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Introduction: The relationship between blood N-3 polyunsaturated fatty acid (PUFA) levels and cardiovascular health is known, but direct evidence that N-3 PUFA levels influence electrocardiographic (ECG) parameters is non-existent. In the study described herein, we investigated the relationship between anthropometric biomarkers and capillary blood PUFAs with ECG outputs in a sample population of healthy pre-menopausal women. Method: Twenty-three consenting females were recruited, with the study power analysis sufficiently demonstrated. Food intake, anthropometric and cardiovascular parameters were obtained. Capillary blood was collected for fatty acid chromatographic analysis. Results: Body mass index, haematocrit, heart rate (HR), mean arterial pressure (MAP) and ECG readings all fell within healthy ranges. Principal component analysis-mediated correlations were carried out controlling for combined Components 1 (age, body fat % and waist-to-hip ratio) and 2 (height, HR and MAP) as control variables. Docosahexaenoic acid (DHA) unequivocally decreased the QRS area under the curve (AUC-QRS) regardless of the impact of control variables, with each unit increase in DHA corresponding to a 2.3-unit decrease in AUC-QRS. Mediation analysis revealed a significant overall effect of DHA on AUC-QRS, with the impact of DHA on R wave amplitude accounting for 77% of the total observed effect. Discussion: Our new findings revealed an inverse relationship between AUC-QRS with capillary blood DHA, suggesting that the association between ventricular mass and its QRS depolarising voltage is mediated by DHA. Our findings bridge a knowledge gap on the relationship between ventricular mass and ventricular efficiency. Further research will confirm whether the relationship identified in our study also exists in diseased patients. [ABSTRACT FROM AUTHOR]

Research on the automated extraction of essential data from an electrocardiography (ECG) recording has been a significant topic for a long time. The main focus of digital processing processes is to measure fiducial points that determine the beginning and end of the P, QRS, and T waves based on their waveform properties. The presence of unavoidable noise during ECG data collection and inherent physiological differences among individuals make it challenging to accurately identify these reference points, resulting in suboptimal performance. This is done through several primary stages that rely on the idea of preliminary processing of the ECG electrical signal through a set of steps (preparing raw data and converting them into files that are read and then processed by removing empty data and unifying the width of the signal at a length of 250 in order to remove noise accurately, and then performing the process of identifying the QRS in the first place and PT implicitly, and then the task stage is determining the required peak and making a cut based on it. The U-Net pre-trained model is used for deep learning. It takes an ECG signal with a customizable sampling rate as input and generates a list of the beginning and ending points of P and T waves, as well as QRS complexes, as output. The distinguishing features of our segmentation method are its high speed, minimal parameter requirements, and strong generalization capabilities, which are used to create data that can be used in diagnosing diseases or biometric systems. [ABSTRACT FROM AUTHOR]

Women might benefit more than men from cardiac resynchronization therapy (CRT) and do so at shorter QRS durations. This meta-analysis was performed to determine whether sex-based differences in CRT effects are better accounted for by height, body surface area (BSA), or left ventricular end-diastolic dimension (LVEDD). We analyzed patient-level data from CRT trials (MIRACLE, MIRACLE ICD, MIRACLE ICD II, REVERSE, RAFT, COMPANION, and MADIT-CRT) using bayesian hierarchical Weibull regression models. Relationships between QRS duration and CRT effects were examined overall and in sex-stratified cohorts; additional analyses indexed QRS duration by height, BSA, or LVEDD. End points were heart failure hospitalization (HFH) or death and all-cause mortality. Compared with men (n = 5628), women (n = 1439) were shorter (1.62 [interquartile range, 1.57–1.65] m vs 1.75 [1.70–1.80] m; P <.001), with smaller BSAs (1.76 [1.62–1.90] m2 vs 2.02 [1.89–2.16] m2; P <.001). In adjusted sex-stratified analyses, the reduction in HFH or death was greater for women (hazard ratio, 0.54; credible interval, 0.42–0.70) than for men (hazard ratio, 0.77; credible interval, 0.66–0.89; P interaction =.009); results were similar for all-cause mortality even after adjustment for height, BSA, and LVEDD. Sex-specific differences were observed only in nonischemic cardiomyopathy. The effect of CRT on HFH or death was observed at a shorter QRS duration for women (126 ms) than for men (145 ms). Indexing QRS duration by height, BSA, or LVEDD attenuated sex-specific QRS duration thresholds for the effects of CRT on HFH or death but not on mortality. Although body size partially explains sex-specific QRS duration thresholds for CRT benefit, it is not associated with the magnitude of CRT benefit. Indexing QRS duration for body size might improve selection of patients for CRT, particularly with a "borderline" QRS duration. [Display omitted] [ABSTRACT FROM AUTHOR]

Introduction: The efficacy of de novo cardiac resynchronisation therapy (CRT) in patients with heart failure (HF), left ventricular systolic dysfunction (LVSD), and a broad QRS morphology is well established. However, the optimal stage for upgrading patients with existing pacemakers (PPMs) or implantable cardioverter-defibrillators (ICDs) and HF with high-burden right ventricular (RV) pacing remains uncertain. Thus, this multicentre retrospective analysis compared patients with pre-existing PPMs or ICDs who underwent CRT upgrades to investigate the appropriate stage for CRT implantation in these patients and to assess the validity of treating both PPM and ICD recipients under the same recommendation level in the current guidelines. Materials and Methods: A total of 151 participants underwent analysis in this study, comprising 93 upgrades to cardiac resynchronisation therapy with pacemaker (CRT-P) and 58 upgrades to cardiac resynchronisation therapy with defibrillator (CRT-D) across three centres in the UK. The aim of the study was to investigate the safety and efficacy of upgrading to CRT from an existing conventional pacemaker or an ICD in the context of high-burden RV pacing. The analysis was conducted separately for each group, assessing changes in echocardiographic parameters, functional New York Heart Association (NYHA) class, and procedure-related complications. Results: The PPM group had a higher percentage RVP burden compared to the ICD group. Post-upgrade, NYHA functional class and EF and LV volumes improved in both groups; however, the response to an upgrade from a pacemaker was greater compared to an upgrade from an ICD. Post-procedural complication risks were similar across the two subgroups but significantly higher compared to de novo implantation. Conclusions: Within the CRT-P subgroup, participants exhibited better responses than their CRT-D counterparts, evident both in echocardiographic improvements and clinical outcomes. Furthermore, patients with non-ischemic cardiomyopathy (NICM) were better responders than those with ischaemic cardiomyopathy. These findings suggest that international guidelines should consider approaching each subgroup separately in the future. [ABSTRACT FROM AUTHOR]

