Assessment of atrial electromechanical delay and P-wave dispersion in patients with type 2 diabetes mellitus

Transcriptomic analysis of epicardial adipose tissue reveals the potential crosstalk genes and immune relationship between type 2 diabetes mellitus and atrial fibrillation

BACKGROUND

The complex relationship between atrial fibrillation (AF) and type 2 diabetes mellitus (T2DM) suggests a potential role for epicardial adipose tissue (EAT) that requires further investigation. This study employs bioinformatics and experimental approaches to clarify EAT's role in linking T2DM and AF, aiming to unravel the biological mechanisms involved.

METHOD

Bioinformatics analysis initially identified common differentially expressed genes (DEGs) in EAT from T2DM and AF datasets. Pathway enrichment and network analyses were then performed to determine the biological significance and network connections of these DEGs. Hub genes were identified through six CytoHubba algorithms and subsequently validated biologically, with further in-depth analyses confirming their roles and interactions. Experimentally, db/db mice were utilized to establish a T2DM model. AF induction was executed via programmed transesophageal electrical stimulation and burst pacing, focusing on comparing the incidence and duration of AF. Frozen sections and Hematoxylin and Eosin (H&E) staining illuminated the structures of the heart and EAT. Moreover, quantitative PCR (qPCR) measured the expression of hub genes.

RESULTS

The study identified 106 DEGs in EAT from T2DM and AF datasets, underscoring significant pathways in energy metabolism and immune regulation. Three hub genes, CEBPZ, PAK1IP1, and BCCIP, emerged as pivotal in this context. In db/db mice, a marked predisposition towards AF induction and extended duration was observed, with HE staining verifying the presence of EAT. Additionally, qPCR validated significant changes in hub genes expression in db/db mice EAT. In-depth analysis identified 299 miRNAs and 33 TFs as potential regulators, notably GRHL1 and MYC. GeneMANIA analysis highlighted the hub genes' critical roles in stress responses and leukocyte differentiation, while immune profile correlations highlighted their impact on mast cells and neutrophils, emphasizing the genes' significant influence on immune regulation within the context of T2DM and AF.

CONCLUSION

This investigation reveals the molecular links between T2DM and AF with a focus on EAT. Targeting these pathways, especially EAT-related ones, may enable personalized treatments and improved outcomes.

Study of P wave dispersion in patients with paroxysmal atrial fibrillation and its role in prediction of atrial fibrillation recurrence

BACKGROUND

It has been known that increased P wave duration and P wave dispersion reflect prolongation of intra-atrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses, which are well-known electrophysiologic characteristics in patients with atrial arrhythmias and especially paroxysmal atrial fibrillation. The objective of this study was assessment of P wave dispersion value in cases with paroxysmal atrial fibrillation and its role in predicting recurrence.

RESULTS

Forty-eight patients with documented paroxysmal AF were subjected to clinical evaluation, electrocardiogram and routine Doppler echocardiogram. We found that a statistically significant association was detected between P wave dispersion and older age, diabetic and hypertensive cases with positive correlation also detected with left atrial dimension (LAD), left ventricle size and diastolic dysfunction grade. Mean corrected P wave dispersion and corrected QT interval were higher among cases using sotalol, ca channel blockers, among cases using nitrates and among cases with Morris index > 0.04. Higher mean value of corrected QT was associated with biphasic P v1 shape. Old age, female sex, P wave dispersion and QT wave dispersion are statistically significant predictors of PAF recurrence.

CONCLUSION

P wave dispersion in patients with paroxysmal atrial fibrillation was strongly correlated to older age, diabetic and hypertensive patients and also with left atrial dimension (LAD), left ventricle size and diastolic dysfunction grade. Also, mean corrected P wave dispersion can predict atrial fibrillation recurrence in patients with Morris index > 0.04, old age, female sex, and QT wave dispersion.

β-blockades and the risk of atrial fibrillation in patients with cardiovascular diseases

Background

β-blockers have been widely used in patients with extensive cardiovascular disease (CVD) and have provided benefits. However, they are more likely to cause symptomatic bradycardia, hypotension, or glucose metabolism disorders, which may lead to an increased risk of atrial fibrillation (AF), but evidence is lacking.

Aims

This study was to analyze the association between the use of β-blockers and the risk of developing AF.

