Search Results (35)

Background/Objectives: Thrombotic thrombocytopenic purpura (TTP) is a microangiopathic hemolytic anemia exhibiting 90% mortality without prompt treatment. The aim of this study was to investigate the association of therapeutic plasma exchange (TPE)-treated TTP in end-stage renal disease (ESRD) patients with mortality, demographics, and clinical comorbidities. We queried the United States Renal Data System for ESRD patients starting dialysis between 1 January 2005 and 31 December 2018, using International Classification of Diseases (ICD)-9 and ICD-10 codes for thrombotic microangiopathy, with a TPE procedure code entered within 7 days. Methods: Cox proportional hazards models were used to assess mortality, adjusting for demographic and clinical factors. Results: Among 1,155,136 patients, increased age [adjusted odds ratio (OR) = 0.96, 95% confidence interval (CI): 0.94–0.96]; black race (OR = 0.67, CI: 0.51–0.89); and Hispanic ethnicity (OR = 0.43, CI: 0.28–0.66) were associated with a lower risk of TPE-treated TTP diagnosis, whereas female sex (OR = 1.59, CI: 1.25–2.02) and tobacco use (OR = 2.08, CI: 1.58–2.75) had a higher risk. A claim for TPE-treated TTP carried a lower risk of death (adjusted hazard ratio = 0.024, CI: 0.021–0.028). Female sex, black race, Hispanic ethnicity, and hypothyroidism were also associated with decreased all-cause mortality. Conclusions: These findings suggest that ESRD patients with TPE-treated TTP are significantly protected from mortality compared with ESRD patients without this diagnosis. Full article

Background: Despite the survival benefit of ICDs in patients with HFrEF, most recipients do not receive appropriate therapy during follow-up. Existing risk models based on echocardiographic and clinical parameters show limited predictive accuracy for arrhythmic events. This study aimed to assess whether ECG-derived markers outperform conventional measures in predicting appropriate ICD shocks. Methods: This retrospective observational study included 375 patients with HFrEF who underwent ICD implantation for primary prevention at least six months before study enrollment. Twelve-lead surface ECGs were analyzed for a QTc interval, Tp-e/QT ratio, frontal QRS-T angle, and maximum deflection index (MDI). Clinical, echocardiographic, and arrhythmic event data obtained from device interrogations were evaluated. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression were performed to identify independent predictors of appropriate ICD shocks. Results: Patients who experienced appropriate ICD shocks had significantly higher rates of a complete bundle branch block, digoxin use, QRS duration, QTc, Tp-e/QT ratio, frontal QRS-T angle, MDI, and right-ventricular pacing ratio. Conversely, beta-blocker use was significantly lower in this group. In multivariate analysis, independent predictors of appropriate shocks included the patient’s digoxin use (OR = 2.931, p = 0.003), beta-blocker use (OR = 0.275, p = 0.002), frontal QRS-T angle (OR = 1.009, p < 0.001), QTc interval (OR = 1.020, p < 0.001), and Tp-e/QT ratio (OR = 4.882, p = 0.050). The frontal QRS-T angle had a cutoff value of 105.5° for predicting appropriate ICD shocks (sensitivity: 73.6%, specificity: 85.2%, AUC = 0.758, p < 0.001). Conclusions: Electrocardiographic markers, particularly the frontal QRS-T angle, QTc interval, and Tp-e/QT ratio, demonstrated superior predictive power for appropriate ICD shocks compared to conventional echocardiographic and clinical measures. These easily obtainable, non-invasive ECG parameters may improve current risk stratification models and support more individualized ICD implantation strategies. Full article