Introduction: Right ventricular (RV) pacing sometimes causes left ventricular (LV) systolic dysfunction, also known as pacing‐induced cardiomyopathy (PICM). However, the association between specifically paced QRS morphology and PICM development has not been elucidated. This study aimed to investigate the association between paced QRS mimicking a complete left bundle branch block (CLBBB) and PICM development. Methods: We retrospectively screened 2009 patients who underwent pacemaker implantation from 2010 to 2020 in seven institutions. Patients who received pacemakers for an advanced atrioventricular block or bradycardia with atrial fibrillation, baseline LV ejection fraction (LVEF) ≥ 50%, and echocardiogram recorded at least 6 months postimplantation were included. The paced QRS recorded immediately after implantation was analyzed. A CLBBB‐like paced QRS was defined as meeting the CLBBB criteria of the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society in 2009. PICM was defined as a ≥10% LVEF decrease, resulting in an LVEF of <50%. Results: Among the 270 patients analyzed, PICM was observed in 38. Baseline LVEF was lower in patients with PICM, and CLBBB‐like paced QRS was frequently observed in PICM. Multivariate analysis revealed that low baseline LVEF (odds ratio [OR]: 0.93 per 1% increase, 95% confidence interval [CI]: 0.89–0.98, p = 0.006) and CLBBB‐like paced QRS (OR: 2.69, 95% CI: 1.25–5.76, p = 0.011) were significantly associated with PICM development. Conclusion: CLBBB‐like paced QRS may be a novel risk factor for PICM. RV pacing, which causes CLBBB‐like QRS morphology, may need to be avoided, and patients with CLBBB‐like paced QRS should be followed‐up carefully. [ABSTRACT FROM AUTHOR]

Background: Height, left ventricular (LV) size, and sex were proposed as additional criteria for patient selection for cardiac resynchronization therapy (CRT) but their connections with the QRS complex in left bundle branch block (LBBB) are little investigated. We evaluated these. Methods: Among patients with "true" LBBB, QRS duration (QRSd) and amplitude, and LV hypertrophy indices, were correlated with patient's height and LV mass, and compared between sexes. Results: In this study cohort (n = 220; 60 ± 12 years; left ventricular ejection fraction [LVEF] 21 ± 7%; mostly New York Heart Association II–III, QRSd 165 ± 19 ms; 57% female; 70% responders [LVEF increased ≥5%]), LV mass was increased in all patients. QRS amplitude did not correlate with LV mass or height in any individual lead or with Sokolow‐Lyon or Cornell‐Lyon indices. QRSd did not correlate with height. In contrast, QRSd correlated strongly with LV mass (r =.51). CRT response rate was greater in women versus men (84% vs. 58%, p <.001) despite shorter QRSd [7% shorter (p <.0001)]. QRSd normalized for height resulted in a 2.7% and for LV mass 24% greater index in women. Conclusion: True LBBB criteria do not exclude HF patients with increased LV mass. QRS amplitudes do not correlate with height or LV mass. Height does not affect QRSd. However, QRSd correlates with LV size. QRSd normalized for LV mass results in 24% greater value in women in the direction of sex‐specific responses. LV mass may be a significant nonelectrical modifier of QRSd for CRT. [ABSTRACT FROM AUTHOR]

Background: Sudden cardiac death (SCD) in young adults has a rare incidence but it is tragic. It affects five per 100,000 yearly according to some studies. One of the main causes of SCD especially in young adults is non-structural heart diseases that include long QT syndrome, short QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, idiopathic ventricular fibrillation (IVF), atrioventricular node block, and recently early repolarization. In Egypt there is no sufficient data about prevalence of these diseases or normal ECG parameters. The aim of this work is to assess the mean and standard deviation of electrocardiography (ECG) parameters in healthy Zagazig University students which will help in addition to old studies and coming studies to better management of sudden cardiac death especially in young adults. Methods: In this study we collected a random sample of healthy students from Zagazig University Student Hospital (during general examination during the application for the university) and student accommodation in August and September 2017.Our sample size was 800 students, 474 were females and 326 were males, the mean age was 18.42 ± 1.1. Results: Athletes has a slower heart rate, wider QRS, and longer QT interval than non-athletes. Females have longer QT and narrower QRS than males. Conclusion: there is a significant difference between athlete and non-athlete and also there is a significant difference between male and female in the mean and standard deviation of QT interval, QRS duration, and heart rate. [ABSTRACT FROM AUTHOR]

Cardiac resynchronization therapy (CRT) for congenital heart disease has shown promising suucess as an adjunct to medical therapy for heart failure. While cardiac conduction defects and need for ventricular pacing are common in congential heart disease, CRT indications, techniques and long term outcomes have not been well establaished. This is a review of the techniques nad short term outcomes of CRT for the following complex congenital heart disease conditions: single ventricle physiology, systemic right ventricle, and the subpulmonic right ventricle. [ABSTRACT FROM AUTHOR]