Methods

This nationwide, prospective cohort study utilized data from the 2013-2020 National Health and Nutrition Examination Survey (NHANES). The patients were stratified into a β-blocker treatment group (n = 2585) and a non-β-blocker treatment group (n = 8525). Univariate and multivariate logistic regression analyses were performed to identify the relationship between β-blockades and the risk of AF. Propensity matching analysis was used to balance patient baseline characteristics and to control for confounders.

Results

A total of 11,110 subjects were included in this study (mean [SD] age, 59.89 [15.07] years; 5657 [49.7%] males). A total of 111/2585 subjects developed AF in the β-blocker treatment group, and 75/8525 developed AF in the non-β-blocker treatment group (incidence rate, 4.2% vs. 0.8%). Compared with the non-β-blocker group, the β-blocker group had an increased risk of incident AF (aOR, 2.339; 95% CI, 1.614-3.410). Some sensitivity analyses also revealed consistent findings of increased AF risk associated with β-blocker treatment.

Conclusion

The findings from this study suggest that β-blocker treatment is associated with an increased risk of incident AF and may help physicians select a modest medication for patients while also assessing the risk of AF.

The Effect of Glycemic Status on P Wave Dispersion

Background and aim The growing number of people with diabetes mellitus (DM) across the world is a public health concern. The diabetes epidemic involves enormous health costs to the patients, their careers, and society at large. Cardiovascular diseases such as atrial fibrillation (AF) often develop in the diabetic population. An increase in the P wave dispersion (PWD) has been established as an independent risk factor for the occurrence of AF, hence the present study was conducted to establish a possible relationship between PWD and the glycemic status of the individual to predict the occurrence of AF ahead of clinical symptomology. Methodology A comparative cross-sectional study was conducted at a tertiary care hospital after obtaining approval from the institutional ethics committee and written consent of each study subject. The main steps included the selection and categorization of the study population based on their glycemic status, collection of demographic data, performing ECGs calculating PWD using digital calipers, and recording the data systematically for evaluation. Results In this study, 234 patients with a mean age of 53.3 ± 13.1 years were studied, of which 121 (51.7%) were male and 113 (48.29%) were female. The 234 patients were divided into four groups based on their glycemic status - 74 uncontrolled DM patients (31.62%), 51 type 2 DM (T2DM) patients (21.78%), 56 prediabetes patients (23.93%), and 53 patients in the control group (22.64%; not a known case of diabetes with normal HbA1c and fasting blood sugar (FBS) levels). Minimal correlation was observed between FBS with PWD (r value 0.175) and age with PWD (r value 0.161), but statistical significance was observed only between age and PWD (p-value 0.014). The difference in means between the four different study groups was found to be not statistically significant (p-value- 0.104); hence, no intergroup variation was noted. Conclusion Advancing age and higher fasting blood sugars have shown minimal correlation with widening P-wave dispersion. With further studies involving larger populations, this can be a promising aid in identifying PWD as a probable early predictor of atrial arrhythmias among diabetic patients.

Left atrial cardiomyopathy: Pathophysiological insights, assessment methods and clinical implications

Atrial cardiomyopathy is defined as any complex of structural, architectural, contractile or electrophysiological changes affecting atria, with the potential to produce clinically relevant manifestations. Most of our knowledge about the mechanistic aspects of atrial cardiomyopathy is derived from studies investigating animal models of atrial fibrillation and atrial tissue samples obtained from individuals who have a history of atrial fibrillation. Several noninvasive tools have been reported to characterize atrial cardiomyopathy in patients, which may be relevant for predicting the risk of incident atrial fibrillation and its related outcomes, such as stroke. Here, we provide an overview of the pathophysiological mechanisms involved in atrial cardiomyopathy, and discuss the complex interplay of these mechanisms, including aging, left atrial pressure overload, metabolic disorders and genetic factors. We discuss clinical tools currently available to characterize atrial cardiomyopathy, including electrocardiograms, cardiac imaging and serum biomarkers. Finally, we discuss the clinical impact of atrial cardiomyopathy, and its potential role for predicting atrial fibrillation, stroke, heart failure and dementia. Overall, this review aims to highlight the critical need for a clinically relevant definition of atrial cardiomyopathy to improve treatment strategies.

