Caffeine is a widely consumed stimulant known for its cardiovascular and metabolic effects.However,its impact on cardiovascular risk,including arrhythmias,in older adults remains underexplored.Emerging evidence highli...Caffeine is a widely consumed stimulant known for its cardiovascular and metabolic effects.However,its impact on cardiovascular risk,including arrhythmias,in older adults remains underexplored.Emerging evidence highlights sex-specific differences in caffeine metabolism,which may influence its role in cardiovascular health.This perspective examines the interaction between caffeine,hormonal changes,metabolic processes,and lifestyle factors,focusing on older women compared to men.Understanding these differences is essential for tailoring dietary and clinical recommendations to mitigate cardiovascular risks and promote healthy aging.展开更多
Background:A greater prevalence of arrhythmias has been described in endurance athletes,but it remains unclear whether this risk persists after detraining.We aimed to evaluate the prevalence of arrhythmias and their r...Background:A greater prevalence of arrhythmias has been described in endurance athletes,but it remains unclear whether this risk persists after detraining.We aimed to evaluate the prevalence of arrhythmias and their relationship with cardiac remodeling in lifelong and retired master endurance athletes compared to non-athletic controls.Methods:We performed a cross-sectional analysis of observational studies that used echocardiography and cardiac magnetic resonance to detail cardiac structure and function,and Holter monitors to identify atrial and ventricular arrhythmias in 185 endurance athletes and 81 non-athletic controls aged≥40 years.Athletes were categorized as active lifelong(n=144)or retired(n=41)based on hours per week of high-intensity endurance exercise within 5 years of enrollment and validated by percentage of predicted maximal oxygen consumption(VO_(2max)).Athletes with overt cardiomyopathies,channelopathies,pre-excitation,and/or myocardial infarction were excluded.Results:Lifelong athletes(median age=55 years(interquartile range(IQR):46-62),79%male)were significantly fitter than retired athletes(median age=66 years(IQR:58-71),95%male)and controls(median age=53 years(IQR:48-60),96%male),respectively(predicted VO_(2max):131%±18%vs.99%±14%vs.98%±15%,p<0.001).Compared to controls,athletes in our cohort had a higher prevalence of atrial fibrillation((AF):32%vs.0%,p<0.001)and non-sustained ventricular tachycardia((NSVT):9%vs.1%,p=0.007).There was no difference in prevalence of any arrhythmia between lifelong and retired athletes.Lifelong athletes had larger ventricular volumes than retired athletes,who had ventricular volumes similar to controls(left ventricular end-diastolic volume indexed to body surface area(LVEDVi):101±20 m L/m^(2)vs.86±16 mL/m^(2)vs.94±18 mL/m^(2),p<0.001;right ventricular end-diastolic volume indexed to body surface area(RVEDVi):117±23 mL/m^(2)vs.101±19 mL/m^(2)vs.100±19 mL/m^(2),p<0.001).Athletes had more scar(40%vs.18%,p=0.002)and larger left atria(median volume=45m L/m^(2)(IQR:38-52)vs.31 mL/m^(2)(IQR:25-38),p<0.001)than controls,with no difference in atrial volumes and non-ischaemic scar between the athlete groups.Conclusion:Master endurance athletes have a higher prevalence of AF and NSVT than non-athletic controls.Whereas ventricular remodeling tends to reverse with detraining,the propensity to arrhythmias persists regardless of whether they are actively exercising or retired.展开更多
Arrhythmias stand out for having irregular cardiac rhythms,and the fast diagnosis of arrhythmias holds significant clinical importance due to its potential to mitigate adverse health outcomes.Despite the progress in t...Arrhythmias stand out for having irregular cardiac rhythms,and the fast diagnosis of arrhythmias holds significant clinical importance due to its potential to mitigate adverse health outcomes.Despite the progress in this field,existing research efforts have encountered limitations,necessitating innovative approaches to address diagnostic challenges effectively.The primary objective of this research is to propose an innovative classification methodology for distinguishing five distinct arrhythmia classes:atrial premature beat(A),normal(N),ventricular premature beat(V),right bundle branch block(R),and left bundle branch block(L).The proposed methodology involves constructing a hybrid model that incorporates an attention mechanism,utilizing electrocardiogram(ECG)data from an open-source repository.Additionally,we have incorporated an explainability feature into the model,allowing for the interpretation and explanation of its predictions.This model is designed to capitalize on the unique features of arrhythmic patterns and enhance classification metrics.Innovative techniques employed within the methodology are detailed to elucidate the rationale behind their selection and their anticipated contributions to improved model performance.Findings from this study underscore the superiority of the proposed classification model over existing methodologies.Quantitative analysis demonstrates its outstanding performance.The approach,outperforming existing methods,achieves high levels of accuracy(99.16%),specificity(99.79%),recall(99.20%),precision(99.20%),F1-measure(99.16%),and AUC(99.92%).This research advances medical diagnostics by integrating advanced machine-learning techniques to enhance arrhythmia detection.展开更多
Lung transplantation(LT)is now an accepted therapy for end stage lung disease in appropriate patients.Atrial arrhythmias(AA)can occur after LT.Early AA after LT are most often atrial fibrillation,whereas late arrhythm...Lung transplantation(LT)is now an accepted therapy for end stage lung disease in appropriate patients.Atrial arrhythmias(AA)can occur after LT.Early AA after LT are most often atrial fibrillation,whereas late arrhythmias which occur many months or years after LT are often atrial tachycardia.The causes of AA are multifactorial.The review begins with a brief history of LT and AA.This review further describes the pathophysiology of the AA.The risk factors,incidence,recipient characteristics including intra-operative factors are elaborated on.Since there are no clear and specific guidelines on the management of atrial arrhythmia following LT,the recommended guidelines on the management of AA in general are often extrapolated and used in the setting of post LT arrhythmia.The strategy of rate control vs rhythm control is discussed.The pros and cons of various drug regimen,need for direct current cardioversion and catheter ablation therapies are considered.Possible methods to prevent or reduce the incidence of AA after LT are considered.The impact of AA on the short-term and long-term outcomes following LT is discussed.展开更多
