Short-term exposure to ambient ozone associated with cardiac arrhythmias in healthy adults

Objective The exact biological mechanism whereby exposure to ambient ozone(O3)may contribute to clinical onset of cardiovascular events remains unclear.In this study,we aim to examine the impacts of O3 exposure on cardiac arrhythmias and potential pathways involved through autonomic dysfunction and myocardial injury.Methods Seventy-three non-smoking healthy adults were followed with 4 repeated measurements of 24-hour ambulatory arrhythmias,heart rate variability,ST-segment deviation,and blood pressure(BP)in Beijing,China,2014‒2016.Generalized additive mixed models coupled with distributed lag nonlinear models were constructed to evaluate the associations and potential interlinks between O3 exposure and outcome measurements.Results During the study period,24-hour average concentrations of ambient O3 were 47.4µg/m3(ranging from 1.0 to 165.9µg/m3).Increased risks of premature ventricular contraction and ventricular tachycardia were associated with interquartile range increases in O3 exposure during the last 5 days before each participant's clinic visit,with relative risks of 2.14(95%confidence interval[CI]:1.95 to 2.32)and 5.47(95%CI:3.51 to 7.43),respectively.Mediation analyses further showed that sympathetic activation,parasympathetic inhibition,and elevated BP levels,as well as heightened risks of ST-segment depression could mediate up to 47.74%of the risks of arrhythmias attributable to O3 exposure.Conclusion Our results suggest that short-term exposure to ambient O3 could prompt the genesis of arrhythmias partially through worsening autonomic function and myocardial burden.

Cardiac arrhythmia and heart failure： From bench to bedside

Cardiac arrhythmia is an abnormal rate and/or rhythm of a heart due to its abnormal electrical impulse origination and/or propagation.Various etiologies can cause arrhythnuas.Heart failure(HF)is a clinical syndrome due to an impaired heart that can not pump sufficient blood to meet the systemic metabolic needs.The common causes of HF include myocardial infarction,hypertension,valvular heart disease,and cardiomyopathy.

Cardiac arrhythmias and cardiac arrest related to mushroom poisoning: A case report

BACKGROUND Mushroom exposure is a global health issue.The manifestations of mushroom poisoning (MP) may vary.Some species have been reported as rhabdomyolytic,hallucinogenic,or gastrointestinal poisons.Critical or even fatal MPs are mostly attributable to Amanita phalloides,with the development of severe liver or renal failure.Myocardial injury and even cases mimicking ST-segment elevation myocardial infarction (STEMI) have been previously reported,while cardiac arrhythmia or cardiac arrest is not commonly seen.CASE SUMMARY We report a 68-year-old woman with MP who suffered from delirium,seizure,long QT syndrome on electrocardiogram (ECG),severe cardiac arrhythmias of multiple origins,and cardiac arrest.She was intubated and put on blood perfusion.Her kidney and liver functions were intact;creatine kinase-MB was mildly elevated,and then fell within normal range during her hospital stay.We sent the mushrooms she left for translation elongation factor subunit 1α,ribosomal RNA gene sequence,and internal transcribed spacer sequence analyses.There were four kinds of mushrooms identified,two of which were found to be toxic.CONCLUSION This is the first time that we found cardiac toxicity caused by Panaeolus subbalteatus and Conocybe lactea,which were believed to be toxic to the liver,kidney,and brain.We suggest that intensive monitoring and ECG follow-up are essential to diagnose prolonged QT interval and different forms of tachycardia in MP patients,even without the development of severe liver or renal failure.The mechanisms need to be further investigated and clarified based on animal experiments and molecular signal pathways.

Cardiac arrhythmias detection in an ECG beat signal using fast fourier transform and artificial neural network

Cardiac Arrhythmias shows a condition of abnor-mal electrical activity in the heart which is a threat to humans. This paper presents a method to analyze electrocardiogram (ECG) signal, extract the fea-tures, for the classification of heart beats according to different arrhythmias. Data were obtained from 40 records of the MIT-BIH arrhythmia database (only one lead). Cardiac arrhythmias which are found are Tachycardia, Bradycardia, Supraventricular Tachycardia, Incomplete Bundle Branch Block, Bundle Branch Block, Ventricular Tachycardia. A learning dataset for the neural network was obtained from a twenty records set which were manually classified using MIT-BIH Arrhythmia Database Directory and docu- mentation, taking advantage of the professional experience of a cardiologist. Fast Fourier transforms are used to identify the peaks in the ECG signal and then Neural Networks are applied to identify the diseases. Levenberg Marquardt Back-Propagation algorithm is used to train the network. The results obtained have better efficiency then the previously proposed methods.