Unveiling the Role of Endothelial Dysfunction: A Possible Key to Enhancing Catheter Ablation Success in Atrial Fibrillation

Atrial fibrillation, a prevalent type of arrhythmia, is increasingly contributing to the economic burden on healthcare systems. The development of innovative treatments, notably catheter ablation, has demonstrated both impressive and promising outcomes. However, these treatments have not yet fully replaced pharmaceutical approaches, primarily due to the relatively high incidence of atrial fibrillation recurrence post-procedure. Recent insights into endothelial dysfunction have shed light on its role in both the onset and progression of atrial fibrillation. This emerging understanding suggests that endothelial function might significantly influence the effectiveness of catheter ablation. Consequently, a deeper exploration into endothelial dynamics could potentially elevate the status of catheter ablation, positioning it as a primary treatment option for atrial fibrillation.

Metabolic Syndrome and Atrial Fibrillation: Different Entities or Combined Disorders

Obesity, hypertension, insulin resistance, and dyslipidemia are all clusters of an entity called "Metabolic Syndrome". The global trends of this syndrome's incidence/prevalence continue to increase reciprocally, converting it into a massive epidemic problem in the medical community. Observing the risk factors of atrial fibrillation, a medical condition that is also converted to a scourge, almost all parts of the metabolic syndrome are encountered. In addition, several studies demonstrated a robust correlation between metabolic syndrome and the occurrence of atrial fibrillation. For atrial fibrillation to develop, a combination of the appropriate substrate and a trigger point is necessary. The metabolic syndrome affects the left atrium in a multifactorial way, leading to atrial remodeling, thus providing both the substrate and provoking the trigger needed, which possibly plays a substantial role in the progression of atrial fibrillation. Due to the remodeling, treatment of atrial fibrillation may culminate in pernicious sequelae, such as repeated catheter ablation procedures. A holistic approach of the patient, with simultaneous treatment of both entities, is suggested in order to ensure better outcomes for the patients.

Diabetes mellitus and atrial fibrillation-from pathophysiology to treatment

Type 2 diabetes mellitus (T2DM) is a leading risk factor for cardiovascular complications around the globe and one of the most common medical conditions. Atrial fibrillation (AF) is the most common supraventricular arrhythmia, with a rapidly increasing prevalence. T2DM has been closely associated with the risk of AF development, identified as an independent risk factor. Regarding cardio-vascular complications, both AF and T2DM have been linked with high mortality. The underlying pathophysiology has not been fully determined yet; however, it is multifactorial, including structural, electrical, and autonomic pathways. Novel therapies include pharmaceutical agents in sodium-glucose cotransporter-2 inhibitors, as well as antiarrhythmic strategies, such as cardioversion and ablation. Of interest, glucose-lowering therapies may affect the prevalence of AF. This review presents the current evidence regarding the connection between the two entities, the pathophysiological pathways that link them, and the therapeutic options that exist.

Effect of SGLT-2 inhibitors as an add-on therapy to metformin on P wave indices and atrial electromechanics in type 2 diabetes mellitus patients

INTRODUCTION

Sodium-glucose co-transporter 2 (SGLT-2) inhibitors have been shown to reduce the risk of atrial fibrillation (AF) occurrence in patients with diabetes mellitus (DM). In this prospective study, we aimed to analyze the effect of SGLT-2 inhibitors as an add-on therapy to metformin on P wave indices and atrial electromechanics in patients with type 2 DM.

METHODS

A total of 144 patients enrolled. Electrocardiographic indices were recorded on admission and at 3rd and 6th month of the combination therapy. P wave indices and atrial electromechanical coupling intervals were measured and compared.

RESULTS

Although decrease in P wave dispersion (62.78 ± 9.59 vs. 53.62 ± 10.65; p = .002) became significant at 6th month of combination therapy, significant decreases in P wave terminal force in V₁ (37.79 ± 3.45 vs. 32.01 ± 5.74; p = .035), left atrial volume index (35.87 ± 6.57 vs. 31.33 ± 7.31; p = .042), left sided intra-atrial electromechanical delay (32.09 ± 9.17 vs. 27.61 ± 8.50; p = .016), right sided intra-atrial electromechanical delay (31.82 ± 4.92 vs. 27.65 ± 8.05; p = .042), and interatrial electromechanical delay (29.65 ± 7.52 vs. 25.96 ± 4.30; p = .044) were seen as early as 3rd month of treatment. Besides, there was no statistically significant difference between Empagliflozin and Dapagliflozin subgroups in terms of mentioned parameters.

