Circulating circRNA expression profile and its potential role in late recurrence of paroxysmal atrial fibrillation post catheter ablation

BACKGROUND Catheter-based pulmonary vein isolation(PVI) is an effective and well-established intervention for symptomatic paroxysmal atrial fibrillation(PAF). Nevertheless, late recurrences of atrial fibrillation(LRAF) occurring during 3 to 12months are common, and the underlying mechanisms remain elusive. Circular RNAs(circ RNAs) in atrial tissue have been linked to the pathophysiological mechanisms and progression of PAF in a few studies. However, their expression patterns in peripheral blood and regulatory function in LRAF are not clear.METHODS In the present study, the expression profile of circulating circ RNAs in three paired nonvalvular PAF patients with or without LRAF was investigated by high-throughput sequencing and validated by quantitative real-time polymerase chain reaction(q RT-PCR). Bioinformatics analyses, including Gene Ontology(GO), Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis, and circ RNA/mi RNA regulatory network, were performed to predict the functions and potential regulatory roles of differentially expressed(DE) circ RNAs.RESULTS A total of 12,834 circ RNAs, comprising 5,491 down-regulated and 7,343 up-regulated circ RNAs, were found to be DE in blood smaples from the two groups in peripheral blood between LRAF and non-recurrence control individuals. The most enriched GO categories in terms of molecular function, biological process, and cellular component features were catalytic activity,cellular metabolic process, and intracellular part, respectively. The KEGG enrichment study revealed that the most important metabolic process controlled by DE circ RNAs is endocytosis. In the circ RNA/micro RNAs interaction network, four up-regulated circ RNAs(hsa_circ_0002665, hsa_circ_0001953, hsa_circ_0003831, and hsa_circ_0040533) and one down-regulated circ RNA(hsa_circ_0041103) were predicted to play potential regulatory roles in the pathogenesis of LRAF.CONCLUSIONS This investigation discovered the expression pattern of circulating circ RNAs that is indicative of PAF late recurrence, which may serve as risk markers or therapeutic targets for LRAF after PVI.

Relationship between abnormal vagus nerve tension and basal ganglia cerebral infarction induced paroxysmal atrial fibrillation

Objective: To investigate the relationship between basal ganglia cerebral infarction and paroxysmal atrial fibrillation(PAF) caused by abnormal vagus nerve tension.Methods: A total of 1 483 cases of elder patients with cerebral infarction who received head CT or MRI examination during the period were enrolled, including 830 male and613 female, with the average age as 78 years. These cases were divided into basal infarction ganglia group(n = 1 045) and non-basal ganglia infarction group(n = 438)according to the anatomic site of cerebral infarction. The differences of the incidence of PAF, left atrial diameter and heart rate variability were compared between the two groups.Results: In basal ganglia infarction group, the incidence rate of PAF was significantly higher than that of non-basal ganglia infarction group(P < 0.05). The incidence trend of cerebral infarction in basal ganglia was age-related, in the >79 years basal ganglia cerebral infarction group, the incidence of PAF was significantly higher than that of nonbasal ganglia infarction group(P < 0.05). There was no significant difference in the left atrial diameter between the basal ganglia infarction group and non-basal ganglia infarction group. Basal ganglia cerebral infarction patients with high PAF had higher heart rate variability than non-basal ganglia infarction group.Conclusion: Elderly patients with basal ganglia infarction have high incidence of PAF.Sympathetic nerve damage in cerebral basal ganglia, increased vagal tension and cardiac vagal tension are the direct causes of PAF. The results indicates that the increased central vagal nerve tension mediated PAF probably is an indication of supplying sympathetic neurotransmitter or cardiac vagal denervation treatment.