Objective: To explore the effect and mechanism of angiotensin II receptor blockers-Irbesartan on occurrence of ventricular arrhythmias in rats with myocardial ischemia. Methods: Rats with embryonic cardiomyocytes-H9c2...Objective: To explore the effect and mechanism of angiotensin II receptor blockers-Irbesartan on occurrence of ventricular arrhythmias in rats with myocardial ischemia. Methods: Rats with embryonic cardiomyocytes-H9c2 were randomly divided into control group. ischemia group. Irbesartan group and Irbesartan+ischemia group. The cell viability of rats in each group was tested using MTT. Real-time PCR was employed to detect the expression of connexin43 (Cx43) mRNA and western blot to detect the expression of Cx43 and phosphorylated Cx43. SD rats were randomly divided into the sham-operation group (SO). myocardial infarction group (MI). Irbesartan group and MI+ Irbesartan group, with 10 rats in each group. HE staining was employed to observe the change in the pathomorpholouy of left ventricular tissue and TUNEL method to analyze the cell apoptosis in the tissue. The immunofluorescence was adopted to observe the expression and distribution of Cx43 in the left ventricular myocardium and study the change in the expression of Cx43 in the cardiac muscular tissue at mRNA and protein level. Results: The intervention of lrbesartan in the condition of ischemia indicated the significant decrease in the number of necrotic cells. The expression of Cx43 was significantly decreased under the culture of ischemia (P<0.05), but in the presence of Irbesartan, the expression of Cx43 was increased compared with the ischemia group (p<0.01). The results of WB assay showed the similar trend of change at mRNA level. There was the significant difference in the score of ventricular arerythmia between MI group and SO group (P<0.01). The incidence of ventricular tachycardia or ventricular fibrillation was significantly increased compared with the one in SO group (P<0.05). There was the significant difference in the overall score between MI+Irbesartan group and MI group (P<0.05). The expression of Cx43 in the cardiac muscular tissue in MI group was significantly decreased (P<0.01(US) SO group). But the expression of Cx43 was increased after the treatment with Irbesartan. Conclusions: Irbesartan can inhibit the injury of H9c2 cardiomyocytes and the decreased expression of Cx43 that are induced by the ischemic myocardial infarction. Irbesartan can also improve the reconstruction of Cx43 in rats with ischemic myocardium to inhibit the myocardial infarction-induced arrhythmias.展开更多
This work is aimed at exploring the clinical efficacy of continuous positive airway pressuie(CPAP)in treatment of patients with arrhythmias combined with obstructive sleep apnea(OSA).Through evaluating serum native th...This work is aimed at exploring the clinical efficacy of continuous positive airway pressuie(CPAP)in treatment of patients with arrhythmias combined with obstructive sleep apnea(OSA).Through evaluating serum native thiol,malonaldehyde(MDA)and nicotinamide adenine dinucleotide phosphate oxidase(NADPH oxidase)in these patients and describing the effects on oxidative parameters of CPAP therapy for 3 months,we confirmed the impact of oxidative stress on arrhythmias.A total of 64 patients with OSA combined with arrhythmias were collected from April 2014 to April 2017 with full clinical information.Patients were divided into two groups(paired experiment design):32 patients in group A(control group),who received unchanged anti-arrhythmia treatment and 32 patients in group B,who were subjected to unchanged pharmacological anti-arrhythmia therapy combined with CPAP.OSA related parameters were compared between the two groups after 3-month therapy.And the levels of parameters of oxidative stress in patients were measured before and after CPAP therapy.After 3 months of CPAP therapy,compared with the control group,the percentage of sage N3(NREM 3)and stage R(REM)in total sleep time was significantly increased,while apnea-hypopnea index(AHI)and the Epworth Sleepiness Scale(ESS)score were evidently decreased.Meanwhile,the lowest oxygen saturation(LSpCh)was also elevated after CPAP treatment for 3 months.The CPAP therapy significantly prevented the occurrence of arrhythmias(P<0.05).Both the MDA level and NADPH oxidase levels were significantly lower in the group B than in the group A(P<0.05).But serum native thiol was improved by CPAP treatment(P<0.05).In conclusion,proper use of CPAP therapy provides significant benefits for the treatment of arrhythmia in patients with OSA.展开更多
Objective To investigate whether C-reactive protein (CRP) is a biomarker of malignant ventricular arrhythmias (MVA) occurring in non-ST elevation myocardial infarction (NSTEMI) patients with Global Registry of Acute C...Objective To investigate whether C-reactive protein (CRP) is a biomarker of malignant ventricular arrhythmias (MVA) occurring in non-ST elevation myocardial infarction (NSTEMI) patients with Global Registry of Acute Coronary events (GRACE) scores < 140. Methods A total of 1450 NSTEMI patients were included in this study. Hs-CRP blood levels were measured via a turbidimetric immunoassay after confirming the diagnosis of NSTEMI with GRACE scores < 140. Results Consistent with prior studies, the MVA occurrence rate in our cohort was 6.7%, and patients with MVA exhibited a reduced left ventricular ejection fraction (46.1%± 6.9% vs. 61.5%± 8.7%, P = 0.032), a higher incidence of Killip classification > 1 (34.1% vs. 24.2%, P < 0.001), an increased surgical revascularization rate (34.1% vs. 9.7%, P < 0.001), and increased mortality (16.5% vs. 5.8%, P < 0.001). Serum hs-CRP levels were higher (P = 0.003) in NSTEMI patients with MVA, and this increase appeared unrelated to other clinical parameters. The C-statistic to discriminate MVA was 0.82 (95% CI: 0.74–0.89). Using receiver operating characteristics analysis, we optimized a cutoff point of 16 mL/L, and the sensitivity and specificity were 95% and 61%, respectively;the positive predictive value was 20% and the negative predictive value was 99%. Conclusions An hs-CRP assay is a potential MVA biomarker in low-risk NSTEMI patients with GRACE scores < 140. If validated in prospective studies, hs-CRP may offer a low-cost supplementary strategy for risk stratification for NSTEMI patients.展开更多