CONCLUSION

SGLT-2 inhibitors as an add-on therapy to metformin were shown to significantly improve P wave indices and atrial electromechanics in type 2 DM patients as early as the 3rd month of treatment. It was thought that this may be one of the underlying mechanisms of the decrease in the frequency of AF with the use of SGLT2 inhibitors.

Electrocardiographic and Echocardiographic Predictors of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

Background

Patients with hypertrophic cardiomyopathy (HCM) have an increased prevalence of atrial fibrillation (AF) compared to the general population, and left atrium (LA) remodeling is strongly correlated with the risk of AF. This prospective, monocentric study aimed to assess the role of LA electrocardiographic and echocardiographic (structural and functional) parameters in predicting the risk for incident AF in patients with HCM.

Methods and Results

The study population consisted of 126 HCM patients in sinus rhythm (52.6 ± 16.2 years, 54 men), 118 of them without documented AF. During a median follow-up of 56 (7–124) months, 39 (30.9%) developed a new episode of AF. Multivariable analysis showed that LA booster pump function (assessed by ASr, HR = 4.24, CI = 1.84–9.75, and p = 0.038) and electrical dispersion (assessed by P wave dispersion – Pd, HR = 1.044, CI = 1.029–1.058, and p = 0.001), and not structural parameters (LA diameter, LA volume) were independent predictors of incident AF. Seventy-two patients had a LA diameter < 45 mm, and 16 of them (22.2%) had an AF episode during follow-up. In this subgroup, only Pd emerged as an independent predictor for incident AF (HR = 1.105, CI = 1.059–1.154, and p = 0.002), with good accuracy (AUC = 0.89).

Conclusion

Left atrium booster pump function (ASr) and electrical dispersion (Pd) are related to the risk of incident AF in HCM patients. These parameters can provide further stratification of the risk for AF in this setting, including in patients considered at lower risk for AF based on the conventional assessment of LA size.

Mechanisms underlying electro-mechanical dysfunction in the Zucker diabetic fatty rat heart: a model of obesity and type 2 diabetes

Diabetes mellitus (DM) is a major and worsening global health problem, currently affecting over 450 million people and reducing their quality of life. Type 2 diabetes mellitus (T2DM) accounts for more than 90% of DM and the global epidemic of obesity, which largely explains the dramatic increase in the incidence and prevalence of T2DM in the past 20 years. Obesity is a major risk factor for DM which is a major cause of morbidity and mortality in diabetic patients. The electro-mechanical function of the heart is frequently compromised in diabetic patients. The aim of this review is to discuss the pathophysiology of electro-mechanical dysfunction in the diabetic heart and in particular, the Zucker diabetic fatty (ZDF) rat heart, a well-studied model of T2DM and obesity.

Early cardiac electrical and structural changes in patients with non-obese non-alcoholic fatty liver disease

Background    Obese non-alcoholic fatty liver disease (NAFLD) was found to increase the risk of developing atrial fibrillation (AF) regardless of the metabolic syndrome subgroups that may accompany it. In this study, the effect of NAFLD on the structural and electrical functions of the heart was investigated using tissue Doppler echocardiography (TDE) in non-obese NAFLD patients without any known risk factors for AF.Material and methods    The study included 43 female patients (31.3±3.8 years), who had stage 2-3 hepatosteatosis detected by liver ultrasonography and diagnosed as non-obese NAFLD (patient group), and 31 healthy women (control group, 32.5±3.6 years). In addition to standard echocardiographic parameters, inter- and intra-atrial electromechanical delay (EMD) were evaluated by TDE.Results    Interatrial EMD (PA lateral - PA tricuspid) and intraatrial EMD (PA septum - PA tricuspid) were significantly longer in patient group (16.1±3.4 vs. 12.5±2.3 ms, p<0.001, and 8.4±1.6 vs. 6.6±1.6 ms, p<0.001, respectively). At the subclinical level. atrial size, left ventricular diastolic function, and left ventricular wall thickness measurements were greater in the patient group.Conclusion    Inter-atrial and intra-atrial EMD were detected in young women with non-obese NAFLD. In addition, at the subclinical level, structural and functional impairment was detected However, large-volume prospective studies are required to cobfirm these findings regarding the development of AF in non-obese NAFLD patients.

Vectorial theory surpasses the local theory in explaining the origin of P-wave dispersion

BACKGROUND

Local theory and the vectorial theory are used to explain the origin of P-wave dispersion (PWD). There are no previous studies that analyze both at the same time.