Segmental radiofrequency ablation of pulmonary vein ostia for patients with refractory paroxysmal atrial fibrillation using multi-slice spiral computed tomography guidance

Objective： To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein （PV） ostia for patients with refractory paroxysmal atrial fibrillation （AF） under multi-slice spiral computed tomography （MSCT） guidance before the procedure. Methods： A series of 58 consecutive patients with refractory paroxysmal AF were enrolled to undergo segmental radiofrequency ablation ofPV ostia. The 36 male and 22 female patients with mean age of （57.4±9.5） （32-79） years and no obvious organic heart disease. Before ablation, patients received MSCT to generate 3-dimentional image of the left atrium （LA） and proximal PVs. Patients then underwent segmental radiofrequency ablation ofPV ostia using PV circular mapping catheter manipulated several times to ensure complete isolation between PVs and LA. Results： No complications occurred during the procedure. One patient developed delayed cardiac tamponade, which was drained percutaneously. The mean follow-up time was （17.1±9.3） months. Forty-one patients （95%） experienced improved quality of life one month after the procedure. Thirty-six patients （83%） showed stable sinus rhythm, while 10 patients （23%） required additional anti-arrhythmic drugs. AF returned≥1 time in 6 （14%） patients who underwent anti-arrhythmic drug therapy, but the number of episodes was less than that before the procedure. However, one patient experienced recurrent episodes of atrial flutter. Conclusion： It is safe and effective to perform segmental radiofrequency ablation of PV ostia for patients with refractory paroxysmal AF using MSCT guidance mappening.

Role of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in cryoballoon ablation outcomes for paroxysmal atrial fibrillation

BACKGROUND Cryoballoon ablation(CBA)is recommended for patients with paroxysmal atrial fibrillation(AF)refractory to antiarrhythmic drugs.However,only 80%of patients benefit from initial CBA.There is growing evidence that pretreatment with angiotensin-converting enzyme inhibitors(ACEIs)and angiotensin receptor blockers(ARBs)decreases the recurrence of AF postablation,particularly in nonparoxysmal AF undergoing radiofrequency ablation.The role of ACEIs and ARBs in patients with paroxysmal AF in CBA remains unknown.We decided to investigate the role of ACEIs and ARBs in preventing the recurrence of atrial arrhythmia(AA)following CBA for paroxysmal AF.AIM To investigate the role of ACEIs and ARBs in preventing recurrence of AA following CBA for paroxysmal AF.METHODS We followed 103 patients(age 60.6±9.1 years,29%women)with paroxysmal AF undergoing CBA 1-year post procedure.Recurrence was assessed by documented AA on electrocardiogram or any form of long-term cardiac rhythm monitoring.A multivariable Cox proportional hazard model was used to assess if ACEI or ARB treatment predicted the risk of AA recurrence.RESULTS After a 1-year follow-up,19(18.4%)participants developed recurrence of AA.Use of ACEI or ARB therapy was noted in the study population.Patients on ACEI/ARB had a greater prevalence of hypertension and coronary artery disease.On a multivariate model adjusted for baseline demographics and risk factors for AF,ACEI or ARB therapy did not prevent recurrence of AA following CBA(P=0.72).Similarly,on Kaplan–Meier analysis pretreatment with ACEI/ARB did not predict the time to first recurrence of AA(P=0.2173).CONCLUSION In our study population,preablation treatment with an ACEI or ARB had no influence on the recurrence of AA following CBA for paroxysmal AF.

QTc Interval Predicts Outcome of Catheter Ablation in Paroxysmal Atrial Fibrillation Patients with Type 2 Diabetes Mellitus