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 detecti...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.展开更多
Objective To evaluate the PR to RR interval ratio (PR/RR,heart rate-adjusted PR) as a prognostic marker for long-term ventricular arrhythmias and cardiac death in patients with implantable cardioverter defibrillator (...Objective To evaluate the PR to RR interval ratio (PR/RR,heart rate-adjusted PR) as a prognostic marker for long-term ventricular arrhythmias and cardiac death in patients with implantable cardioverter defibrillator (ICDs) and cardiac resynchronization therapy with defibrillators (CRT-D).Methods We retrospectively analyzed data from 428 patients who had an ICD/CRT-D equipped with home monitoring.Baseline PR and RR interval data prior to ICD/CRT-D implantation were collected from standard 12-lead electrocardiograph,and the PR/RR was calculated.The primary endpoint was appropriate ICD/CRT-D treatment of ventricular arrhythmias (VAs),and the secondary endpoint was cardiac death.Results During a mean follow-up period of 38.8 ± 10.6 months,197 patients (46%) experienced VAs,and 47 patients (11%) experienced cardiac death.The overall PR interval was 160 ± 40 ms,and the RR interval was 866 ± 124 ms.Based on the receiver operating characteristic curve,a cut-off value of 18.5% for the PR/RR was identified to predict VAs.A PR/RR ≥ 18.5% was associated with an increased risk of VAs [hazard ratio (HR)= 2.243,95% confidence interval (CI)= 1.665–3.022,P < 0.001) and cardiac death (HR = 2.358,95%CI = 1.240–4.483,P = 0.009) in an unadjusted analysis.After adjustment in a multivariate Cox model,the relationship remained significant among PR/RR ≥ 18.5%,VAs (HR = 2.230,95%CI = 1.555–2.825,P < 0.001) and cardiac death (HR = 2.105,95%CI = 1.101–4.025,P = 0.024.Conclusions A PR/RR ≥ 18.5% at baseline can serve as a predictor of future VAs and cardiac death in ICD/CRT-D recipients.展开更多
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 c...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.展开更多
In March 2020,the WHO defined the diffusion of novel coronavirus,Severe Acute Respiratory Syndrome-Coronavirus-2(SARS-CoV-2)as pandemic.[1-3]As a consequence,the Italian Government among others has enforced quarantine...In March 2020,the WHO defined the diffusion of novel coronavirus,Severe Acute Respiratory Syndrome-Coronavirus-2(SARS-CoV-2)as pandemic.[1-3]As a consequence,the Italian Government among others has enforced quarantine on the population to contain the diffusion of the infection.Quarantine refers to the separation of communities who have been exposed to an infectious disease.[1-3]Elderly people's lives have been drastically affected by the lockdown and the fear related to the disease’s potential effects and transmission.Fear of contracting COVID-19 is on the rise due to the death toll and alarming news reports in the media.[2,3].展开更多
Fetal arrhythmias reach up around 10%of the total third-level perinatal cardiology references.Sustained bradycardia is defined as a baseline fetal heart rate(FHR)of less than 110 bpm sustained for at least 10 min.The ...Fetal arrhythmias reach up around 10%of the total third-level perinatal cardiology references.Sustained bradycardia is defined as a baseline fetal heart rate(FHR)of less than 110 bpm sustained for at least 10 min.The overall incidence of malignant fetal bradyarrhythmias,such as complete atrioventricular block(AVB)and channellopathies,is relatively rare,1:5000 pregnancies,but represents a serious emergency for the gynecologist,neonatologists,and pediatric cardiologists.Fetal complete AVB is strongly associated with maternal connective tissue disease,but it can be also associated with congenital heart disease and usually with a poorer prognosis with high risk of fetal hydrops and abortion.Currently,the treatment of severe fetal bradyarrhythmias is principally pharmacological and aims to increase the FHR,besides an early resolution of underlying causes,when possible,and a promptly management of fetal heart failure.Intrauterine electrostimulation nowadays is an experimental pioneering method,reserved for limited selected cases.展开更多
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 car...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.展开更多
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 a...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.展开更多
A canine model of ischemic ventricular tachyarrhythmias was established in open-chest dogs subjected to programmed electrical stimulation (PES) for 5￣8 days after acute myocardial infarction. The electrophysiologic e...A canine model of ischemic ventricular tachyarrhythmias was established in open-chest dogs subjected to programmed electrical stimulation (PES) for 5￣8 days after acute myocardial infarction. The electrophysiologic effects of sophoridine (Sop) and procainamide (PA) were observed in this canine model. With routine methods of PES, ventricular tachycardia (VT) and ventricular fibrilation (VF) could be reproducibly initiated in this model. Both drugs distinctly lengthened the QTc interval ( P <0.01) and the effective refractory period (ERP) in normal and ischemic ventricular myocardium ( P <0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P <0.05), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably ( P <0.01). Both drugs effectively prevented the PES-induced VT or VF and ischemia-induced VF ( P <0.05). The results indicated that this canine model is a good and reliable one, sophoridine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage.展开更多
