmias ◽  
High Anxiety ◽  
Increased Susceptibility
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