Amiodarone Therapy for Cardiac Arrhythmias: Is It Associated with the Development of Cancers?

Amiodarone is used worldwide to treat cardiac arrhythmias, as well as highly symptomatic cases of atrial fibrillation. With this expanded use, especially following its 1985 United States Food and Drug Administration approval, and its use as a long-term therapy in common practice, reports of cancers temporarily related to amiodarone have begun to increase. Animal studies, several clinical trials, numerous case reports, and a population-based cohort study have suggested that cancers may be associated with amiodarone use. This review focuses on the ever increasing evidence in the literature that suggests amiodarone therapy, especially with long-term use, may increase the potential risk of cancer development. It also expresses the need for more definitive studies to be conducted to provide clinicians with a clear answer to this important question.

Wenxin granule for cardiac arrhythmia: an overview of systematic reviews

目的:对稳心颗粒治疗心律失常的系统评价/meta分析进行再评价,为临床应用提供证据;分析目前研究中存在的问题,为研究者提供可能的优先研究主题。方法:从8 个数据库中检索稳心颗粒治疗心律失常的系统评价。分别用AMSTAR和GRADE评估系统评价的方法学质量和证据质量。结果:共纳入1 9 项系统评价,涉及52, 9 0 5 个参与者。AMSTAR评分3-10分,平均6 .5 分,中位数为6 分, 9 (9/19, 47.37°%)项系统评价的AMSTAR得分大于7 分,对其中的6 项研究采用GRADE评估其证据质量。结果显示,所有研究的证据质量都在极低和低之间,无中、高质量证存在。从结局指标报告来看,没有系统评价评估终点指标,虽然有部分研究报告了不良反应/事件,但很少有研究进行因果关系判断。系统评价结局指标矩阵显示,结局指标报告存在明显的异质性及不完全报告的情况,导致有些研究不能进行m eta分析。同时,一些原始研究由于结局指标报告不合理而被不能纳入系统评价(如未报告相关结局指标,治疗时间不合适/不清楚,数据不完全或无法提取)。结论:稳心颗粒治疗心律失常的疗效和安全性证据有限,未来需要更多的高质量R C T s和系统评价提供证据。在未来的研究中,有必要构建心律失常核心指标集,以提高结局指标报告水平,减少由于结局指标报告不合理而造成的浪费。

Expert Consensus on Wenxin Granule for Treatment of Cardiac Arrhythmias

INTRODUCTIONAntiarrhythmic drugs remain a critically important component of the approach to therapy of cardiac arrhythmias. Over the past 20 years, despite their antiarrhythmic efficacy in many pathological settings, Class Ⅰ and Ⅲ antiarrhythmic drugs have been shown to be associated with the development of proarrhythmias and an increase in the likelihood of causing higher mortality by inducing torsade de pointes ventricular tachycardia and other serious adverse reactions. Consequently, the development of safe and effective antiarrhythmic regimens remains a primary focus of contemporary cardiovascular research.

Nonalcoholic Fatty Liver Disease (NAFLD) and Risk of Cardiac Arrhythmias: A New Aspect of the Liver-heart Axis