Prophylactic effect of magnesium sulfate on reperfusion arrhythmias was studiedusing a left anterior descending coronary artery occlusion followed by reperfusion in theisolated rat heart.In the first studies,we have o...Prophylactic effect of magnesium sulfate on reperfusion arrhythmias was studiedusing a left anterior descending coronary artery occlusion followed by reperfusion in theisolated rat heart.In the first studies,we have observed a bell-shaped relationship be-tween the incidence of reperfusion-induced ventricular fibrillation（VF）and the durationof preceding ischemia.With 5,10,15,20 and 25 min of ischemia,10,70,60,50 and 20per cent of the hearts exhibited irreversible VF,respectively.In the second studies（10 minischemia）,perfusate magnesium sulfate was increased to 3.6,4.8 and 6.0 mmol/L 1 min be-fore coronary ligation,VF fell in a dose-dependent manner from its control total inci-dence of 100%（1.2mmol/L MgSO<sub>4</sub>）to 82%,73% and 18%（P【0.01）,respectively.Heartrate was also reduced in a dose-dependent manner,falling from its control value of326±11 to 227±22 beats/min with the highest concentration of magnesium sulfate.Asperfusate magnesium sulfate was increased to 6.0 mmol/L just before reperfusion,no an-ti-arrhythmic effects were observed.With an anti-arrhythmic concentration of magnesiumsulfate（6.0 mmol/L,increased 1 min before ligation）,calcium concentration was increasedby 1.5 mmol/L at the same time,under these conditions the anti-arrhythmic effect of mag-nesium sulfate was lost and its negative chronotropic effect was also partially abolished.We conclude that magnesium sulfate has a certain prophylactic effect againstreperfusion induced arrhythmias and this could be due to a direct or indirect calci-um-antagonist action.展开更多
Sudden cardiac death related to athletic competition is a rare but tragic event.The victims are typically young with no previous cardiovascular symptoms or limitations.The majority of sudden cardiac death events in at...Sudden cardiac death related to athletic competition is a rare but tragic event.The victims are typically young with no previous cardiovascular symptoms or limitations.The majority of sudden cardiac death events in athletes are due to ventricular arrhythmias as a result of underlying molecular and/or structural level pathologic substrate.In this article,we will review the physiologic cardiac adaptations to exercise along with arrhythmias seen in athletes with a focus on those commonly associated with sudden cardiac death.展开更多
Effect of berberine on reperfusion arrhythmias was studied using a10min left anterior descending coronary artery occlusion followed by reperfusionin the isolated rat heart.Berberine when given 10min before coronary li...Effect of berberine on reperfusion arrhythmias was studied using a10min left anterior descending coronary artery occlusion followed by reperfusionin the isolated rat heart.Berberine when given 10min before coronary ligation re-duced the incidence of reperfusion arrhythmias in a dose-dependent manner.With10<sup>-5</sup>,3.16×10<sup>-5</sup> and 10<sup>-4</sup>mol/L of berberine,ventricular fibrillation was reducedfrom its control incidence of 100% to 90%,70% and 40% （P【0.05） respectively.Heart rate was also reduced in a dose-dependent manner,falling from its controlvalue of 282±11 to 180±11 beats/min with the highest concentration of berberine.Coronary flow was increased in all berberine treated groups.With anantiarrhythmic dose of berberine (10<sup>-4</sup>mol/L),hearts were paced （5 Hz） duringischemia period;under these conditions the anti-arrhythmic effect of berberinewas lost.When berberine (3.16×10<sup>-5</sup> and 10<sup>-4</sup>mol/L) was administered just beforereperfusion,no anti-arrhythmic effects were observed.The α-adrenoceptor antago-nist phentolamine (2.6×10<sup>-5</sup>mol/L) prevented reperfusion arrhythmias and ismuch more effective than berberine.These results suggest that the prophylatic ef-fects of berberine on reperfusion arrhythmias in the isolated rat heart are due toits negative chronotropic properties.展开更多
In healthcare,the persistent challenge of arrhythmias,a leading cause of global mortality,has sparked extensive research into the automation of detection using machine learning(ML)algorithms.However,traditional ML and...In healthcare,the persistent challenge of arrhythmias,a leading cause of global mortality,has sparked extensive research into the automation of detection using machine learning(ML)algorithms.However,traditional ML and AutoML approaches have revealed their limitations,notably regarding feature generalization and automation efficiency.This glaring research gap has motivated the development of AutoRhythmAI,an innovative solution that integrates both machine and deep learning to revolutionize the diagnosis of arrhythmias.Our approach encompasses two distinct pipelines tailored for binary-class and multi-class arrhythmia detection,effectively bridging the gap between data preprocessing and model selection.To validate our system,we have rigorously tested AutoRhythmAI using a multimodal dataset,surpassing the accuracy achieved using a single dataset and underscoring the robustness of our methodology.In the first pipeline,we employ signal filtering and ML algorithms for preprocessing,followed by data balancing and split for training.The second pipeline is dedicated to feature extraction and classification,utilizing deep learning models.Notably,we introduce the‘RRI-convoluted trans-former model’as a novel addition for binary-class arrhythmias.An ensemble-based approach then amalgamates all models,considering their respective weights,resulting in an optimal model pipeline.In our study,the VGGRes Model achieved impressive results in multi-class arrhythmia detection,with an accuracy of 97.39%and firm performance in precision(82.13%),recall(31.91%),and F1-score(82.61%).In the binary-class task,the proposed model achieved an outstanding accuracy of 96.60%.These results highlight the effectiveness of our approach in improving arrhythmia detection,with notably high accuracy and well-balanced performance metrics.展开更多
Crdiovascular diseases (CVD) incur a heavy burden of morbidity and mortality among patients with chronic kidney disease (CKD),particularly among the elderly.It is estimated that about 22-25% of all adults beyond the a...Crdiovascular diseases (CVD) incur a heavy burden of morbidity and mortality among patients with chronic kidney disease (CKD),particularly among the elderly.It is estimated that about 22-25% of all adults beyond the age of 65 years have moderate or severe renal dysfunction.1。展开更多
文摘Caffeine is a widely consumed stimulant known for its cardiovascular and metabolic effects.However,its impact on cardiovascular risk,including arrhythmias,in older adults remains underexplored.Emerging evidence highlights sex-specific differences in caffeine metabolism,which may influence its role in cardiovascular health.This perspective examines the interaction between caffeine,hormonal changes,metabolic processes,and lifestyle factors,focusing on older women compared to men.Understanding these differences is essential for tailoring dietary and clinical recommendations to mitigate cardiovascular risks and promote healthy aging.