Background/Objectives: Sudden unexpected death in epilepsy (SUDEP) is a major cause of mortality in pediatric epilepsy. Cardiac arrhythmias, possibly reflected by electrocardiographic (ECG) abnormalities, are thought to contribute significantly to SUDEP risk. This study aimed to evaluate ECG indices associated with an increased risk of both atrial and ventricular arrhythmias and sudden cardiac death in pediatric patients with generalized and focal seizures, excluding those with underlying channelopathies. Materials and Methods: Pediatric patients aged 0–18 years with generalized or focal epilepsy followed at our center between October 2024 and April 2025 were enrolled. Comprehensive cardiac evaluations, including echocardiography and 12-lead ECG, were conducted. Patients with channelopathies, structural heart defects, or significant congenital heart disease were excluded. ECG parameters—QT dispersion (QT Disp), corrected QT interval (QTc), QTc dispersion (QTc Disp), P-wave dispersion (P Disp), and T peak-T end interval (Tp-e)—were analyzed across epilepsy subgroups and compared to healthy controls. Effects of antiepileptic drug (AED) use and gender were also assessed. Results: A total of 151 participants were included (generalized: n = 51; focal: n = 50; controls: n = 50). QTc and Tp-e intervals were prolonged in both epilepsy groups compared to controls (p = 0.001 and p = 0.036, respectively), however, they fell within the conventional parameters. AED use was associated with further prolongation of QTc (p = 0.035) and Tp-e (p = 0.037), these metrics were similarly found to be within the established normative boundaries. Phenobarbital and lamotrigine users showed the longest QTc, albeit not statistically significant. Males with generalized seizures had longer maximum P-wave duration (P Max) than females (p = 0.009). A moderate correlation was found between Tp-e and QTc (r = 0.557, p = 0.001). Conclusions: Although there are findings in our study that may suggest a relationship between SUDEP and arrhythmia according to electrocardiographic markers associated with arrhythmia risk, larger and prospective studies with long-term follow-up are needed in the future. Full article

Background and Objectives: Major depressive disorder (MDD) is a prevalent psychiatric illness increasingly recognized as a systemic condition with implications for cardiovascular diseases. Growing evidence indicates that individuals with MDD have an elevated risk of cardiovascular mortality, underscoring the need for reliable, non-invasive biomarkers to assess cardiac risk. While underlying mechanisms remain unclear, electrocardiogram (ECG)-based markers offer a promising, non-invasive means of evaluation. Among these, the electrical risk score (ERS), a composite derived from specific ECG parameters, has emerged as a predictor of adverse cardiac outcomes. This study aimed to investigate the association between ERS and MDD, and whether ERS correlates with depression severity and illness duration. Materials and Methods: In this retrospective cross-sectional study, 12-lead ECGs were evaluated to calculate the ERS based on six ECG parameters: heart rate, corrected QT interval, Tp-e interval, frontal QRS-T angle, QRS transition zone, and presence of left ventricular hypertrophy according to Sokolow–Lyon criteria. The Hamilton Depression Rating Scale (HAM-D) was utilized. Results: The study included 102 patients with MDD and 62 healthy controls. No significant differences were observed in baseline or laboratory parameters between the groups. However, heart rate, Tp-e interval, frontal QRS-T angle, and ERS were significantly higher in the depression group. ROC analysis identified ERS as the strongest predictor of depression. ERS was significantly higher in patients with severe depression compared to those with mild symptoms and showed a positive correlation with both disease duration and HAM-D score. Conclusions: Here, we show that the ECG-derived ERS is significantly elevated in patients with MDD and is associated with increased cardiac risk. ERS outperformed conventional ECG parameters in identifying individuals with depression and demonstrated positive associations with both illness duration and symptom severity. These findings suggest that ERS may serve as a practical, non-invasive biomarker for assessing cardiovascular vulnerability in this population. Full article