Background: Sickle cell disease, a common genetic disorder in African Americans, manifests an increased risk of sudden death, the basis of which is incompletely understood. Prolongation of heart rate–corrected QT (QTc) interval on the electrocardiogram, a standard clinical measure of cardiac repolarization, may contribute to sudden death by predisposing to torsades de pointes ventricular tachycardia. Methods: We established a cohort study of 293 adult and 121 pediatric sickle cell disease patients drawn from the same geographic region as the Jackson Heart Study (JHS) cohort, in which significant correlates of QT duration have been characterized and quantitatively modeled. Herein, we establish clinical and laboratory correlates of QTc duration in our cohort using stepwise multivariate linear regression analysis. We then compared our adult sickle cell disease data to effect-size predictions from the published JHS statistical model of QT interval duration. Results: In adult sickle cell disease, gender, diuretic use, QRS duration, serum ALT levels, anion gap, and diastolic blood pressure show positive correlation; hemoglobin levels show inverse correlation; in pediatric sickle cell disease, age, hemoglobin levels, and serum bicarbonate and creatinine levels show inverse correlation. The mean QTc in our adult sickle cell disease cohort is 7.8 milliseconds longer than in the JHS cohort, even though the JHS statistical model predicts that the mean QTc in our cohort should be >11 milliseconds shorter than in the much older JHS cohort, a differential of >18 milliseconds. Conclusion: Sickle cell disease patients have substantial QTc prolongation relative to their age, driven by factors, some overlapping, in adult and pediatric sickle cell disease, and distinct from those that have been defined in the general African American community.

This scientific paper presents a novel approach of real-time signal analysis in electrocardiogram (ECG) monitoring systems, focusing on the integration of device design, algorithm implementation for accurate measurement and interpretation of heart activity. The proposed system leverages a low-cost framework, employing a microcontroller and Arduino programming language for raw ECG data acquisition, while utilizing the AD8232 sensor and ESP8266 Node MCU for continuous patient monitoring. The acquired data is processed, stored, and analyzed using the Pan-Tompkins algorithm, which effectively filters and analyzes heart signals, including noise reduction and QRS complex detection. Two case studies involving a healthy individual and a patient with Myocarditis were conducted to demonstrate the effectiveness of the system. The integration of device design and algorithm development in ECG analysis is emphasized, highlighting the affordability, wearability, and potential for continuous monitoring and early detection of heart conditions. By successfully mitigating noise-related challenges, the implementation of the Pan algorithm enables accurate signal analysis. This interdisciplinary research contributes to the advancement of ECG interpretation and underscores the significance of clinical fusion between designed systems and applied algorithms on real cases. The performance of two Pan-Tompkins based QRS complex detection algorithms was systematically analyzed, offering valuable insights for their reasonable utilization. [ABSTRACT FROM AUTHOR]

Bupropion toxicity can cause cardiogenic shock, ventricular dysrhythmias, and death. Clinical and electrocardiographic factors associated with adverse cardiovascular events in bupropion toxicity have not been well-studied. This study aimed to identify factors associated with adverse cardiovascular events in adult patients with isolated bupropion exposures. This retrospective cohort study queried the National Poison Data System from 2019 through 2020. We included patients 20 years or older with acute or acute-on-chronic single-agent bupropion exposures evaluated in a healthcare facility. Exclusion criteria were confirmed non-exposure, withdrawal as a reason for exposure, lack of follow-up, documentation that exposure was probably not responsible for the effects, and missing data. The primary outcome was adverse cardiovascular events, defined as the presence of any of the following: vasopressor use, ventricular dysrhythmia, myocardial injury, or cardiac arrest. Independent variables were age, the intentionality of exposure, seizures, tachycardia, QRS widening, and QTc prolongation. Multivariable logistic regression was performed to test for independent associations between independent variables and adverse cardiovascular events. Of 4,640 patients included in the final analysis (56.7% female, 56.5% suspected suicidal intent), 68 (1.47%) experienced an adverse cardiovascular event. Age (odds ratio 1.03; 95% confidence intervals 1.02–1.05), single seizure (odds ratio 9.18; 95% confidence intervals 4.24–19.9) and complicated seizures (odds ratio 38.9; 95% confidence intervals 19.3–78.1), QRS widening (odds ratio 3.01; 95% confidence intervals 1.62–5.59), and QTc prolongation (odds ratio 1.76; 95% confidence intervals 1.00–3.10) were independently associated with adverse cardiovascular events. No patients with unintentional exposure experienced adverse cardiovascular events, prohibiting intentionality from inclusion in the regression model. In the post hoc subgroup analysis of intentional exposures, age, single and complicated seizures, and QRS widening remained independently associated with adverse cardiovascular events. Increasing age, seizures, QRS widening, and QTc prolongation were associated with adverse cardiovascular events in bupropion exposures. Adverse cardiovascular events did not occur in unintentional exposures. Further research is needed to develop screening tools and treatments for bupropion cardiotoxicity. [ABSTRACT FROM AUTHOR]