基金funded by the National Health and Medical Research Council of Australia(Grant No.APP1130353)supported by a Royal Australian College of Physicians Research Entry Scholarship(Grant No.2023RES00039)+4 种基金The National Health and Medical Research Council Postgraduate Scholarship(Grant No.2031119)a Heart Foundation PhD Scholarship(Grant No.107659)supported through an Australian Government Research Training Program Scholarshipsupported as a postdoctoral clinical researcher by the Fund for Scientific Research Flanderssupported by a National Health and Medical Research Council of Australia Investigator Grant(Grant No.APP 2027105)。
文摘Background:A greater prevalence of arrhythmias has been described in endurance athletes,but it remains unclear whether this risk persists after detraining.We aimed to evaluate the prevalence of arrhythmias and their relationship with cardiac remodeling in lifelong and retired master endurance athletes compared to non-athletic controls.Methods:We performed a cross-sectional analysis of observational studies that used echocardiography and cardiac magnetic resonance to detail cardiac structure and function,and Holter monitors to identify atrial and ventricular arrhythmias in 185 endurance athletes and 81 non-athletic controls aged≥40 years.Athletes were categorized as active lifelong(n=144)or retired(n=41)based on hours per week of high-intensity endurance exercise within 5 years of enrollment and validated by percentage of predicted maximal oxygen consumption(VO_(2max)).Athletes with overt cardiomyopathies,channelopathies,pre-excitation,and/or myocardial infarction were excluded.Results:Lifelong athletes(median age=55 years(interquartile range(IQR):46-62),79%male)were significantly fitter than retired athletes(median age=66 years(IQR:58-71),95%male)and controls(median age=53 years(IQR:48-60),96%male),respectively(predicted VO_(2max):131%±18%vs.99%±14%vs.98%±15%,p<0.001).Compared to controls,athletes in our cohort had a higher prevalence of atrial fibrillation((AF):32%vs.0%,p<0.001)and non-sustained ventricular tachycardia((NSVT):9%vs.1%,p=0.007).There was no difference in prevalence of any arrhythmia between lifelong and retired athletes.Lifelong athletes had larger ventricular volumes than retired athletes,who had ventricular volumes similar to controls(left ventricular end-diastolic volume indexed to body surface area(LVEDVi):101±20 m L/m^(2)vs.86±16 mL/m^(2)vs.94±18 mL/m^(2),p<0.001;right ventricular end-diastolic volume indexed to body surface area(RVEDVi):117±23 mL/m^(2)vs.101±19 mL/m^(2)vs.100±19 mL/m^(2),p<0.001).Athletes had more scar(40%vs.18%,p=0.002)and larger left atria(median volume=45m L/m^(2)(IQR:38-52)vs.31 mL/m^(2)(IQR:25-38),p<0.001)than controls,with no difference in atrial volumes and non-ischaemic scar between the athlete groups.Conclusion:Master endurance athletes have a higher prevalence of AF and NSVT than non-athletic controls.Whereas ventricular remodeling tends to reverse with detraining,the propensity to arrhythmias persists regardless of whether they are actively exercising or retired.
基金supported by the National Natural Science Foundation of China under Grant No.62271127the Medico-Engineering Cooperation Funds from University of Electronic Science and Technology of China and the West China Hospital of Sichuan University under Grants No.ZYGX2022YGRH011 and No.HXDZ22005+1 种基金the Natural Science Foundation of Sichuan,China under Grant No.23NSFSC0627Sichuan Provincial Key Laboratory Fund for Ultra Sound Cardioelectrophysiology and Biomechanics,China under Grant No.2023KFKT01.