OBJECTIVES

We set out to determine the implication of local and vectorial theories in the origin of PWD.

METHODS

Cross-sectional study in 153 randomly selected patients aged 18-70 years, undergoing electrophysiological study. Inhomogeneous atrial conduction was evaluated by atrial electrogram dispersion in terms of duration (EGM_durdis) and morphology (EGM_morph dis). P-distal coronary sinus interval (P-DCS) was also measured. P-wave was measured twice, firstly at a calibration of 20 mm/mV and a sweep speed of 50 mm/s, enhancement 10× (basic measurement [BM]), and second time at sweep speed of 150 mm/s, enhancement 80-160× (high precision measurement [HPM]).

RESULTS

PWD with BM was 48 ms [36-54 ms] while with HPM it was 4 ms [0-10 ms], p < 0.001. With BM, maximum and minimum P- wave duration presented a moderate correlation (r = 0.342; p < 0.001), using HPM it becomes strong (r = 0.750; p < 0.001). In cases with P-DCS < 80 ms (r = 0.965; p < 0.001), but not with P-DCS ≥ 80 ms (r = 0.649; p < 0.001), the previous correlation became almost perfect with HPM. EGM_durdis and EGM_morphdis were weak but significantly correlated with PWD. This correlation became moderate in patients with P-DCS ≥ 80 ms and disappeared in those with P-DCS, using BM and HPM.

CONCLUSION

Vectorial theory explains almost entirely the PWD phenomenon. Inhomogeneous conduction could be an additional mechanism to explain PWD, but its contribution is small.

Treatment Effect of Type 2 Diabetes Patients in Outpatient Department Based on Blockchain Electronic Mobile Medical App

As the pace of people's lives accelerates, there are more and more diabetic patients. This research mainly explores the treatment effect of type 2 diabetic patients based on blockchain electronic mobile medical app. Considering that it is more realistic to adopt an off-chain storage solution, the blockchain-based medical data sharing platform in this study adopts an off-chain storage solution. Only key information is stored in the blockchain network, and all medical data will be in the cloud space. For storage, cloud storage uses Aliyun's OSS storage service, which can be expanded infinitely. The cloud operation module is responsible for all operations that interact with cloud storage. The chain code can call the cloud operation module to upload the user's encrypted medical data and user ID to Alibaba Cloud's OSS. The chain code will return the storage address of the medical data and the authorized access address is sent to the blockchain network for consensus on the chain. The message processing module provides information processing functions such as chat information processing, APP use reminders, and health tips. The indicator recording module includes indicator recording functions including 6 indicators of blood sugar, medication, diet, weight, exercise, and sleep. The main function of the indicator analysis module is to display the curve trends of the 6 indicators recorded by the patient in three days, one week, and one month. Comparing the change range of the mean value of glycosylated hemoglobin at the beginning and end of the two groups of patients, it can be found that the change range of glycosylated hemoglobin in the intervention group is -6.04%, while the change range of the control group is only -3.26%. The impact of the mobile medical app designed in this study will indeed be reflected in the patient's blood sugar control and help patients to better control blood sugar.

Assessment of Hypertension Using Clinical Electrocardiogram Features: A First-Ever Review

Hypertension affects an estimated 1.4 billion people and is a major cause of morbidity and mortality worldwide. Early diagnosis and intervention can potentially decrease cardiovascular events later in life. However, blood pressure (BP) measurements take time and require training for health care professionals. The measurements are also inconvenient for patients to access, numerous daily variables affect BP values, and only a few BP readings can be collected per session. This leads to an unmet need for an accurate, 24-h continuous, and portable BP measurement system. Electrocardiograms (ECGs) have been considered as an alternative way to measure BP and may meet this need. This review summarizes the literature published from January 1, 2010, to January 1, 2020, on the use of only ECG wave morphology to monitor BP or identify hypertension. From 35 articles analyzed (9 of those with no listed comorbidities and confounders), the P wave, QTc intervals and TpTe intervals may be promising for this purpose. Unfortunately, with the limited number of articles and the variety of participant populations, we are unable to make conclusions about the effectiveness of ECG-only BP monitoring. We provide 13 recommendations for future ECG-only BP monitoring studies and highlight the limited findings in pregnant and pediatric populations. With the advent of convenient and portable ECG signal recording in smart devices and wearables such as watches, understanding how to apply ECG-only findings to identify hypertension early is crucial to improving health outcomes worldwide.