Bupropion cardiotoxicity widens QRS complexes by inhibiting cardiac gap junctions. Sodium bicarbonate is the standard treatment for QRS widening from sodium channel blockade, but its effect on QRS widening in bupropion cardiotoxicity is not well-studied. This is a retrospective cohort study of bupropion overdoses from 10 hospitals between January 2010 and June 2022. Patients with documented administration of sodium bicarbonate and QRS duration > 100 milliseconds on pre-bicarbonate electrocardiogram were included. Patients with no electrocardiogram within four hours of treatment or with baseline pre-overdose wide QRS and < 10 milliseconds widening from baseline were excluded. The primary outcome was a change in QRS duration between the pre-bicarbonate electrocardiogram and the first electrocardiogram after initial bicarbonate administration. Secondary outcomes included prevalence of post-bicarbonate QRS < 100 milliseconds, change in electrocardiogram intervals after total bicarbonate administration, and change in metabolic parameters and hemodynamics. Wilcoxon signed-rank testing was performed on the primary outcome. Linear regression modeling was performed to test for an association between change in QRS and bicarbonate dosing. Thirteen patients were included for final analysis. The median age was 32 years, and 54% were male. Six patients developed seizures; one developed ventricular tachycardia, and four received vasopressors. The median QRS and QTc pre-bicarbonate were 116 and 495 milliseconds, respectively. The median change in QRS duration was −2.0 milliseconds, which was not statistically significant (P = 0.42). The median bicarbonate dose administered before the first post-bicarbonate electrocardiogram was 100 milliequivalents. We did not identify an association between QRS change and bicarbonate dosing (P = 0.9, R-squared = 0.001). No patient had a QRS duration < 100 milliseconds after the initial bicarbonate dose. There was minimal change in QTc, electrolytes, heart rate, or blood pressure; alkalemia post-bicarbonate was achieved in eight patients. Sodium bicarbonate did not significantly decrease QRS duration in this small retrospective cohort of bupropion overdoses. [ABSTRACT FROM AUTHOR]

Acute ST-segment elevation myocardial infarction (STEMI) still affects people's health due to its high prevalence and high mortality rate. Electrocardiogram (ECG), as a commonly used non-interventional type of examination, has unique pathophysiological and clinical significance. Here we list the significance of QRS wave for early diagnosis and prognostic assessment in STEMI patients, such as QRS duration, QRS-T angle, QRS distortion, fragmented QRS, QRS scores, R wave peak time, triangular QRS-ST-T waveform, QRS low voltage, etc. Some of these metrics are old, such as the QRS score, QRS duration, for which we list the results of recent studies. Some are newer metrics, such as the fragmented QRS, QRS distortion, for which we summarize the results to date. This article aims to highlight its role in diagnosis and prognostic evaluation, guide clinical practice, and provide new ideas for future scientific research. [ABSTRACT FROM AUTHOR]

The Food and Drug Administration (FDA) warned about lamotrigine's arrhythmogenicity based on in vitro data. This systematic review investigates lamotrigine's effect on cardiac conduction and risk of sudden cardiac death (SCD) in individuals with and without cardiovascular disease. We searched Web of Science and PubMed from inception through August 2021. We included studies measuring electrocardiogram (ECG) changes, laboratory abnormalities, or SCD among patients taking lamotrigine. Studies examining sudden unexpected death in epilepsy were excluded for scope. Two reviewers assessed articles and extracted data. We used the Effective Public Healthcare Panacea Project tool to evaluate confidence in evidence. Eight randomized controlled trials, 9 nonrandomized observational studies, and 24 case reports were identified, with >3054 total participants, >1606 of whom used lamotrigine. One randomized trial of older patients found an average QRS increase of 3.5 +/− 13.1 ms. Fifteen studies reported no changes in ECG parameters. Case reports documented QRS widening (13), Brugada syndrome (6), QTc prolongation (1) and SCD (2), though many ingested toxic quantities of lamotrigine and/or other medications. Evidence is insufficient to support the breadth of the FDA warning concerning lamotrigine's cardiac risk. Lamotrigine at therapeutic doses may be associated with modest, non-dangerous QRS widening. [ABSTRACT FROM AUTHOR]

Being non-invasive, cheap and widely available, the 12-lead electrocardiogram (ECG) is a standard method to assess cardiac function. Still, its reliable interpretation requires specialized knowledge and experience, rendering a second opinion valuable. We evaluated the performance of machine learning based classification of 11,705 healthy and bundle branch block 12-lead ECGs from 3 open databases. For each lead of the ECG signal, a representative QRS-complex template was extracted automatically. Principal component analysis (PCA) was applied to the concatenated, normalized and rescaled QRS signals to reduce their dimensionality. Multilayer perceptron and support-vector machine classifiers were trained using the principal components of weighted and non-weighted QRS template signals as input data. Classifiers achieved F1 scores between 0.92 and 0.96 on the test set for different input configurations. Anomaly based weighting slightly improved the performance of the classifiers. Neither class-wise PCA for feature extraction nor adding information on sex, gender and electrical heart axis to the input data yielded considerable improvement of the F1 scores. The achieved classification accuracy is similar to deep learning classifier performances and should generalize robustly to other ECG datasets. Our results suggest that this simple and well interpretable approach based on morphological signal characteristics is suitable for automatically and non-invasively identifying bundle branch block pathologies in clinical or smart electronics contexts.

Background: Sites participating in clinical trials may not have the expertise and infrastructure to accurately measure cardiac intervals on 12-lead ECGs and rely heavily on the automated ECG device generated results for clinical decision-making. Methods: Using a dataset of over 260,000 ECGs collected in clinical oncology studies, we investigated the mean difference and the rate of false negative results between the digital ECG machine QTc and QRS measurements compared to those obtained by a centralized ECG core lab. Results: The mean differences between the core lab and the automated algorithm QTcF and QRS measurements were + 1.8 ± 16.0 ms and − 1.0 ± 8.8 ms, respectively. Among the ECGs with a centralized QTcF value > 450 or > 470 ms, 39.5% and 47.8% respectively had a device reported QTcF value ≤ 450 ms or ≤ 470 ms. Among the ECGs with a centrally measured QTcF > 500 ms, 55.8% had a device reported value ≤ 500 ms. Automated QTcF measurements failed to detect a QTcF increase > 60 ms for 53.9% of the ECGs identified by the core lab. Automated measurements also failed to detect QRS prolongation, though to a lesser extent than failures to detect QTc prolongation. Among the ECGs with a centrally measured QRS > 110 or 120 ms, 7.9% and 7.3% respectively had a device reported QRS value ≤ 110 ms or ≤ 120 ms. Conclusion: Relying on automated measurements from ECG devices for patient inclusion and treatment (dis)continuation decisions poses a potential risk to patients participating in oncology studies. [ABSTRACT FROM AUTHOR]