Background/Objectives: Immune checkpoint inhibitor (ICI)-associated cardiovascular adverse events are relatively uncommon; they can be life-threatening, particularly when involving malignant ventricular arrhythmias. Electrocardiographic markers such as P-wave dispersion (PWD), QT dispersion (QTd), T-peak to T-end (Tp-e) interval, and Tp-e/QT and Tp-e/QTc ratios have been linked to an elevated risk of both atrial and ventricular arrhythmias and sudden cardiac death across various cardiac conditions. Monitoring these parameters may aid in identifying the risk of arrhythmogenic events in cancer patients undergoing ICI therapy. Methods: This retrospective cohort study analyzed 42 patients with cancer who received ICI therapy and had serial 12-lead electrocardiograms (ECGs) performed at baseline and at three-month intervals during the first year of treatment, from May 2022 to November 2023. ECG parameters including PWD, QTd, Tp-e interval, and Tp-e/QT and Tp-e/QTc ratios were measured and compared between baseline and follow-up time points. Results: The median follow-up duration was 5.3 months (range: 0.5–18.9 months). No statistically significant differences were observed in any of the ECG parameters between baseline and subsequent measurements (p > 0.05). One patient developed atrial fibrillation during the third month of treatment. Additionally, one patient exhibited a left anterior fascicular block, and another experienced frequent ventricular extrasystoles. No malignant ventricular arrhythmias were reported throughout the study period. Conclusions: This study found no significant changes in electrocardiographic markers associated with arrhythmia risk during ICI treatment. Larger, multicenter, prospective studies with extended follow-up are warranted to further elucidate the cardiovascular safety profile of ICIs. Full article

Background and Objectives: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease associated with significant morbidity, including cardiovascular complications. This study investigates the relationship between NAFLD and electrocardiographic parameters indicative of ventricular arrhythmia risk. Materials and Methods: We conducted a cross-sectional study enrolling 136 patients with NAFLD and 136 healthy controls. Electrocardiographic parameters—Tp-e interval, QT and corrected QT (QTc) intervals, and Tp-e/QTc ratio—were measured and compared between groups. Results: Patients with NAFLD exhibited significantly higher Tp-e, QTc, Tp-e/QT ratio, and Tp-e/QTc ratio (p < 0.001, for all) than controls. Subgroup analysis showed progressive increases in Tp-e and Tp-e/QT ratio correlating with NAFLD severity (p < 0.001 and p = 0.001, respectively, for grade 1 vs. grade 2; p < 0.001 and p = 0.001, respectively, for grade 1 vs. grade 3). ROC analysis indicated that the Tp-e interval was a strong predictor for identifying grade 2 or more NAFLD (AUC 0.887, p < 0.001). Conclusions: Our findings highlight the association of NAFLD with prolonged electrocardiographic intervals that may predispose patients to ventricular arrhythmias. These parameters can serve as valuable markers for cardiac risk stratification in patients with NAFLD, suggesting the need for vigilant cardiac follow-up in this population. Full article

Background: Congenital long QT syndrome (LQTS) is a rare cardiac disorder caused by repolarization abnormalities in the myocardium that predisposes to ventricular arrhythmias and sudden cardiac death. Potassium channel-mediated LQT1 and LQT2 are the most common types of channelopathy. Recently, LQTS has been acknowledged as an electromechanical disease. Methods: A total of 87 genotyped LQT1/LQT2 patients underwent cardiac evaluation. A comparison between LQT1 and LQT2 electrical and mechanical parameters was performed. Results: LQT2 patients had worse electrical parameters at rest: a longer QTc interval (p = 0.007), a longer T_pe in lead V2 (p = 0.028) and in lead V5 (p < 0.001), and a higher T_pe/QT ratio in lead V2 (p = 0.011) and in lead V5 (p = 0.005). T_pe and T_pe/QT remained significantly higher in the LQT2 group after brisk standing. T_pe was longer in LQT2 patients compared with LQT1 patients during peak exercise (p = 0.007) and almost all recovery periods in lead V2 during EST. The mid-cavity myocardium mean radial contraction duration (CD) was longer in LQT2 patients (p = 0.02). LQT2 patients had a longer mean radial CD in mid-septal (p = 0.015), mid-inferior (p = 0.034), and mid-posterior (p = 0.044) segments. Conclusions: Potassium channel-mediated LQTS has different effects on cardiac electromechanics with a more pronounced impact on LQT2 patients. T_pe was more prominent in the LQT2 cohort, not only at rest and brisk standing but also during EST exercise and at recovery phases. The altered mean radial CD in the mid-cavity myocardium was also specific for LQT2 patients. Full article