Nonalcoholic fatty liver disease (NAFLD) is a pathologic condition frequently observed in clinical practice.To date,the prevalence of NAFLD is approximately 25-30% among adults of the general population in Western countries but increases to approximately 70-75% among patients with type 2 diabetes mellitus.In the last decade,accumulating evidence has clearly demonstrated that patients with NAFLD have not only an increased liver-related morbidity and mortality but also an increased risk of fatal and non-fatal cardiovascular events.In particular,several studies have documented the existence of an independent association among NAFLD and cardiac changes in structure and function in both non-diabetic and diabetic patients.In addition,mounting evidence also suggests that there is a strong relationship between NAFLD and cardiac arrhythmias,such as atrial fibrillation,QTc prolongation and ventricular arrhythmias.This is of clinical interest,as it could explain,at least in part,the increased risk of death for cardiovascular disease in patients with NAFLD.Therefore,seeing that cardiovascular disease complications are the leading cause of disability and death in NAFLD patients,the recent European clinical practice guidelines advised to check the cardiovascular system in all patients with NAFLD.This clinical mini review will briefly describe the increasing body of evidence regarding the association between NAFLD and cardiac arrhythmias,and discuss the potential biological mechanisms underlying this association.

Automatic Classification of Cardiac Arrhythmias Based on Hybrid Features and Decision Tree Algorithm

Accurate classification of cardiac arrhythmias is a crucial task because of the non-stationary nature of electrocardiogram(ECG)signals.In a life-threatening situation,an automated system is necessary for early detection of beat abnormalities in order to reduce the mortality rate.In this paper,we propose an automatic classification system of ECG beats based on the multi-domain features derived from the ECG signals.The experimental study was evaluated on ECG signals obtained from the MIT-BIH Arrhythmia Database.The feature set comprises eight empirical mode decomposition(EMD)based features,three features from variational mode decomposition(VMD)and four features from RR intervals.In total,15 features are ranked according to a ranker search approach and then used as input to the support vector machine(SVM)and C4.5 decision tree classifiers for classifying six types of arrhythmia beats.The proposed method achieved best result in C4.5 decision tree classifier with an accuracy of 98.89%compared to cubic-SVM classifier which achieved an accuracy of 95.35%only.Besides accuracy measures,all other parameters such as sensitivity(Se),specificity(Sp)and precision rates of 95.68%,99.28%and 95.8%was achieved better in C4.5 classifier.Also the computational time of 0.65 s with an error rate of 0.11 was achieved which is very less compared to SVM.The multi-domain based features with decision tree classifier obtained the best results in classifying cardiac arrhythmias hence the system could be used efficiently in clinical practices.

Conventional Acupuncture for Cardiac Arrhythmia：A Systematic Review of Randomized Controlled Trials

Objective：To exam the effect and safety of conventional acupuncture（CA） on cardiac arrhythmia.Methods：Nine medical databases were searched until February 2016 for randomized controlled trials.Heterogeneity was measured by Cochran Q test.Meta-analysis was conducted if I2 was less than 85% and the characteristics of included trials were similar.Results：Nine qualified studies involving 638 patients were included.Only 1 study had definitely low risk of bias,while 7 trials were rated as unclear and 1 as high.Meta-analysis of CA alone did not have a significant benefit on response rate compared to amiodarone in patients with atrial fibrillation（Af） and atrial flutter（AF） [relative risk（RR）：1.09;95% confidence interval（CI）：0.79–1.49;P=0.61;I2=61%,P=0.11].However,1 study with higher methodological quality detected a lower recurrence rate of Af in CA alone as compared with sham acupuncture plus no treatment,and benefits on ventricular rate and time of conversion to normal sinus rhythm were found in CA alone group by 1 study,as well as the response rate in CA plus deslanoside group by another study.Meta-analysis of CA plus anti-arrhythmia drug（AAD） was associated with a significant benefit on the response rate when compared with AAD alone in ventricular premature beat（VPB） patients（RR,1.19,95% CI：1.05–1.34;P=0.005;I2=13%,P=0.32）,and an improvement in quality-of-life score（QOLS） of VPB also showed in 1 individual study.Besides,a lower heart rate was detected in the CA alone group by 1 individual study when compared with no treatment in sinus tachycardia patients（MD –21.84 [–27.21,–16.47]） and lower adverse events of CA alone were reported than amiodarone.Conclusions：CA may be a useful and safe alternative or additive approach to AADs for cardiac arrhythmia,especially in VPB and Af patients,which mainly based on a pooled estimate and result from 1 study with higher methodological quality.However,we could not reach a robust conclusion due to low quality of overall evidence.