文摘Arrhythmias stand out for having irregular cardiac rhythms,and the fast diagnosis of arrhythmias holds significant clinical importance due to its potential to mitigate adverse health outcomes.Despite the progress in this field,existing research efforts have encountered limitations,necessitating innovative approaches to address diagnostic challenges effectively.The primary objective of this research is to propose an innovative classification methodology for distinguishing five distinct arrhythmia classes:atrial premature beat(A),normal(N),ventricular premature beat(V),right bundle branch block(R),and left bundle branch block(L).The proposed methodology involves constructing a hybrid model that incorporates an attention mechanism,utilizing electrocardiogram(ECG)data from an open-source repository.Additionally,we have incorporated an explainability feature into the model,allowing for the interpretation and explanation of its predictions.This model is designed to capitalize on the unique features of arrhythmic patterns and enhance classification metrics.Innovative techniques employed within the methodology are detailed to elucidate the rationale behind their selection and their anticipated contributions to improved model performance.Findings from this study underscore the superiority of the proposed classification model over existing methodologies.Quantitative analysis demonstrates its outstanding performance.The approach,outperforming existing methods,achieves high levels of accuracy(99.16%),specificity(99.79%),recall(99.20%),precision(99.20%),F1-measure(99.16%),and AUC(99.92%).This research advances medical diagnostics by integrating advanced machine-learning techniques to enhance arrhythmia detection.
文摘Lung transplantation(LT)is now an accepted therapy for end stage lung disease in appropriate patients.Atrial arrhythmias(AA)can occur after LT.Early AA after LT are most often atrial fibrillation,whereas late arrhythmias which occur many months or years after LT are often atrial tachycardia.The causes of AA are multifactorial.The review begins with a brief history of LT and AA.This review further describes the pathophysiology of the AA.The risk factors,incidence,recipient characteristics including intra-operative factors are elaborated on.Since there are no clear and specific guidelines on the management of atrial arrhythmia following LT,the recommended guidelines on the management of AA in general are often extrapolated and used in the setting of post LT arrhythmia.The strategy of rate control vs rhythm control is discussed.The pros and cons of various drug regimen,need for direct current cardioversion and catheter ablation therapies are considered.Possible methods to prevent or reduce the incidence of AA after LT are considered.The impact of AA on the short-term and long-term outcomes following LT is discussed.
基金supported by Research Topic of Department of Health of Jiangxi Province(No.20131074)Natural Science Fund of Jiangxi Province(No:20122BAB205028)
文摘Objective: To explore the effect and mechanism of angiotensin II receptor blockers-Irbesartan on occurrence of ventricular arrhythmias in rats with myocardial ischemia. Methods: Rats with embryonic cardiomyocytes-H9c2 were randomly divided into control group. ischemia group. Irbesartan group and Irbesartan+ischemia group. The cell viability of rats in each group was tested using MTT. Real-time PCR was employed to detect the expression of connexin43 (Cx43) mRNA and western blot to detect the expression of Cx43 and phosphorylated Cx43. SD rats were randomly divided into the sham-operation group (SO). myocardial infarction group (MI). Irbesartan group and MI+ Irbesartan group, with 10 rats in each group. HE staining was employed to observe the change in the pathomorpholouy of left ventricular tissue and TUNEL method to analyze the cell apoptosis in the tissue. The immunofluorescence was adopted to observe the expression and distribution of Cx43 in the left ventricular myocardium and study the change in the expression of Cx43 in the cardiac muscular tissue at mRNA and protein level. Results: The intervention of lrbesartan in the condition of ischemia indicated the significant decrease in the number of necrotic cells. The expression of Cx43 was significantly decreased under the culture of ischemia (P<0.05), but in the presence of Irbesartan, the expression of Cx43 was increased compared with the ischemia group (p<0.01). The results of WB assay showed the similar trend of change at mRNA level. There was the significant difference in the score of ventricular arerythmia between MI group and SO group (P<0.01). The incidence of ventricular tachycardia or ventricular fibrillation was significantly increased compared with the one in SO group (P<0.05). There was the significant difference in the overall score between MI+Irbesartan group and MI group (P<0.05). The expression of Cx43 in the cardiac muscular tissue in MI group was significantly decreased (P<0.01(US) SO group). But the expression of Cx43 was increased after the treatment with Irbesartan. Conclusions: Irbesartan can inhibit the injury of H9c2 cardiomyocytes and the decreased expression of Cx43 that are induced by the ischemic myocardial infarction. Irbesartan can also improve the reconstruction of Cx43 in rats with ischemic myocardium to inhibit the myocardial infarction-induced arrhythmias.
文摘This work is aimed at exploring the clinical efficacy of continuous positive airway pressuie(CPAP)in treatment of patients with arrhythmias combined with obstructive sleep apnea(OSA).Through evaluating serum native thiol,malonaldehyde(MDA)and nicotinamide adenine dinucleotide phosphate oxidase(NADPH oxidase)in these patients and describing the effects on oxidative parameters of CPAP therapy for 3 months,we confirmed the impact of oxidative stress on arrhythmias.A total of 64 patients with OSA combined with arrhythmias were collected from April 2014 to April 2017 with full clinical information.Patients were divided into two groups(paired experiment design):32 patients in group A(control group),who received unchanged anti-arrhythmia treatment and 32 patients in group B,who were subjected to unchanged pharmacological anti-arrhythmia therapy combined with CPAP.OSA related parameters were compared between the two groups after 3-month therapy.And the levels of parameters of oxidative stress in patients were measured before and after CPAP therapy.After 3 months of CPAP therapy,compared with the control group,the percentage of sage N3(NREM 3)and stage R(REM)in total sleep time was significantly increased,while apnea-hypopnea index(AHI)and the Epworth Sleepiness Scale(ESS)score were evidently decreased.Meanwhile,the lowest oxygen saturation(LSpCh)was also elevated after CPAP treatment for 3 months.The CPAP therapy significantly prevented the occurrence of arrhythmias(P<0.05).Both the MDA level and NADPH oxidase levels were significantly lower in the group B than in the group A(P<0.05).But serum native thiol was improved by CPAP treatment(P<0.05).In conclusion,proper use of CPAP therapy provides significant benefits for the treatment of arrhythmia in patients with OSA.