Objective: This study evaluates the short-term cardiovascular effects of guanfacine treatment in children and adolescents with attention deficit/hyperactivity disorder (ADHD). The treatment’s impact on novel electrocardiographic parameters was also investigated. Methods: In a retrospective study conducted between January 2023 and June 2024, 37 patients aged 6–18 years with ADHD underwent baseline and follow-up cardiac evaluations including electrocardiography (ECG) and blood pressure measurements. Novel ECG markers (QRS-T angle, QT dispersion, QTc dispersion, Tp-e interval, Tp-e dispersion, Tp-e/QT ratio, and Tp-e/QTc ratio) were analyzed alongside standard parameters such as heart rate, QT, and corrected QT (QTc) intervals. Guanfacine was initiated at 1 mg and titrated weekly until an optimal clinical response was achieved. Results: Guanfacine treatment led to a significant reduction in heart rate (−12.3 bpm; p < 0.001) and P wave axis (−12.3°; p = 0.038) and an increase in QT interval (+16.8 ms; p = 0.014). However, no significant changes were observed in blood pressure, QTc duration, or the novel ECG parameters. Importantly, the absence of any changes in these advanced markers supports the cardiovascular safety of guanfacine. Two patients experienced side effects (bradycardia and hypotension), leading to treatment discontinuation. ANCOVA analysis indicated that the duration between ECG evaluations significantly influenced the QT interval changes, emphasizing the importance of timing when monitoring cardiovascular effects. Conclusions: Guanfacine demonstrated minor, statistically significant effects on the selected cardiac parameters without clinically meaningful changes to or adverse impacts on the novel ECG markers investigated. As extended-release guanfacine has only been available in Türkiye for the management of ADHD for approximately two years, studies evaluating its clinical efficacy and side effects are critical for clinicians working in this field. Full article

Interval prediction is to predict the range of power prediction intervals, which can guide electricity production and usage better. To improve further improve the performance of the prediction interval, this paper aims to investigate he wind power interval prediction method based on the lower and upper bound evaluation (LUBE). Firstly, an improved loss function is proposed, which transforms multi-objective optimization problems into single-objective optimization with guidance of mathematical derivation. Afterward, the interval prediction results can be further improved through a combination of graph convolutional network (GCN) and gate recurrent unit (GRU). Then, the tree-structured Parzen estimator (TPE) optimization algorithm optimizes the GCN cell to find the optimal parameter configuration and maximize the performance of the model. Finally, in the experimental part, the proposed GCN-GRU with improved loss function is compared with some current mainstream neural networks. The results show that for any type of network, the improved loss function can obtain prediction intervals with better performance. Especially for the prediction interval based on GCN-GRU, the prediction interval normalized average width (PINAW) and prediction interval relative deviation (PIRD) can reach 6.75% and 46.99%, respectively, while ensuring the given prediction interval nominal confidence (PINC). Full article

In systemic sclerosis (SSc), fibrosis of the myocardium along with ongoing autoimmune inflammation can alter the electric function of the cardiac myocytes, which may increase the risk for ventricular arrhythmias and sudden cardiac death. We analyzed the electrocardiographic (ECG) variables describing ventricular repolarization such as QT interval, QT dispersion (QTd), T wave peak-to-end interval (Tpe), and arrhythmogeneity index (AIX) of 26 patients with SSc and 36 healthy controls. Furthermore, echocardiographic and laboratory parameters were examined, with a focus on inflammatory proteins like C-reactive ptotein (CRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), and progranulin (PGRN). The CRP, sICAM-1, and sVCAM-1 levels were positively correlated with the length of the QT interval. Although the serum PGRN levels were not increased in the SSc group compared to the controls, in SSc patients, the PGRN levels were positively correlated with the QT interval and the AIX. According to our results, we conclude that there may be a potential association between autoimmune inflammation and the risk for ventricular arrhythmias in patients with SSc. We emphasize that the measurement of laboratory parameters of inflammatory activity including CRP, PGRN, sVCAM-1, and sICAM-1 could be helpful in the prediction of sudden cardiac death in patients with SSc. Full article