CARDIAC ARRHYTHMIA AFTER LUNG CANCER SURGERY －－ANALYSIS OF 140 PNEUMONECTTOMY CASES

Among 808 surgically resected lung cancer cases at Shanghai Chest Hospital during 1991 to 1992, 140 of them (17.3%) underwent Pneumonectomy. Of the 140 cases:124 male, 16 female; aged 27-74 yrs, 35.7% elder (60 and over), preoperative abnormal EKG was found in 38 cases, operative mortality was 4.3%. The histopathological diagnosis were: squamous 43.6%, adeno. 36.4%, small cell 8.6%, mixed type 11.4%. The pTNM stages: stage I 2.9%, II 17.1%, IIIa 55.0%, IIIb 21.4%, IV 3.6%.Postoperatively, arrhythmia occuried in 76 cases, with an incidence of 54.3%. Of the 76 arrhythmias, atrial fibrillation was seen in 7 patients, atrial premature beats in 2, supraventricular tachycardia in 1, and sinus tachycardia in 66. The incidences of cadiac arrhythmia during the postoperative day (DO), first day (D1), D2, D3,and D4 were 48.7%, 35.5%, 7.9%, 4.0%and 2.6%respectively. Conclusion: the cardiac arrhythmia is the most common complication after pneumonectomy for lung cancer surgery. The major causes were incisional pain, hypovolemia due to blood loss and respirative insufficiency due to anomia. The perioperative prevention and treatment for arrhythmia were also discussed.

Dysglycemia and arrhythmias

Disorders in glucose metabolism can be divided into three separate but interrelated domains,namely hyperglycemia,hypoglycemia,and glycemic variability.Intensive glycemic control in patients with diabetes might increase the risk of hypoglycemic incidents and glucose fluctuations.These three dysglycemic states occur not only amongst patients with diabetes,but are frequently present in other clinical settings,such as during critically ill.A growing body of evidence has focused on the relationships between these dysglycemic domains with cardiac arrhythmias,including supraventricular arrhythmias(primarily atrial fibrillation),ventricular arrhythmias(malignant ventricular arrhythmias and QT interval prolongation),and bradyarrhythmias(bradycardia and heart block).Different mechanisms by which these dysglycemic states might provoke cardiac arrhythmias have been identified in experimental studies.A customized glycemic control strategy to minimize the risk of hyperglycemia,hypoglycemia and glucose variability is of the utmost importance in order to mitigate the risk of cardiac arrhythmias.

Cardiac arrhythmia with premature ventricular contractures induced by interferon beta in a patient with multiple sclerosis

Multiple sclerosis(MS)is an immune‑mediated inflammatory and neurodegenerative disease of the central nervous system.Interferon(IFN)beta is an active ingredient of five out of twelve disease modifying treatments approved for MS.We report a case of IFN‑beta‑induced cardiac arrhythmia with premature ventricular contractures in a patient recently diagnosed with MS.

Repeated atrial arrhythmia induced by cochineal red poisoning:A case report

BACKGROUND Cochineal red is an organic compound widely used in food,cosmetics,pharmaceuticals,textiles,and other fields due to its excellent safety profile.Poisoning caused by eating foods containing cochineal red is rare,and repeated atrial arrhythmia due to cochineal red poisoning is even rarer.CASE SUMMARY An 88-year-old Asian female patient was admitted to hospital due to a disturbance of consciousness.Twelve hours prior to presentation,the patient consumed 12 eggs containing cochineal red over a period of 2 h.At presentation,the patient was in a coma and had a score of 6 on the Glasgow Coma Scale(E2+VT+M4).The patient’s skin and mucous membranes were pink.Electrocardiography(ECG)revealed rapid atrial fibrillation without any signs of ischemia.We prescribed cedilan and fluid replacement for arrhythmia correction.Shortly after admission,the atrial fibrillation corrected to a normal sinus rhythm.On the day 2 of admission,the patient had a sudden atrial flutter accompanied by hemodynamic instability and rapidly declining arterial oxygen saturation between 85%and 90%.The sinus rhythm returned to normal after two electrical cardioversions.Six days after admission,the skin color of the patient returned to normal,and the ECG results were normal.The patient was transferred out of the intensive care unit and eventually discharged after 12 d in hospital.At the 2-mo follow-up visit,the patient was in good health with no recurrence of arrhythmia.CONCLUSION Although cochineal red is a safe,natural food additive,excessive consumption or occupational exposure can induce cardiac arrhythmias.