Catheter ablation has been recommended as a treatment option for paroxysmal atrial fibrillation（PAF） patients complicated with type 2 diabetes mellitus（T2DM）. PAF patients with T2 DM have a higher recurrence rate after catheter ablation. Prolongation of corrected QT（QTc） interval has been linked to poor outcomes in T2 DM patients. Whether the abnormal QTc interval is associated with the ablation outcome in the PAF patients with T2 DM remains unknown. In this study, 134 PAF patients with T2 DM undergoing primary catheter ablation were retrospectively enrolled. Pre-procedural QTc interval was corrected by using the Bazett＇s formula. Cox proportional hazards models were constructed to assess the relationship between QTc interval and the recurrence of AF. After a 29.1-month follow-up period, 61 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had a longer QTc interval than non-recurrent patients（425.2±21.5 ms vs. 414.1±13.4 ms, P=0.002）. Multivariate Cox regression analysis revealed that QTc interval [hazard ratio（HR）=1.026, 95% confidence interval（CI） 1.012–1.040, P=0.005] and left atrial diameter（LAD）（HR=1.125, 95% CI 1.062–1.192, P=0.003） were independent predictors of recurrent atrial tachyarrhythmia. Receiver operating characteristic analysis demonstrated that the cut-off value of QTc（418 ms） predicted arrhythmia recurrence with a sensitivity of 55.7% and a specificity of 69.9%. A combination of LAD and QTc was more effective than LAD alone（P〈0.001） in predicting arrhythmia recurrence after the procedure. QTc interval could be used as an independent predictor of arrhythmia recurrence in T2 DM patients undergoing AF ablation, thus providing a simple method to identify those patients who likely have a better outcome following the procedure.

Traditional Chinese Medicine nursing protocols for paroxysmal atrial fibrillation

Atrial fibrillation(AF), the most common cardiac arrhythmia worldwide, is associated with a higher risk of mortality and morbidity, in which paroxysmal atrial fibrillation(PAF) approximately accounts for 25%-60% of AF. Anti-arrhythmic drugs(AAD) have been used to treat different indications of AF for a long time, but its use is limited due to potential proarrhythmic cardiovascular and non-cardiovascular toxicity as well as the modest impact on the maintenance of sinus rhythm. Recently, Traditional Chinese Medicine(TCM) exhibits an excellent effect on PAF. This article primarily investigated the key points of common syndromes, TCM nursing methods and healthy guidance of PAF, aiming at maintaining and developing the strengths of TCM, improving its efficacy and standardizing its behavior.

Approach to Paroxysmal Atrial Fibrillation Type Arrhythmia in a Cardiology Service:A Case Report

Atrial fibrillation is a cardiac arrhythmia of high prevalence in the population, especially in the elderly. Its main electrical characteristics are the interval between two successive irregular R waves, absence of P waves and presence of f waves between QRS complexes. The most common symptoms of atrial fibrillation are irregular palpitations associated with dyspnea, dizziness, feeling tired, fatigue and general malaise, but not all patients have any symptoms. The present report presents the history of an elderly patient who arrived at the hospital’s emergency department with irregular heart rhythm and palpitations. The patient’s symptoms, associated with the electrocardiogram results, indicated paroxysmal atrial fibrillation. Electrical cardioversion was performed, and after, cardiac ablation via the femoral vein at the hospital’s cardiology service. There were no complications during the procedure. As a routine imaging exam after ablation, control esophagogastroduodenoscopy was requested to verify that there was no formation of atrio-esophageal fistula developed by the invasive ablation procedure and electrocardiogram, which showed normal sinus rhythm. The patient remained in the cardiac intensive care unit for observation for 24 hours. After the electrical cardioversion and catheter ablation procedures, the patient improved his clinical picture of atrial fibrillation and was discharged after 24 hours of hospitalization. He received treatment to perform at home, to reduce acid reflux into the esophagus and to prevent thrombosis. He did not present pulmonary thromboembolism after hospital discharge. It is believed, therefore, that this form of treatment and management of paroxysmal atrial fibrillation is effective for the solution of the proposed problem and can also serve as a reference for other professionals within the cardiology service.