Atrial conduction explains the occurrence of the P-wave dispersion phenomenon, but weakly

BACKGROUND

P-wave dispersion (PWD) is believed to be caused by inhomogeneous atrial conduction. This statement, however, is based on limited little solid evidence. The aim of this study was to determine the relationship between atrial conduction and PWD by means of invasive electrophysiological studies.

METHODS

Cross-sectional study in 153 patients with accessory pathways and atrioventricular node reentry tachycardia (AVNRT) undergoing an electrophysiological study. Different atrial conduction times were measured and correlated with PWD.

RESULTS

Only the interatrial (P-DCS) and left intra-atrial conduction times (ΔDCS-PCS) showed a significant correlation with PWD, but this correlation was weak. Multivariate linear regression analysis determined that both P-DCS (β = 0.242; P = .008) and ΔDCS-PCS (β = 0.295; P < .001) are independent predictors of PWD. Performing the multivariate analysis for arrhythmic substrates, it is observed that only ΔDCS-PCS continued to be an independent predictor of PWD. Analysis of the receiver operating characteristic curves showed that regardless of the types of arrhythmic substrates, PWD discriminates significantly, but moderately, to patients with P-DCS and ΔDCS-PCS ≥75 percentile.

CONCLUSIONS

Interatrial and intraleft atrial conduction times were directly and significantly correlated with PWD, but only weakly, and were independent predictors of PWD. In general, PWD correctly discriminates patients with high values in interatrial and intraleft atrial conduction times, but moderately. This is maintained in cases with accessory pathways; however, in patients with AVNRT it only does so for intraleft atrial conduction times. Interatrial and intraleft atrial conduction times weakly explains PWD.

Determinants of left intra-atrial electromechanical delay as evaluated by tissue Doppler imaging in candidates for coronary artery bypass graft surgery

OBJECTIVES

Inhomogeneity in the atrial conduction time is a predisposing factor for atrial fibrillation. The aim of our study was to determine the independent determinants of the left intra-atrial electromechanical delay (LIAEMD) as a marker of left atrial (LA) dyssynchrony in candidates for coronary artery bypass graft surgery (CABGS).

METHODS

This prospective cross-sectional study recruited 516 consecutive candidates for CABGS. Via the pulsed-wave tissue Doppler imaging modality in echocardiography, the times between the P wave and the peak of the a' wave at the septal and lateral mitral annuli were measured and the difference between these times was considered to be LIAEMD. Additionally, clinical and laboratory data on each patient were gathered. The odds ratio for an increased LIAEMD was calculated in patients with and without diabetes in univariate and multivariate analyses.

RESULTS

The multivariable analysis revealed that in the patients without diabetes, obesity, calcium-channel blocker usage, an increased maximal LA volume, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio were independently correlated with an increased likelihood of LIAEMD occurrence (P < .05).

CONCLUSIONS

In our study on CABGS candidates, in the patients without diabetes, obesity, an increased maximal LA volume, calcium-channel blocker usage, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio independently determined increased LIAEMD. The prevention or treatment of factors that are detrimental to the LA electromechanical function may be helpful for the preservation of the LA electromechanical integrity.

Impact of Transcatheter Device Closure of Atrial Septal Defect on Atrial Arrhythmias Propensity in Young Adults

Atrial septal defect (ASD) is a condition that requires early intervention because of the consequences over the right-side heart. Chronic atrial stretching promotes atrial conduction delay and the imbalance of the conduction homogeneity, which lead to the propensity to atrial arrhythmias (AA). We aim to evaluate the impact of transcatheter closure of ASD on atrial vulnerability markers leading to late AA in young adults. We conducted a prospective, longitudinal study in one hundred patients (mean age 25.2 ± 5.4 years) who underwent transcatheter closure of ASD at Cardiocentro Pediátrico William Soler. P-wave maximum (P_max) and P-wave dispersion (P_d) were analyzed from 12-lead electrocardiogram. Left-side and right-side intraatrial and interatrial electromechanical delay (EMD) were measured with tissue Doppler imaging. Both electrocardiographic and echocardiographic analyses were performed during the study period. Compared to baseline, there was a significant reduction in P max (p ≤ 0.001) and P_d (p ≤ 0.001) after 3 months of procedure. All atrial electromechanical coupling parameters significantly reduced at 6 months of ASD closure and tend to remain at lower values till the last evaluation. Over 9.2 ± 1.6 years of follow-up, 15 subjects (15%) developed AA, of which intraatrial reentrant tachycardia (66.6%) became the main rhythm disturbance. Intra-right atrial EMD ≥ 16 ms (HR 4.08, 95% CI 1.15-14.56; p = 0.03) and P_d 45 ms (HR 1.66, 95% CI 1.06-2.59; p = 0.02) were identified as predictors of late AA. Transcatheter device closure of ASD in young adults promotes a significant reduction of electrocardiographic and echocardiographic markers of AA vulnerability, which persist during the long-term follow-up. Nevertheless, P_d and interatrial EMD were identified as independent risk factors of AA.