Control of cardiac excitability and arrhythmias by microRNAs

Recent studies revealing the important roles of microRNAs（miRNAs） in regulating expression of ion channel genes have opened up a research field for extending and deepening our investi- gation into the cardiac excitability and the associated arrhythmogenesis.Cardiac excitability,the fundamental property of the cardiac myocytes,defines the cardiac conduction,repolarization,automaticity,intracellular calcium handling,and their regional heterogeneity. Our previous and ongoing studies and the work from other laboratories have demonstrated the significant involvement of miRNAs in regulating every aspects of cardiac excitability.We have found earlier that the muscle-specific miRNA miR-1 boosts up the arrhythmogenic potential through targeting gap junction channel connexin 43 in myocardial infarction.A subsequent study revealed that miR-1 can also cause arrhythmias by impairing Ca2+ handling by targeting phosphatase.We then identified another muscle-specific miRNA miR-133 promotes abnormal QT prolongation by repressing HERG K+ channel expression in diabetic cardiomyopathy. Subsequently,we discovered that both miR- 1 and miR-133 are involved in the reexpression of pacemaker channels HCN2/HCN4 to enhance abnormal automaticity in cardiac hypertrophy.Recently, we further identified miR-328 as an important determinant for atrial fibrillation（AF） and the associated adverse atrial electrical remodeling via targeting L-type Ca2+ channels.While all the above-mentioned miRNAs are proarrhythmic,we have newly identified for the first time a natural antiarrhythmic miRNA miR-26.We found that all three members of the miR-26 family is downregulated in their expression in AF tissues and this downregulation increases AF vulnerability as a result of removal of an endogenous antiarrhythmic factor.miR-26 downregulation shortens atrial action potential favoring AF by increasing inward rectifier K+ current（IK1） density. This is caused by an upregulation of Kir2.1 K+ channel subunit due to derepression of its encoding gene KCNJ2 as we have validated KCNJ2 as a target gene for miR-26.Administration of a LNA-modified antimiR-26 antisense through tail vein injection increases AF vulnerability as indicated by increased number of mice with AF induction by intracardiac pacing.And this effect is blunted by co-injection of either an adenovirus vector carrying miR-26 precursor sequence or a LNA-modified miR-26 mimic to specifically target KCNJ2.We further discovered that the activity of NFAT transcription factor is enhanced in AF which represses the transcription of miR-26. We characterized the promoter region of the host genes of all three members of the miR-26 miRNA family and identified a common cis-acting element for NFAT binding.Thus,our study unraveled a novel miRNA signaling pathway AF NFAT miR-26 KC-NJ2 /Kir2.1/IK1 AF as a positive feedback loop favoring AF and the remodeling process.

Cardiac autonomic nerve distribution and arrhythmia

OBJECTIVE： To analyze the distribution characteristics of cardiac autonomic nerves and to explore the correlation between cardiac autonomic nerve distribution and arrhythmia. DATA RETRIEVAL： A computer-based retrieval was performed for papers examining the distribution of cardiac autonomic nerves, using “heart, autonomic nerve, sympathetic nerve, vagus nerve, nerve distribution, rhythm and atrial fibrillation” as the key words. SELECTION CRITERIA： A total of 165 studies examining the distribution of cardiac autonomic nerve were screened, and 46 of them were eventually included. MAIN OUTCOME MEASURES： The distribution and characteristics of cardiac autonomic nerves were observed, and immunohistochemical staining was applied to determine the levels of tyrosine hydroxylase and acetylcholine transferase （main markers of cardiac autonomic nerve distribution）. In addition, the correlation between cardiac autonomic nerve distribution and cardiac arrhythmia was investigated. RESULTS： Cardiac autonomic nerves were reported to exhibit a disordered distribution in different sites, mainly at the surface of the cardiac atrium and pulmonary vein, forming a ganglia plexus. The distribution of the pulmonary vein autonomic nerve was prominent at the proximal end rather than the distal end, at the upper left rather than the lower right, at the epicardial membrane rather than the endocardial membrane, at the left atrium rather than the right atrium, and at the posterior wall rather than the anterior wall. The main markers used for cardiac autonomic nerves were tyrosine hydroxylase and acetylcholine transferase. Protein gene product 9.5 was used to label the immunoreactive nerve distribution, and the distribution density of autonomic nerves was determined using a computer-aided morphometric analysis system. CONCLUSION： The uneven distribution of the cardiac autonomic nerves is the leading cause of the occurrence of arrhythmia, and the cardiac autonomic nerves play an important role in the occurrence, maintenance, and symptoms of arrhythmia.