Background: Fetal heart rate (FHR) extracted from abdominal electrocardiogram (ECG) is a powerful non-invasive method in appropriately assessing the fetus well-being during pregnancy. Despite significant advances in the field of electrocardiography, the analysis of fetal ECG (FECG) signal is considered a challenging issue which is mainly due to low signal to noise ratio (SNR) of FECG.Objective: In this study, we present an approach for accurately locating the fetal QRS complexes in non-invasive FECG.Materials and Methods: In this experimental study, the proposed method included 4 steps. In step 1, comb notching filter was employed to pre-process the abdominal ECG (AECG). Furthermore, low frequency noises were omitted using wavelet decomposition. In next step, principal component analysis (PCA) and signal quality assessment (SQA) were used to obtain an optimal AECG reference channel for maternal R-peaks detection. In step 3, maternal ECG (MECG) was removed from mixture signal and FECG was extracted. In final step, the extracted FECG was first decomposed by discrete wavelet transforms at level 10. Then, by employing details of levels 2, 3, 4, the new FECG signal was reconstructed in which various noises and artifacts were removed and FECG components whose frequency were close to the fetal QRS complexes remained which increased the performance of the method.Results: For evaluation, 15 recordings of PhysioNet Noninvasive FECG database were used and the average F1 measure of 98.77% was obtained. Conclusion: The results indicate that use of both an efficient analysis of major component of AECG along with a signal quality assessment technique has a promising performance in FECG analysis.

Background/Aim: The anatomic location of the heart in the mediastinal space may change and significant electrophysiological changes may appear after pneumonectomy, lobectomy, and segmentectomy. The aim of the present study was to perform a comprehensive investigation of electrocardiographic alterations after lung resection. Methods: In this retrospective cohort study, sixty-six patients (9 females, 57 males) who had lung resections were enrolled. Electrocardiograms of preoperative (24 hours before operation) and postoperative periods (after operation 7 (2) days) were analyzed. Result: Postoperative mean Pmin and QRS duration levels were lower than the respective preoperative values. In comparison with preoperative values, postoperative mean P dispersion, QTmax, QTmin, QT mean, QTd, QTc, QTc dispersion, JT, JTc, mean Tpe/QTmean, mean Tpe/QTc ratio (%), and mean Tpe/JT ratio (%) levels were found to be significantly higher. Postoperative mean pulse, mean Pmax, mean PR interval, mean RR, and mean Tpe/JTc ratio were not significantly different when compared with preoperative levels. Conclusion: Alterations in electrocardiography parameters reflecting the electrophysiology of the heart since heart position basically changes after lung resection may appear. [ABSTRACT FROM AUTHOR]

This study proposes a convolutional neural network (CNN)-based identity recognition scheme using electrocardiogram (ECG) at different water temperatures (WTs) during bathing, aiming to explore the impact of ECG length on the recognition rate. ECG data was collected using non-contact electrodes at five different WTs during bathing. Ten young student subjects (seven men and three women) participated in data collection. Three ECG recordings were collected at each preset bathtub WT for each subject. Each recording is 18 min long, with a sampling rate of 200 Hz. In total, 150 ECG recordings and 150 WT recordings were collected. The R peaks were detected based on the processed ECG (baseline wandering eliminated, 50-Hz hum removed, ECG smoothing and ECG normalization) and the QRS complex waves were segmented. These segmented waves were then transformed into binary images, which served as the datasets. For each subject, the training, validation, and test data were taken from the first, second, and third ECG recordings, respectively. The number of training and validation images was 84297 and 83734, respectively. In the test stage, the preliminary classification results were obtained using the trained CNN model, and the finer classification results were determined using the majority vote method based on the preliminary results. The validation rate was 98.71%. The recognition rates were 95.00% and 98.00% when the number of test heartbeats was 7 and 17, respectively, for each subject. [ABSTRACT FROM AUTHOR]

BackgroundMyocardial mass is a key determinant of cardiac muscle function and hypertrophy. Myocardial depolarization leading to cardiac muscle contraction is reflected by the amplitude and duration of the QRS complex on the electrocardiogram (ECG). Abnormal QRS amplitude or duration reflect changes in myocardial mass and conduction, and are associated with increased risk of heart failure and death.ObjectivesThis meta-analysis sought to gain insights into the genetic determinants of myocardial mass.MethodsWe carried out a genome-wide association meta-analysis of 4 QRS traits in up to 73,518 individuals of European ancestry, followed by extensive biological and functional assessment.ResultsWe identified 52 genomic loci, of which 32 are novel, that are reliably associated with 1 or more QRS phenotypes at p < 1 × 10(-8). These loci are enriched in regions of open chromatin, histone modifications, and transcription factor binding, suggesting that they represent regions of the genome that are actively transcribed in the human heart. Pathway analyses provided evidence that these loci play a role in cardiac hypertrophy. We further highlighted 67 candidate genes at the identified loci that are preferentially expressed in cardiac tissue and associated with cardiac abnormalities in Drosophila melanogaster and Mus musculus. We validated the regulatory function of a novel variant in the SCN5A/SCN10A locus in vitro and in vivo.ConclusionsTaken together, our findings provide new insights into genes and biological pathways controlling myocardial mass and may help identify novel therapeutic targets.