Glycemic control is associated with atrial structural remodeling in patients with type 2 diabetes

Background

Diabetes mellitus (DM) has been demonstrated to be a strong risk factor for development and perpetuation of atrial fibrillation (AF). However, how DM and glycemic control affect the pathogenesis of AF has not been sufficiently investigated, especially for the atrial structural remodeling.

Methods

A total of 86 patients undergoing coronary artery bypass graft surgery were enrolled in this study, with atrium sample collected in the operation. The patients were divided into the DM group (n = 40) and the control group (n = 46) accordingly. Demographics, clinical data were collected and compared. Echocardiography, Masson staining and Western blotting were conducted to evaluate atrial structural remodeling.

Results

There was no significant difference between the two groups in baseline characteristics (all P > 0.05). Fast blood glucose and HbA1c of DM group were significantly higher than the control group (P < 0.001). Echocardiography results demonstrated that the left atrium diameter (LAD) and left atrium volume index (LAVI) of DM group was significantly higher than the control group (P < 0.001). Masson staining showed that the collagen volume fraction (CVF), a quantitative indicator of fibrosis, was significantly higher in DM patients (P = 0.03). Western blot results indicated that the Collagen I of DM group was more expressed in the DM group than the control group (P < 0.001). Univariate linear regression revealed that the HbA1c level was significantly associated with both LAD (Y = 1.139X + 25.575, P < 0.001, R² = 0.291) and CVF (Y = 0.444X + 29.648, P = 0.009, R² = 0.078).

Conclusions

DM was associated with atrial structural remodeling, including atrium enlargement and atrial fibrosis, which might be attributed to poor glycemic control.

Assessment of Subclinical Cardiac Alterations and Atrial Electromechanical Delay by Tissue Doppler Echocardiography in Patients with Nonfunctioning Adrenal Incidentaloma

Background

Majority of the incidentally discovered adrenal masses, called adrenal incidentaloma (AI), are nonfunctioning adrenal adenomas. The appropriate management of AI is still a matter debate, so it is necessary to investigate their associated morbidity. However, data regarding morphological and functional cardiac alterations are limited in this group.

Objective

In this study, we aimed to assess cardiac structural and functional characteristics and atrial conduction properties in patients with nonfunctioning AI.

Methods

Thirty patients with nonfunctioning AI and 46 properly matched control subjects were included in the study. After hormonal and biochemical analysis, all participants underwent transthoracic echocardiography to obtain systolic and diastolic parameters of both ventricles, in addition to atrial conduction times by tissue Doppler echocardiography. Data were analyzed with Statistical Package for the Social Sciences (SPSS, Chicago, IL, United States) statistics, version 17.0 for Windows. P < 0.05 was considered statistically significant.

Results

Left ventricular (LV) mass index and LV myocardial performance index were significantly increased in AI group. Among atrial conduction times, both intra- and interatrial electromechanical delays were significantly prolonged in patients with nonfunctioning AI. Other laboratory and echocardiographic findings were similar between groups.

Conclusion

Our study revealed that intra- and inter-atrial conduction times were prolonged, and LV mass index was increased in patients with nonfunctioning AI. These findings may be markers of subclinical cardiac involvement and tendency to cardiovascular complications. Close follow-up is necessary for individuals with nonfunctioning AI for their increased cardiovascular risk.

Assessment of atrial conduction times in prediabetic patients with coronary artery disease

Objective:

Prediabetes is a dysglycemic state and is associated with subtle myocardial injury and dysfunction. We evaluated atrial conduction times (ACTs) and atrial electromechanical delays (EMDs) in prediabetic patients with coronary artery disease (CAD).