DRUG THERAPY OF PAROXYSMAL ATRIAL FIBRILLATION IN THE ELDERLY OVER 75 YEARS OLD

Objective To investigate the effectiveness and safety of various agents on paroxysmal atrial fibrillation in the elderly over 75 years old.Methods Totally 264 in-patients (75-91 years old, 185 males and 79 females) with atrial fibrillation history of less than 7 days were enrolled in this study.A total of 611 atrial fibrillation episodes were recorded, but 130 episodes (22.3%) of atrial fibrillation were auto-converted to sinus rhythm.The rest 481 episodes of atrial fibrillation were divided into six groups based on the drug used.Results The cardioversion ratio of atrial fibrillation were 9.5%, 46.9%, 71.7%, 55.9%, 32.7%, and 73.6% in control, cedilanid, amiodarone, propafenone, verapamil, and quinidine groups, respectively.Ventricular rate control were 5.4%, 83.6%, 84.9%, 77.9%, 78.8%, and 11.3% in those groups, respectively.The total effective rates of amiodarone and cedilanid groups were the highest. When the ventricular rate was controlled to below 90 bpm, the patients would almost complain of no discomfort. No severe side-effect was observed in each group.Conclusion Amiodarone and cedilanid may be the proper drugs for the treatment of paroxysmal atrial fibrillation in the elderly.The above antiarrhythmics in each therapeutic group were relatively safe and effective.

Ultrasound ablation of pulmonary veins for treatment of paroxysmal atrial fibrillation

Objective : to evaluate the efficacy and safety of ultrasound ablation of pulmonary veins for treatment of paroxysmal atrial fibrillation. Methods : The study population consisted of 9 patients with 5 males and 4 females enrolled consecutively who had idiopathic paroxysmal atrial fibrillation(AF) . The ultrasound balloon was positioned through a special sheath to the orifice of the target vein by a transseptal procedure. The balloon was inflated with contrast-mixed saline (contrast: saline = 1:4) whose volume was decided by the diameter of the target pulmonary vein. The ablation energy was usually set up at 35 to 40 watts with temperature controlled at 60℃ . The duration of each ablation was about 120 seconds which was repeated not over 10 times. Results: The average duration of the total procedure was 132± 68 min for our patients. The average fluoroscopy time was 33 ±17 min. With a mean follow-up of 16 ±8 months after the procedure, AF was completely eliminated in 4 patients without antiarrhythmic drugs. The episodes of atrial fibrillation were eliminated in 2 patients with low dosage of oral amiodarone (0.1, once daily) which was ineffective before the procedure. The frequency of episodes was similar to that before the procedure in 3 patients. There were no complications such as hemopericardium, air embolism and stenosis of the pulmonary veins by angiography, related to the procedure. Conclusion : Ultrasound ablation of the pulmonary veins is a new approach to treat paroxysmal atrial fibrillation. Before we determined its value, we need to do more researches with bigger sample, randomization and comparison design.

Study on the mechanism of Renshen Gansong herb in the treatment of paroxysmal atrial fibrillation based on network pharmacology

Objective:To explore the target gene and mechanism of effective components of Renshen-Gansong in the treatment of paroxysmal atrial fibrillation based on network pharmacology.Methods:The chemical constituents of Renshen-Gansong drug pairs were searched by TCMSP traditional Chinese medicine database.The potentially effective components were screened under the conditions of bioavailability(OB)≥30%and drug-like(DL)≥0.18,and the potential targets were predicted by TCMSP database.The human gene name corresponding to the potential target was found by Uniprot database,and the disease target of paroxysmal atrial fibrillation was searched by Genecards database,the intersection target was mapped with the potential target of drug pair,the Wayne diagram was drawn,and the disease-drug-component-target network map was constructed by Cytoscape3.7.2.The PPI protein interaction network map was constructed by STRING database to select the core targets,and finally GO analysis and KEGG analysis were carried out.Results:A total of 28 active components and 45 effective targets were obtained.GO enrichment analysis showed that the main pathways were neurotransmitter receptor activity,ion gated channel activity,passive transmembrane transporter activity,G protein coupled neurotransmitter receptor activity and so on.KEGG pathway enrichment analysis showed that the main pathways were IL-17 signal pathway,calcium signal pathway,TNF signal pathway and so on.Conclusion:Renshen-Gansong has a synergistic effect on the treatment of paroxysmal atrial fibrillation through multi-targets,multi-pathways and multiple signal pathways,which provides a basis for further study of drug mechanism and clinical guidance.