Aims: The objectives were to determine the effect of NaHCO3 and/or mechanical ventilation on the biochemical profile and serum alkalinisation in tricyclic antidepressant (TCA) poisoning and investigate the impact of effective alkalinisation therapy on the QRS interval in TCA poisoning. Methods: This was a retrospective review of TCA poisonings from three Australian toxicology units and a poisons information centre (Jan 2013 to Jan 2019). We included patients with TCA toxicity who ingested>10 mg/kg or had clinically significant toxicities consistent with TCA poisoning, and analysed patients' clinical, electrocardiogram and biochemical data. Results: Of 210 patients, 84 received NaHCO3 and ventilation (dual therapy), 12 NaHCO3, 46 ventilation and 68 supportive care treatment. When compared with single/supportive groups, patients who received dual therapy had taken a significantly higher median dose of TCA (1.5 g vs1.3 g, P <.001), a longer median maximum QRS interval (124 ms, interquartile ranges [IQR] 108‐138 vs106 ms, IQR 98‐115, P <.001) and were more likely to have seizures (14% vs3%, P =.006) and arrhythmias (17% vs1%, P <.001). The dual therapy group demonstrated greater increases in serum pH (median 0.11, IQR 0.04‐0.17) compared to the single/supportive therapy group (median 0.03, IQR −0.01‐0.09, p <.001). A greater proportion of patients reached the target pH 7.45‐7.55 in the dual therapy group (59%) compared to the single/supportive therapy group (10%) (P <.001). For each 100 mmol bolus of NaHCO3 given, the median increase in serum sodium was 2.5 mmol/L (IQR 1.5‐4.0). QRS narrowing occurred twice as quickly in the dual therapy vs single/supportive therapy group. Conclusions: A combination of NaHCO3 and mechanical ventilation was most effective in achieving serum alkalinisation and was associated with a more rapid narrowing of the QRS interval. We advise that the maximal dose of NaHCO3 should be <400 mmol (6 mmol/kg). [ABSTRACT FROM AUTHOR]

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Mohammad Hosein Yazdanpanah,1,2 Sepideh Sayyadipoor,2 Sayed Reza Hojati,2 Amirreza Nikmanesh,2 Mojtaba Farjam,1 Reza Homayounfar1,3 1Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran; 2Student Research Committee, Fasa University of Medical Sciences, Fasa, Iran; 3National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, IranCorrespondence: Reza HomayounfarNoncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, IranTel +989125140840Email r_homayounfar@yahoo.comBackground: Metabolic syndrome (MetS) as a set of cardiac risk factors and its growing prevalence is one of the major concerns in different societies. In this study, we aimed to investigate the relationship between Mets and electrocardiogram (ECG) parameters and abnormalities as indicators for subclinical cardiovascular diseases (CVD).Methods: In this sub-analysis study, we used the data from Fasa PERSIAN Cohort Study which includes subjects age 35– 70 years. Subjects with available ECG data included in the study (n=7002) and subjects with missing data on MetS components and non-sinus rhythm ECG were excluded (n=44). The MetS definition based on the Adult Treatment Panel (ATP) III guidelines and also a 12-lead ECG was obtained from all participants.Results: Our study population (n=6958) showed a mean age of 48.60± 9.34 years and also 1656 (24.2%) subjects had MetS. Except for P duration, PR interval and S amplitude in men and P amplitude, S amplitude, Sokolow-Lyon Index, and QT interval in women, other ECG parameters differ significantly between subjects with and without Mets (P< 0.05). Also among ECG abnormalities, prolonged P duration (≥ 120ms), QRS duration (≥ 100ms), and QTc interval (> 450ms in male, > 470ms in female) had a significant association with MetS in the total population. Waist circumferences (WC) showed the most count of significant relationship with ECG parameters in both genders. In males, WC more than ATP cut-points had significant associations with prolonged P and QRS duration, and also blood pressure (BP) had significant associations with prolonged P and QRS durations and QTc interval. In females, the MetS component except triglyceride had at least a significant relationship with prolonged P and/or QRS duration.Conclusion: MetS and its component especially WC and BP were associated with ECG parameters and abnormalities. These associations with ECG as a marker of subclinical CVD showed the importance of MetS and each component in our population to monitor in the further longitudinal studies.Keywords: electrocardiogram, metabolic syndrome, P wave, QRS complex, QTc interval

Introduction: Cardiac resynchronization therapy (CRT) has rapidly evolved as a standard therapy for heart failure (HF) patients. Higher levels of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are typically used in the diagnosis of HF. Materials and Methods: A prospective, observational study of 60 patients with CRT was evaluated with clinical, laboratory and echocardiographic parameters. All patients underwent clinical examination, 6-min walk test, 12-lead electrocardiogram, two-dimensional echocardiographic with Doppler evaluations and NT-proBNP determination. Results: After effective CRT in patients, there was significant improvements in New York Heart Association functional class and 6-min walked distance along with significant decrease in mean QRS width and NT-proBNP plasma levels at 3 and 6 months' follow-up (P < 0.05). The repeat echocardiogram at 3 and 6 months' follow-up showed a significant reduction in the left ventricular end-systolic volume, left ventricular end diastolic volume, and significant left ventricular ejection fraction (LVEF) improvement (P < 0.05). No significant reduction in left ventricle (LV) diameters over 3 and 6 months' follow-up with a significant reduction in the MR severity after 6 months were observed (P < 0.05). At 6 months' follow-up, 75% patients (n = 45) were responders showing concordance between clinical, echocardiographic and NT-proBNP definitions of CRT response while 25% patients (n = 15) were nonresponders. The change in NT-proBNP levels between pre-CRT and 6 months' post CRT was significantly more important in responders than in nonresponders (P < 0.001). Conclusion: The present study shows the clinical benefit of treating patients with CRT and points to the reverse ventricular remodeling, with sustained decrease in LV volumes, plasma NT-proBNP, increase in LVEF, and decrease of the severity of mitral valve regurgitation.