Methods:

In the present study, we recruited 128 consecutive patient candidates (40 euglycemic, 48 prediabetic, and 40 diabetic patients) for coro- nary artery bypass grafting. ACTs were measured using tissue Doppler imaging (TDI). The time intervals between the beginning of the P wave in the surface electrocardiogram and the peak of the a¢ wave in TDI (PA) in the septal and lateral mitral annuli and the lateral tricuspid annulus were measured and termed as “septal PA,” “lateral PA,” and “right ventricular (RV) PA,” respectively. The differences between lateral and septal PA, septal and RV PA, and lateral and RV PA were termed as “left intra-atrial EMD,” “right intra-atrial EMD,” and “inter-atrial EMD” respectively.

Results:

Septal PA, lateral PA, RV PA, left and right intra-atrial EMDs, and inter-atrial EMD were not statistically different between these three groups. Furthermore, multivariable linear regression models, adjusted for potential confounders, showed that glycemic state was not associated with ACTs, left and right intra-atrial EMDs, and inter-atrial EMD.

Conclusion:

There were no significant differences between the euglycemic, prediabetic, and diabetic patients with CAD regarding ACTs and atrial EMDs.

P-wave dispersion: an update

P-wave dispersion (PWD, Pd or Pdis) is a noninvasive electrocardiographic (ECG) marker for atrial remodeling and predictor for atrial fibrillation (AF). PWD is defined as the difference between the widest and the narrowest P-wave duration recorded from the 12 ECG leads. Increased P-wave duration and PWD reflect prolongation of intraatrial and interatrial conduction time with lack of a well-coordinated conduction system within the atrial muscles, with inhomogeneous, asynchronic, pro-inflammatory and anti-inflammatory effect mediated by interleukin-6 (IL-6) in patients with the CG + GG genotype IL-6 -634C/G polymorphism [1] and discontinuous propagation of sinus impulses mainly between the left and right atria, interstitial/extracellular fibroblast activation and collagen deposition with fibrosis (via TGF-β) in atrial tissue, insufficient blood supply, significant not isotropic myoelectric activity, and thin wall thickness and consequent expansion tendency all well-known electrophysiological characteristics in patients with atrial arrhythmias and especially paroxysmal atrial fibrillation (PAF) [2].

Atrial electromechanical delay and left atrial mechanical functions in hemodialysis and peritoneal dialysis patients

INTRODUCTION

Left atrium (LA) mechanical functions and atrial electromechanical delay (AEMD) times were considered independent predictors of cardiovascular morbidity in general population. Data are scant about these parameters in end-stage renal disease (ESRD) patients receiving hemodialysis (HD) and peritoneal dialysis (PD). We aimed to evaluate AEMD times and LA mechanical functions and associated risk factors in HD and PD patients.

METHODS

Forty-four healthy individuals, 62 HD and 50 PD patients were enrolled in the study. Echocardiography was performed before midweek dialysis session for HD patients and on admission for PD patients. Data were expressed as mean ± SD. Spearman's test was used to assess linear associations. Predictors of left intra-atrial EMD time and LA active emptying volume (LAaeV) were assessed by regression analysis.

RESULTS

Left intra-atrial-AEMD times were significantly longer in HD patients compared to PD patients. LAaeV was positively correlated with inter-atrial time, left intra-atrial time, systolic and diastolic BP, calcium and neutrophil-to-lymphocyte ratio (NLR) (r 0.22, p 0.016; r 0.28, p 0.002; r 0.34, p < 0.001; r 0.35, p < 0.001; r 0.37, p < 0.001; r 0.46, p < 0.001, respectively) and negatively correlated with serum uric acid (r -0.31, p 0.013) in ESRD patients. We found positive correlations between left intra-atrial time and LAaeV, LAVmax, LAVp and NLR (r 0.28, p 0.002; r 0.27, p 0.003; r 0.27, p 0.003; r 0.22, p 0.03, respectively) and negative correlations with albumin, uric acid and potassium (r -0.24, p 0.008; r -0.19, p 0.04; r -0.26, p 0.037, respectively). Advanced age, decreased serum albumin and increased NLR were found to be independent predictors of LAaeV; however, only NLR was found to be an independent predictor of AEMD time in this population.

CONCLUSIONS

Increased inflammation might be a risk factor of AEMD and LA mechanical dysfunction in ESRD patients.