基金supported by the Capital Health Research and Development of Special Foundation (2018-1-2061)
文摘Objective To investigate whether C-reactive protein (CRP) is a biomarker of malignant ventricular arrhythmias (MVA) occurring in non-ST elevation myocardial infarction (NSTEMI) patients with Global Registry of Acute Coronary events (GRACE) scores < 140. Methods A total of 1450 NSTEMI patients were included in this study. Hs-CRP blood levels were measured via a turbidimetric immunoassay after confirming the diagnosis of NSTEMI with GRACE scores < 140. Results Consistent with prior studies, the MVA occurrence rate in our cohort was 6.7%, and patients with MVA exhibited a reduced left ventricular ejection fraction (46.1%± 6.9% vs. 61.5%± 8.7%, P = 0.032), a higher incidence of Killip classification > 1 (34.1% vs. 24.2%, P < 0.001), an increased surgical revascularization rate (34.1% vs. 9.7%, P < 0.001), and increased mortality (16.5% vs. 5.8%, P < 0.001). Serum hs-CRP levels were higher (P = 0.003) in NSTEMI patients with MVA, and this increase appeared unrelated to other clinical parameters. The C-statistic to discriminate MVA was 0.82 (95% CI: 0.74–0.89). Using receiver operating characteristics analysis, we optimized a cutoff point of 16 mL/L, and the sensitivity and specificity were 95% and 61%, respectively;the positive predictive value was 20% and the negative predictive value was 99%. Conclusions An hs-CRP assay is a potential MVA biomarker in low-risk NSTEMI patients with GRACE scores < 140. If validated in prospective studies, hs-CRP may offer a low-cost supplementary strategy for risk stratification for NSTEMI patients.
文摘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.
文摘Objective To evaluate the PR to RR interval ratio (PR/RR,heart rate-adjusted PR) as a prognostic marker for long-term ventricular arrhythmias and cardiac death in patients with implantable cardioverter defibrillator (ICDs) and cardiac resynchronization therapy with defibrillators (CRT-D).Methods We retrospectively analyzed data from 428 patients who had an ICD/CRT-D equipped with home monitoring.Baseline PR and RR interval data prior to ICD/CRT-D implantation were collected from standard 12-lead electrocardiograph,and the PR/RR was calculated.The primary endpoint was appropriate ICD/CRT-D treatment of ventricular arrhythmias (VAs),and the secondary endpoint was cardiac death.Results During a mean follow-up period of 38.8 ± 10.6 months,197 patients (46%) experienced VAs,and 47 patients (11%) experienced cardiac death.The overall PR interval was 160 ± 40 ms,and the RR interval was 866 ± 124 ms.Based on the receiver operating characteristic curve,a cut-off value of 18.5% for the PR/RR was identified to predict VAs.A PR/RR ≥ 18.5% was associated with an increased risk of VAs [hazard ratio (HR)= 2.243,95% confidence interval (CI)= 1.665–3.022,P < 0.001) and cardiac death (HR = 2.358,95%CI = 1.240–4.483,P = 0.009) in an unadjusted analysis.After adjustment in a multivariate Cox model,the relationship remained significant among PR/RR ≥ 18.5%,VAs (HR = 2.230,95%CI = 1.555–2.825,P < 0.001) and cardiac death (HR = 2.105,95%CI = 1.101–4.025,P = 0.024.Conclusions A PR/RR ≥ 18.5% at baseline can serve as a predictor of future VAs and cardiac death in ICD/CRT-D recipients.
文摘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.
文摘In March 2020,the WHO defined the diffusion of novel coronavirus,Severe Acute Respiratory Syndrome-Coronavirus-2(SARS-CoV-2)as pandemic.[1-3]As a consequence,the Italian Government among others has enforced quarantine on the population to contain the diffusion of the infection.Quarantine refers to the separation of communities who have been exposed to an infectious disease.[1-3]Elderly people's lives have been drastically affected by the lockdown and the fear related to the disease’s potential effects and transmission.Fear of contracting COVID-19 is on the rise due to the death toll and alarming news reports in the media.[2,3].
文摘Fetal arrhythmias reach up around 10%of the total third-level perinatal cardiology references.Sustained bradycardia is defined as a baseline fetal heart rate(FHR)of less than 110 bpm sustained for at least 10 min.The overall incidence of malignant fetal bradyarrhythmias,such as complete atrioventricular block(AVB)and channellopathies,is relatively rare,1:5000 pregnancies,but represents a serious emergency for the gynecologist,neonatologists,and pediatric cardiologists.Fetal complete AVB is strongly associated with maternal connective tissue disease,but it can be also associated with congenital heart disease and usually with a poorer prognosis with high risk of fetal hydrops and abortion.Currently,the treatment of severe fetal bradyarrhythmias is principally pharmacological and aims to increase the FHR,besides an early resolution of underlying causes,when possible,and a promptly management of fetal heart failure.Intrauterine electrostimulation nowadays is an experimental pioneering method,reserved for limited selected cases.
基金This work was supported by China Postdoctoral Science Foundation(2021M690249)Michigan Medicine-PKUHSC Joint Institute for Translational and Clinical Research(BMU20140467).
文摘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.
文摘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.