Sharding technology, which divides a network into multiple disjoint groups so that transactions can be processed in parallel, is applied to blockchain systems as a promising solution to improve Transactions Per Second (TPS). This paper considers the Optimal Blockchain Sharding (OBCS) problem as a Markov Decision Process (MDP) where the decision variables are the number of shards, block size and block interval. Previous works solved the OBCS problem via Deep Reinforcement Learning (DRL)-based methods, where the action space must be discretized to increase processability. However, the discretization degrades the quality of the solution since the optimal solution usually lies between discrete values. In this paper, we treat the block size and block interval as continuous decision variables and provide dynamic sharding strategies based on them. The Branching Dueling Q-Network Blockchain Sharding (BDQBS) algorithm is designed for discrete action spaces. Compared with traditional DRL algorithms, the BDQBS overcomes the drawbacks of high action space dimensions and difficulty in training neural networks. And it improves the performance of the blockchain system by 1.25 times. We also propose a sharding control algorithm based on the Parameterized Deep Q-Networks (P-DQN) algorithm, i.e., the Parameterized Deep Q-Networks Blockchain Sharding (P-DQNBS) algorithm, to efficiently handle the discrete–continuous hybrid action space without the scalability issues. Also, the method can effectively improve the TPS by up to $28\%$. Full article

Tactile acuity is typically measured by a two-point discrimination test (TPD) and a two-point estimation task (TPE). In the back area, they are only conducted in the lumbar and cervical regions of the spine. Considering that such measurements have not been conducted in the sacral regions, the purpose of this study was to assess the inter- and intra-examiner reliability of the TPD and TPE at the level of the S3 segment. The study included 30 pain-free subjects aged 20–30 years. Tests were performed with a pair of stainless hardened digital calipers. The TPD was measured in two locations: 5 and 15 cm from the midline; for TPE both, points were located inside the measured area. Session 1 involved assessments by two examiners in 10-min intervals. Session 2 was measured by one examiner, at analogous intervals between tests. The TPD inter-rater reliability was excellent for mean measurements (ICC_3.2: 0.76–0.8; ICC_3.3: 0.8–0.92); the intra-rater reliability was excellent for mean measurements (ICC_2.2: 0.79–0.85; ICC_2.3: 0.82–0.86). The TPE inter-rater reliability was good to excellent for mean measurements (ICC_3.2: 0.65–0.92; ICC_3.3: 0.73–0.94); the intra-rater reliability for all studies (ICC_2.1, ICC_2.2, ICC_2.3) was excellent (0.85–0.89). Two measurements are sufficient to achieve good reliability (ICC ≥ 0.75), regardless of the assessed body side. Full article