Application Effect Evaluation of Telmisartan combined with Spironolactone after Catheter Ablation of Patients with Paroxysmal Atrial Fibrillation

Objective:To evaluate the application effect of telmisartan combined with spironolactone after catheter ablation of patients with paroxysmal atrial fibrillation.Methods:80 cases of patients with paroxysmal atrial fibrillation who received radiofrequency catheter ablation treatment from March 2013 to March 2016 in our hospital were randomly selected,these patients were divided into two groups according to the treatment methods,namely,the telmisartan with Spironolactone treatment group(combined treatment group,n=40)and the conventional therapy group(n=40).The hs-CRP,NT-proBNP,LAD and recurrence of the two groups were analyzed.Results:The hs-CRP,NT-proBNP levels after 3 months of the combined treatment group were significantly lower(P<0.05),the recurrence rate 10.0%(4/40)was significantly lower than the conventional therapy group 27.5%(11/40)(P<0.05),the time to recurrence was significantly longer than the conventional therapy group(P<0.05).Conclusion:The application effects of telmisartan combined with spironolactone after catheter ablation in the treatment of patients with paroxysmal atrial fibrillation are better than conventional therapy.

Effect of Statins on Preventing Paroxysmal Atrial Fibrillation after Pacemaker Implantation

Objective: To observe the effect of statins on preventing paroxysmal atrial fibrillation (PAF) after pacemaker imlantation in patients with sick sinus syndrome. Materials and Methods: 68 patients were selected in which the pacemakers had been implanted due to sick sinus syndrome,and were randomly divided into a statin treatment group and a control group. After the pacemaker implantation, only the patients in treatment group were given 20 mg atorvastatin once per night,with other conditions basically similar to those in the control group. At the 3rd, 9th, 15th, and 21st months after the implantation, the pacemakers were programmed, and the PAF-related information stored in the pacemaker were recalled and analyzed statistically. Results: After the administration of statins for 9 months since the imlantation, the occurrence rates of PAF in the treatment group was relatively lower than those in the control group. After further administration of statins for 15 months, both the occurrence rate of PAF and the burden of atrial fibrillation in the treatment group had significantly declined. After continuous administration of statins for 21 months, both the occurrence rate of PAF and the burden of atrial fibrillation in the treatment group were significantly lower than those in the control group. Conclusion: Long-term administration of statins can reduce the risk of PAF after the implantation of a pacemaker in patients with sick sinus syndrome.

Cryoballoon ablation on an elder paroxysmal atrial fibrillation patient implanted with double chamber pacemaker: a case report

Atrial fibrillation(AF)is the most common sustained cardiac arrhythmia,increasing in prevalence with age.Catheter ablation is recommended to symptomatic paroxysmal AF refractory or intolerant to at least one Class I or III antiarrhythmic medication.[1]Main current catheter ablation of AF with radiofrequency can give priority to,other include freezing,ultrasonic and laser ablation etc.Recent studies provides substantial information regarding the efficacy and safety of novel cryoballoon technology in creating pulmonary vein(PV)isolation.[2,3]Processed in cyroballoon ablation,some AF patients implanted with double chamber pacemaker are difficult to puncture atrial septal,because of the atrial electrode.My case report was as follows.

Prediabetes: An overlooked risk factor for major adverse cardiac and cerebrovascular events in atrial fibrillation patients