Background QRS duration (QRSd) is a marker of electrical remodeling in heart failure. Anthropometrics and left ventricular size may influence QRSd and, in turn, may influence the association between QRSd and heart failure outcomes. Methods and Results Using the prospective, multicenter, multinational ASIAN‐HF (Asian Sudden Cardiac Death in Heart Failure) registry, this study evaluated whether electroanatomic ratios (QRSd indexed for height or left ventricular end‐diastole volume) are associated with 1‐year mortality in individuals with heart failure with reduced ejection fraction. The study included 4899 individuals (aged 60±19 years, 78% male, mean left ventricular ejection fraction: 27.3±7.1%). In the overall cohort, QRSd was not associated with all‐cause mortality (hazard ratio [HR], 1.003; 95% CI, 0.999–1.006, P=0.142) or sudden cardiac death (HR, 1.006; 95% CI, 1.000–1.013, P=0.059). QRS/height was associated with all‐cause mortality (HR, 1.165; 95% CI, 1.046–1.296, P=0.005 with interaction by sex pinteraction=0.020) and sudden cardiac death (HR, 1.270; 95% CI, 1.021–1.580, P=0.032). QRS/left ventricular end‐diastole volume was associated with all‐cause mortality (HR, 1.22; 95% CI, 1.05–1.43, P=0.011) and sudden cardiac death (HR, 1.461; 95% CI, 1.090–1.957, P=0.011) in patients with nonischemic cardiomyopathy but not in patients with ischemic cardiomyopathy (all‐cause mortality: HR, 0.94; 95% CI, 0.79–1.11, P=0.467; sudden cardiac death: HR, 0.734; 95% CI, 0.477–1.132, P=0.162). Conclusions Electroanatomic ratios of QRSd indexed for body size or left ventricular size are associated with mortality in individuals with heart failure with reduced ejection fraction. In particular, increased QRS/height may be a marker of high risk in individuals with heart failure with reduced ejection fraction, and QRS/left ventricular end‐diastole volume may further risk stratify individuals with nonischemic heart failure with reduced ejection fraction. Registration URL: https://Clinicaltrials.gov. Unique identifier: NCT01633398.

Background: Fetal heart rate (FHR) extracted from abdominal electrocardiogram (ECG) is a powerful non-invasive method in appropriately assessing the fetus wellbeing during pregnancy. Despite significant advances in the field of electrocardiography, the analysis of fetal ECG (FECG) signal is considered a challenging issue which is mainly due to low signal to noise ratio (SNR) of FECG. Objective: In this study, we present an approach for accurately locating the fetal QRS complexes in non-invasive FECG. Materials and Methods: In this experimental study, the proposed method included 4 steps. In step 1, comb notching filter was employed to pre-process the abdominal ECG (AECG). Furthermore, low frequency noises were omitted using wavelet decomposition. In next step, principal component analysis (PCA) and signal quality assessment (SQA) were used to obtain an optimal AECG reference channel for maternal R-peaks detection. In step 3, maternal ECG (MECG) was removed from mixture signal and FECG was extracted. In final step, the extracted FECG was first decomposed by discrete wavelet transforms at level 10. Then, by employing details of levels 2, 3, 4, the new FECG signal was reconstructed in which various noises and artifacts were removed and FECG components whose frequency were close to the fetal QRS complexes remained which increased the performance of the method. Results: For evaluation, 15 recordings of PhysioNet Noninvasive FECG database were used and the average F1 measure of 98.77% was obtained. Conclusion: The results indicate that use of both an efficient analysis of major component of AECG along with a signal quality assessment technique has a promising performance in FECG analysis. [ABSTRACT FROM AUTHOR]

Introduction: Right ventricular (RV) pacing sometimes causes left ventricular (LV) systolic dysfunction, also known as pacing-induced cardiomyopathy (PICM). However, the association between specifically paced QRS morphology and PICM development has not been elucidated. This study aimed to investigate the association between paced QRS mimicking a complete left bundle branch block (CLBBB) and PICM development., Methods: We retrospectively screened 2009 patients who underwent pacemaker implantation from 2010 to 2020 in seven institutions. Patients who received pacemakers for an advanced atrioventricular block or bradycardia with atrial fibrillation, baseline LV ejection fraction (LVEF) ≥ 50%, and echocardiogram recorded at least 6 months postimplantation were included. The paced QRS recorded immediately after implantation was analyzed. A CLBBB-like paced QRS was defined as meeting the CLBBB criteria of the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society in 2009. PICM was defined as a ≥10% LVEF decrease, resulting in an LVEF of <50%., Results: Among the 270 patients analyzed, PICM was observed in 38. Baseline LVEF was lower in patients with PICM, and CLBBB-like paced QRS was frequently observed in PICM. Multivariate analysis revealed that low baseline LVEF (odds ratio [OR]: 0.93 per 1% increase, 95% confidence interval [CI]: 0.89-0.98, p = 0.006) and CLBBB-like paced QRS (OR: 2.69, 95% CI: 1.25-5.76, p = 0.011) were significantly associated with PICM development., Conclusion: CLBBB-like paced QRS may be a novel risk factor for PICM. RV pacing, which causes CLBBB-like QRS morphology, may need to be avoided, and patients with CLBBB-like paced QRS should be followed-up carefully., (© 2024 Wiley Periodicals LLC.)

The online telemedicine systems are helpful since they provide timely and effective healthcare services. Such online healthcare systems are usually based on sophisticated and advanced wearable and wireless sensor technologies. A rapid technological growth has improved the scope of many remote health monitoring systems. Here, the researchers employed a cloud-based remote monitoring system for observing the health status of the patients after monitoring their heart rate variability. This system was developed after considering many factors like the ease of application, costs, accuracy, and the data security. Furthermore, this system was also conceptualized to act as an interface between the patients and the healthcare providers, thus ensuring a two-way communication between them. The major aim of this paper was to provide the best healthcare monitoring services to the people living in the remote areas, which was otherwise very difficult owing to the small doctor-to-patient ratio. The researchers also analyzed their monitoring system using two different databases. First comes from MIT Physionet database i.e., the MIT-BIH sinus rhythm and the MIT-St. Petersburg. While the second database was collected after monitoring 30 people who were asked to use these wearable sensors. After analyzing the performance of the proposed scheme, the obtained results for accuracy, sensitivity, and specificity were 99.02%, 98.78%, and 99.17%, respectively. The achieved results concluded that the proposed system was quite reliable, robust, and valuable. Also, the data analysis revealed that this system was very convenient and ensured data security. In addition, this developed monitoring system generated warning messages, directed towards the patients and the doctors, during some critical situation.