Background: Cardiac complications due to anthracycline treatment may become evident several years after chemotherapy and are recognized as a serious cause of morbidity and mortality in cancer patients or childhood cancer survivors. Objectives: We analyzed ventricular repolarization parameters in electrocardiography for pediatric acute lymphoblastic leukemia patients during chemotherapy and in long-term follow-up. To establish the reference values of ventricular repolarization parameters in children, we retrospectively summarized the Tpe interval, QT interval, QTc interval, and Tpe/QT ratio in healthy Japanese children. Methods: Electrocardiography data recorded from students in 1st and 7th grades were randomly selected from a database maintained by the school-based screening system in the Oita city cohort, Japan. Subsequently, chronological data of the Tpe/QT ratio in 17 pediatric patients with acute lymphoblastic leukemia were analyzed over time. Results: The mean ± standard deviation of the Tpe interval in 1st and 7th graders was 70 ± 7 and 78 ± 17 ms, respectively, while the mean ± standard deviation of the Tpe/QT ratio was 0.21 ± 0.02 and 0.22 ± 0.02 ms, respectively. During the intensive phase of treatment, the Tpe/QT ratios of 3 high-risk patients among the 17 patients with acute lymphoblastic leukemia exceeded the upper limit. Conclusion: The Tpe/QT ratio has a potential clinical application in predicting the risk of long-term ventricular arrhythmia of cancer patients or childhood cancer survivors from childhood to adulthood. Full article

The most common cause of death in patients with Duchenne muscular dystrophy (DMD) is cardiomyopathy. Our aim was to investigate the relationship between the Tpeak–Tend (Tp-e) interval and the premature ventricular contraction (PVC) burden and therefore early arrhythmic risk and cardiac involvement in DMD patients. Twenty-five patients with DMD followed by pediatric cardiology were included in the study. Those with a frequency of <1% PVC in the 24 h Holter were assigned to Group 1 (n = 15), and those with >1% were assigned to Group 2 (n = 10). Comparisons were made with healthy controls (n = 27). Left ventricular ejection fraction (LVEF) was lowest in Group 2 and highest in the control group (p < 0.001). LV end-diastolic diameter was greater in Group 2 than in Group 1 and the control group (p = 0.005). Pro-BNP and troponin levels were higher in Group 1 and Group 2 than in the control group (p = 0.001 and p < 0.001, respectively). Tp-e interval was longer in Group 2 compared to Group 1 and the control group (p < 0.001). The LVEF (OR 0.879, 95% CI 0.812–0.953; p = 0.002) and Tp-e interval (OR 1.181, 95% CI 1.047–1.332; p = 0.007) were independent predictors of PVC/24 h frequency of >1%. A Tp-e interval > 71.65 ms predicts PVC > 1%, with a sensitivity of 80% and a specificity of 90% (AUC = 0.842, 95% CI (0.663–1.000), p = 0.001). Determination of Tp-e prolongation from ECG data may help in the determination of cardiac involvement and early diagnosis of arrhythmic risk in DMD. Full article

Background and Objectives: Smokeless tobacco (ST) use has recently become an alternative to cigarettes, and it has been concluded that ST is at least as harmful as cigarettes. ST use is thought to play a role in the pathogenesis of arrhythmia by affecting ventricular repolarization. In this study, we aimed to examine the relationships of Maras powder (MP), one of the ST varieties, with epicardial fat thickness and new ventricular repolarization parameters, which have not previously been described. Materials and Methods: A total of 289 male individuals were included in this study between April 2022 and December 2022. Three groups, 97 MP users, 97 smokers, and 95 healthy (non-tobacco), were compared according to electrocardiographic and echocardiographic data. Electrocardiograms (ECG) were evaluated with a magnifying glass by two expert cardiologists at a speed of 50 m/s. Epicardial fat thickness (EFT) was measured by echocardiography in the parasternal short- and long-axis images. A model was created with variables that could affect epicardial fat thickness. Results: There were no differences between the groups regarding body mass index (p = 0.672) and age (p = 0.306). The low-density lipoprotein value was higher in the MP user group (p = 0.003). The QT interval was similar between groups. Tp-e (p = 0.022), cTp-e (p = 0.013), Tp-e/QT (p =0.005), and Tp-e/cQT (p = 0.012) were higher in the MP user group. While the Tp-e/QT ratio did not affect EFT, MP predicted the epicardial fat thickness (p < 0.001, B = 0.522, 95%CI 0.272–0.773). Conclusions: Maras powder may play a role in ventricular arrhythmia by affecting EFT and causing an increase in the Tp-e interval. Full article