BACKGROUND Prediabetes is a well-established risk factor for major adverse cardiac and cerebrovascular events(MACCE).However,the relationship between prediabetes and MACCE in atrial fibrillation(AF)patients has not been extensively studied.Therefore,this study aimed to establish a link between prediabetes and MACCE in AF patients.AIM To investigate a link between prediabetes and MACCE in AF patients.METHODS We used the National Inpatient Sample(2019)and relevant ICD-10 CM codes to identify hospitalizations with AF and categorized them into groups with and without prediabetes,excluding diabetics.The primary outcome was MACCE(all-cause inpatient mortality,cardiac arrest including ventricular fibrillation,and stroke)in AF-related hospitalizations.RESULTS Of the 2965875 AF-related hospitalizations for MACCE,47505(1.6%)were among patients with prediabetes.The prediabetes cohort was relatively younger(median 75 vs 78 years),and often consisted of males(56.3%vs 51.4%),blacks(9.8%vs 7.9%),Hispanics(7.3%vs 4.3%),and Asians(4.7%vs 1.6%)than the non-prediabetic cohort(P<0.001).The prediabetes group had significantly higher rates of hypertension,hyperlipidemia,smoking,obesity,drug abuse,prior myocardial infarction,peripheral vascular disease,and hyperthyroidism(all P<0.05).The prediabetes cohort was often discharged routinely(51.1%vs 41.1%),but more frequently required home health care(23.6%vs 21.0%)and had higher costs.After adjusting for baseline characteristics or comorbidities,the prediabetes cohort with AF admissions showed a higher rate and significantly higher odds of MACCE compared to the non-prediabetic cohort[18.6%vs 14.7%,odds ratio(OR)1.34,95%confidence interval 1.26-1.42,P<0.001].On subgroup analyses,males had a stronger association(aOR 1.43)compared to females(aOR 1.22),whereas on the race-wise comparison,Hispanics(aOR 1.43)and Asians(aOR 1.36)had a stronger association with MACCE with prediabetes vs whites(aOR 1.33)and blacks(aOR 1.21).CONCLUSION This population-based study found a significant association between prediabetes and MACCE in AF patients.Therefore,there is a need for further research to actively screen and manage prediabetes in AF to prevent MACCE.

Atrial fibrillation and prediabetes:A liaison that merits attention!

Atrial fibrillation(AF)and prediabetes share common pathophysiological mechanisms with endothelial dysfunction and inflammation playing a key role.The resultant vicious cycle which sets in culminates in a higher atherogenicity and thermogenicity of the vascular system resulting in increased major adverse cardiac or cerebrovascular event(MACCE)events.However,the same has not convincingly been verified in real-world settings.In the recent retrospective study by Desai et al amongst AF patients being admitted to hospitals following MACCE,prediabetes emerged as an independent risk factor for MACCE after adjusting for all confounding variables.However,certain questions like the role of metformin,quantifying the risk for MACCE amongst prediabetes compared to diabetes,the positive impact of reversion to normoglycemia remain unanswered.We provide our insights and give future directions for dedicated research in this area to clarify the exact relationship between the two.

A three-pulmonary vein isolation approach to treat paroxysmal atrial fibrillation

Objective To investigate the safety and efficacy of a 3-pulmonary vein (PV) isolation approach in treating paroxysmal atrial fibrillation (AF). Methods Radiofrequency catheter ablation was used to eliminate PV potential in 11 patterns with frequent paroxysmal AF refractory to anti-arrhythmic agents. During sinus rhythm, PV potential was mapped in the left and right superior PVs and left inferior PV. The procedural success was defined as the elimination of PV potential in the 3 PVs. Restults PV potential was identified and abolished in a total of 24 PVs, mostly in the left and right superior PV. There was no pulmonary stenosis or other complications during or after the procedures. AF recurred in one patient after an average of 12 ± 3 month follow-up. Conclusions PV potemials were present mostly in the left or right superior PV. The 3-PVs isolation approach is safe and effective in preventing drug-resistant paroxysmal AF.

Experience with pulmonary vein isolation in patients with paroxysmal atrial fibrillation by using a circular cryoablation catheter

Objective This study was to report our early experience with electrical isolation of pulmonary vein (PV) in paroxysmal atrial fibrillation (AF) by using a circular cryoablation catheter. Methods After electroanatomic model of LA/PVs was established by Carto, cryoablation was performed in each PV. If complete isolation of PVs could not be achieved, then additional radiofrequency ablations would be applied to ablate the conduction gaps. Results Cryoablation was performed in totally 58 PVs in 14 cases with paroxysmal AF. Thirty-one PVs (53.4%) were successfully isolated with the single use of the circular cryoablation catheter after 2 to 5 (3.2±1.5) cryoablation, while 2 to 4 additional radiofrequency ablations needed to be applied at gaps on the circular cryoablation lines to achieve completely isolation in 27 PVs (46.6%). After a follow up of 18±7 months, 11 patients (78.6%) remained AF free. Selective pulmonary venography immediately and repeat magnetic resonance imaging (MRI) scan at 3 months post procedure showed there was no PV stenosis. Conclusion The circular cryoablation catheter can be safely used in the isolation of PVs in paroxysmal AF, But the efficacy of this technique needs to be further improved.