锂中毒导致心律失常、血流动力学障碍1例

双相情感障碍是指临床上既有躁狂或轻躁狂发作,又有抑郁发作的一类心境障碍。锂盐是治疗双相情感障碍的一线药物,但其治疗剂量与中毒剂量较接近,当血锂浓度超过1.4 mmol/L时即可产生中毒症状,通常包括胃肠道反应和中枢神经系统症状等。心脏毒性在锂中毒相关病例中较为少见,但后果极为严重。本研究报道1例双相情感障碍患者,在每日超医嘱剂量服用碳酸锂缓释片,同时联用其他心境稳定剂后,血锂浓度达到6.08 mmol/L,并出现心律失常、休克、意识障碍、粗大震颤等症状,在经过血液透析等对症支持治疗后,患者躯体症状逐渐缓解。临床医生有必要加强对锂中毒的预防和识别。

决奈达隆联合美托洛尔应用于老年房性心律失常患者的疗效观察

目的 探讨决奈达隆联合小剂量美托洛尔治疗快速性房性心律失常的疗效。方法 选取2020年1月至2022年1月江苏省苏北人民医院收治的老年快速性房性心律失常患者160例,按照掷币法随机分为决奈达隆组57例、美托洛尔组55例和联合(决奈达隆+美托洛尔)组48例。比较3组用药前后心律失常发作次数、持续时间及症状变化等发生情况。结果 用药3个月和6个月后,联合组总有效率显著高于决奈达隆组和美托洛尔组,差异有统计学意义(P<0.05)。用药6个月后,联合组心房颤动(AF)发作次数[(2.31±1.78)次/48 h vs(11.56±18.68)次/48 h]、AF持续时间[(4.86±6.73)h/48 h vs(10.92±9.61)h/48 h]、心房扑动(AFL)发作次数[(2.33±1.53)次/48 h vs(4.33±1.53)次/48 h],AFL持续时间[(5.15±4.87)h/48 h vs(21.54±20.08)h/48 h]少于用药前,决奈达隆组AFL持续时间[(2.75±1.94)h/48 h vs(10.29±8.04)h/48 h]明显少于用药前,差异有统计学意义(P<0.05)。结论 决奈达隆联合小剂量美托洛尔治疗快速性房性心律失常不仅能明显改善症状,还能显著减少房性期前收缩、房性心动过速发作次数,减少AF、AFL的发作次数及持续时间,可有效控制心率。

心律不齐患者自适应前瞻性心电触发窄窗冠状动脉CT血管成像扫描的可行性

目的分析心律不齐患者行冠状动脉CT血管成像检查中采用前瞻性心电触发扫描的应用效果。资料与方法前瞻性选择2017年5月—2020年5月首都医科大学宣武医院收诊的心律不齐患者124例,随机分为两组,对照组58例采用回顾性心电门控冠状动脉检查;研究组66例采用前瞻性心电触发扫描,比较两组诊断结果、图像质量评分、对比剂用量和辐射剂量情况。结果两组诊断准确率均在95%以上,差异无统计学意义(P>0.05);研究组患者左前降支、左回旋支、右冠状动脉图像质量与对照组一致,平均主观评分分别为4.16比4.07、3.98比4.22、4.03比4.01,但对比剂用量、有效辐射剂量均明显低于对照组,分别减少29%和39%,差异均有统计学意义(t=32.811、9.119,P=0.001)。结论对于心律不齐患者,前瞻性心电触发扫描窄窗技术保证冠状动脉成像的图像质量,与常规回顾式扫描诊断准确性相当,同时能提高检查安全性,减少辐射剂量。