文摘A canine model of ischemic ventricular tachyarrhythmias was established in open-chest dogs subjected to programmed electrical stimulation (PES) for 5￣8 days after acute myocardial infarction. The electrophysiologic effects of sophoridine (Sop) and procainamide (PA) were observed in this canine model. With routine methods of PES, ventricular tachycardia (VT) and ventricular fibrilation (VF) could be reproducibly initiated in this model. Both drugs distinctly lengthened the QTc interval ( P <0.01) and the effective refractory period (ERP) in normal and ischemic ventricular myocardium ( P <0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P <0.05), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably ( P <0.01). Both drugs effectively prevented the PES-induced VT or VF and ischemia-induced VF ( P <0.05). The results indicated that this canine model is a good and reliable one, sophoridine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage.
文摘Prophylactic effect of magnesium sulfate on reperfusion arrhythmias was studiedusing a left anterior descending coronary artery occlusion followed by reperfusion in theisolated rat heart.In the first studies,we have observed a bell-shaped relationship be-tween the incidence of reperfusion-induced ventricular fibrillation（VF）and the durationof preceding ischemia.With 5,10,15,20 and 25 min of ischemia,10,70,60,50 and 20per cent of the hearts exhibited irreversible VF,respectively.In the second studies（10 minischemia）,perfusate magnesium sulfate was increased to 3.6,4.8 and 6.0 mmol/L 1 min be-fore coronary ligation,VF fell in a dose-dependent manner from its control total inci-dence of 100%（1.2mmol/L MgSO<sub>4</sub>）to 82%,73% and 18%（P【0.01）,respectively.Heartrate was also reduced in a dose-dependent manner,falling from its control value of326±11 to 227±22 beats/min with the highest concentration of magnesium sulfate.Asperfusate magnesium sulfate was increased to 6.0 mmol/L just before reperfusion,no an-ti-arrhythmic effects were observed.With an anti-arrhythmic concentration of magnesiumsulfate（6.0 mmol/L,increased 1 min before ligation）,calcium concentration was increasedby 1.5 mmol/L at the same time,under these conditions the anti-arrhythmic effect of mag-nesium sulfate was lost and its negative chronotropic effect was also partially abolished.We conclude that magnesium sulfate has a certain prophylactic effect againstreperfusion induced arrhythmias and this could be due to a direct or indirect calci-um-antagonist action.
文摘Sudden cardiac death related to athletic competition is a rare but tragic event.The victims are typically young with no previous cardiovascular symptoms or limitations.The majority of sudden cardiac death events in athletes are due to ventricular arrhythmias as a result of underlying molecular and/or structural level pathologic substrate.In this article,we will review the physiologic cardiac adaptations to exercise along with arrhythmias seen in athletes with a focus on those commonly associated with sudden cardiac death.
文摘Effect of berberine on reperfusion arrhythmias was studied using a10min left anterior descending coronary artery occlusion followed by reperfusionin the isolated rat heart.Berberine when given 10min before coronary ligation re-duced the incidence of reperfusion arrhythmias in a dose-dependent manner.With10<sup>-5</sup>,3.16×10<sup>-5</sup> and 10<sup>-4</sup>mol/L of berberine,ventricular fibrillation was reducedfrom its control incidence of 100% to 90%,70% and 40% （P【0.05） respectively.Heart rate was also reduced in a dose-dependent manner,falling from its controlvalue of 282±11 to 180±11 beats/min with the highest concentration of berberine.Coronary flow was increased in all berberine treated groups.With anantiarrhythmic dose of berberine (10<sup>-4</sup>mol/L),hearts were paced （5 Hz） duringischemia period;under these conditions the anti-arrhythmic effect of berberinewas lost.When berberine (3.16×10<sup>-5</sup> and 10<sup>-4</sup>mol/L) was administered just beforereperfusion,no anti-arrhythmic effects were observed.The α-adrenoceptor antago-nist phentolamine (2.6×10<sup>-5</sup>mol/L) prevented reperfusion arrhythmias and ismuch more effective than berberine.These results suggest that the prophylatic ef-fects of berberine on reperfusion arrhythmias in the isolated rat heart are due toits negative chronotropic properties.
文摘In healthcare,the persistent challenge of arrhythmias,a leading cause of global mortality,has sparked extensive research into the automation of detection using machine learning(ML)algorithms.However,traditional ML and AutoML approaches have revealed their limitations,notably regarding feature generalization and automation efficiency.This glaring research gap has motivated the development of AutoRhythmAI,an innovative solution that integrates both machine and deep learning to revolutionize the diagnosis of arrhythmias.Our approach encompasses two distinct pipelines tailored for binary-class and multi-class arrhythmia detection,effectively bridging the gap between data preprocessing and model selection.To validate our system,we have rigorously tested AutoRhythmAI using a multimodal dataset,surpassing the accuracy achieved using a single dataset and underscoring the robustness of our methodology.In the first pipeline,we employ signal filtering and ML algorithms for preprocessing,followed by data balancing and split for training.The second pipeline is dedicated to feature extraction and classification,utilizing deep learning models.Notably,we introduce the‘RRI-convoluted trans-former model’as a novel addition for binary-class arrhythmias.An ensemble-based approach then amalgamates all models,considering their respective weights,resulting in an optimal model pipeline.In our study,the VGGRes Model achieved impressive results in multi-class arrhythmia detection,with an accuracy of 97.39%and firm performance in precision(82.13%),recall(31.91%),and F1-score(82.61%).In the binary-class task,the proposed model achieved an outstanding accuracy of 96.60%.These results highlight the effectiveness of our approach in improving arrhythmia detection,with notably high accuracy and well-balanced performance metrics.
文摘Crdiovascular diseases (CVD) incur a heavy burden of morbidity and mortality among patients with chronic kidney disease (CKD),particularly among the elderly.It is estimated that about 22-25% of all adults beyond the age of 65 years have moderate or severe renal dysfunction.1。