The correlation between gut microbiome and atrial fibrillation: pathophysiology and therapeutic perspectives

Regulation of gut microbiota and its impact on human health is the theme of intensive research.The incidence and prevalence of atrial fibrillation(AF)are continuously escalating as the global population ages and chronic disease survival rates increase;however,the mechanisms are not entirely clarified.It is gaining awareness that alterations in the assembly,structure,and dynamics of gut microbiota are intimately engaged in the AF progression.Owing to advancements in next-generation sequencing technologies and computational strategies,researchers can explore novel linkages with the genomes,transcriptomes,proteomes,and metabolomes through parallel meta-omics approaches,rendering a panoramic view of the culture-independent microbial investigation.In this review,we summarized the evidence for a bidirectional correlation between AF and the gut microbiome.Furthermore,we proposed the concept of“gut-immune-heart”axis and addressed the direct and indirect causal roots between the gut microbiome and AF.The intricate relationship was unveiled to generate innovative microbiota-based preventive and therapeutic interventions,which shed light on a definite direction for future experiments.

GLP-1 receptor agonists and myocardial metabolism in atrial fibrillation

Atrial fibrillation(AF)is the most common cardiac arrhythmia.Many medical conditions,including hypertension,diabetes,obesity,sleep apnea,and heart failure(HF),increase the risk for AF.Cardiomyocytes have unique metabolic characteristics to maintain adenosine triphosphate production.Significant changes occur in myocardial metabolism in AF.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)have been used to control blood glucose fluctuations and weight in the treatment of type 2 diabetes mellitus(T2DM)and obesity.GLP-1RAs have also been shown to reduce oxidative stress,inflammation,autonomic nervous system modulation,and mitochondrial function.This article reviews the changes in metabolic characteristics in cardiomyocytes in AF.Although the clinical trial outcomes are unsatisfactory,the findings demonstrate that GLP-1 RAs can improve myocardial metabolism in the presence of various risk factors,lowering the incidence of AF.

AV JUNCTION ELECTROPHYSIOLOGIC DATA IN PATIENTS HAVING PAROXYSMS OF ATRIAL FIBRILLATION

The aim of the study was to investigate peculiarities of AV junctionconduction in paroxysmal atrial fibrillation（AF）pts.We retrospectively assessed electrophysiologic investigations data in53 pts having paroxysmal AF.Assessment of the AV junctionconduction was performed during rapid and programmed stimulationin the setting of sinus thythm.Sixteen（30.1%）pts were revealed tohave signs of longitudinal dissociation of AV conduction which wascharacteristic of suddenly increased A2-H2 interval by more than 50msThe remaining pts did not reveal dual AV conduction pathways.Tenpts revealed polyfascicular antegrade AV conduction and distallydisturbed conduction which was manifested by the lengthened H2-V2interval to 70-150 ms during programmed stimulation performed fromthe sinoatrial zone.These pts had ventricular contractions rate of118±16.4/min in the setting AF both spontaneously induced andinduced by the stimulation which were reliably（p【0.05）lesscompared to other pts（168.6±29.4/min）.Thirty three（62.2%）pts whohad no multiple AV conducting pathways revealed distally slowed（to40-60 ms）conductionas well.Thus 92.5% of pts having AF paroxysms revealed concealed AVconduction disturbance and 30.2% revealed polyfascicular one.Wedid not reveal marked tachysystole in pts having multiple AVconduction pathways and distally disturbed conduction which must betaken into account while performing modification of the AVconduction in these pts.