Legacy studies for classifying arrhythmia have been studied in order to improve the accuracy of classification, Neural Network, Fuzzy, Machine Learning, etc. In particular, deep learning is most frequently used for arrhythmia classification using error backpropagation algorithm by solving the limit of hidden layer number, which is a problem of neural network. In order to apply a deep learning model to an ECG signal, it is necessary to select an optimal model and parameters. In this paper, we propose parameter extraction based on AR and arrhythmia classification through a deep learning. For this purpose, the R-wave is detected in the ECG signal from which noise has been removed, QRS and RR interval is modelled. And then, the weights were learned by supervised learning method through deep learning and the model was evaluated by the verification data. The classification rate of PVC is evaluated through MIT-BIH arrhythmia database. The achieved scores indicate arrhythmia classification rate of over 97%. [ABSTRACT FROM AUTHOR]

OBJECTIVES Timing of pulmonary valve replacement (PVR) remains one of the most heavily debated topics in congenital cardiac surgery. We aimed to analyse the temporal evolution of QRS duration before and after PVR. METHODS We included 158 consecutive patients who underwent PVR after previous correction with transannular patch. All 3549 available serial standard 12-lead surface QRS measurements of 158 (100%) patients were analysed with linear mixed-effect modelling. RESULTS PVR was performed at a mean age of 28.0 ± 10.7 years, 23.4 ± 8.4 years after correction. Hospital survival was 98.1%. A longer time interval between ToF correction and PVR (P  < 0.001), and an older age at correction (P  = 0.015) were predictive of progressive QRS prolongation after PVR. Women on average had a shorter QRS duration (P  = 0.005) after PVR. The model predicted that in patients corrected early (model age 0.5 years), PVR within 17 years after correction leads to narrowing or stabilization of QRS width. PVR beyond 17 years was associated with prolongation of QRS duration. In a patient corrected late (model age 5 years), PVR has to be performed within 15 years after correction to prevent prolongation. Finally, a longer time period between correction and PVR was associated with an increased hazard of cardiac death (hazard ratio 1.097, 95% confidence interval 1.002–1.200). CONCLUSIONS Prolongation of QRS duration after PVR was associated with a longer time between correction and PVR, older age at correction and male sex. Prevention of progressive QRS prolongation by earlier PVR can potentially reduce the hazard of adverse events after PVR. [ABSTRACT FROM AUTHOR]

Electrocardiogram (ECG) is one of the major methods for the diagnosis of heart malfunctions. ECG signals are susceptible to both high-frequency and low-frequency noises such as electromyography (EMG), power line interference (PLI) and baseline wander noises, respectively. These noises deteriorate the quality of ECG signals and challenge the proper identification of heart illnesses. In this article, we report an improved fully adaptive method for canceling high-frequency noises using the empirical mode decomposition (EMD) with the modified indirect subtraction and adaptive window techniques. As high-frequency noises are approximately of zero mean and lower-order intrinsic mode functions (IMFs) contain high-frequency noises, a statistical test is performed to determine whether a particular combination of IMFs has zero mean. First, to remove the PLI noise, the modified indirect subtraction technique is used. The sum of IMFs which are dominated by the noise is passed to a Butterworth band-pass filter, and the resultant filtered signal is subtracted directly from the noisy ECG signal. Then, the EMG noise is removed by an improved adaptive window-based noise reduction technique. By exploiting this technique, in contrast to common EMD-based methods, the duration of the QRS complex is computed regarding the location of the peak of the R wave and the widest possible QRS complex which makes the proposed technique applicable to all types of ECG signals. The quantitative results of simulations performed on several records from the MIT–BIH arrhythmia database prove the better performance of the proposed method than the compared methods at different noise levels. [ABSTRACT FROM AUTHOR]

Introduction: Cardiac resynchronization therapy (CRT) has rapidly evolved as a standard therapy for heart failure (HF) patients. Higher levels of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are typically used in the diagnosis of HF. Materials and Methods: A prospective, observational study of 60 patients with CRT was evaluated with clinical, laboratory and echocardiographic parameters. All patients underwent clinical examination, 6-min walk test, 12-lead electrocardiogram, two-dimensional echocardiographic with Doppler evaluations and NT-proBNP determination. Results: After effective CRT in patients, there was significant improvements in New York Heart Association functional class and 6-min walked distance along with significant decrease in mean QRS width and NT-proBNP plasma levels at 3 and 6 months' follow-up (P < 0.05). The repeat echocardiogram at 3 and 6 months' follow-up showed a significant reduction in the left ventricular end-systolic volume, left ventricular end diastolic volume, and significant left ventricular ejection fraction (LVEF) improvement (P < 0.05). No significant reduction in left ventricle (LV) diameters over 3 and 6 months' follow-up with a significant reduction in the MR severity after 6 months were observed (P < 0.05). At 6 months' follow-up, 75% patients (n = 45) were responders showing concordance between clinical, echocardiographic and NT-proBNP definitions of CRT response while 25% patients (n = 15) were nonresponders. The change in NT-proBNP levels between pre-CRT and 6 months' post CRT was significantly more important in responders than in nonresponders (P < 0.001). Conclusion: The present study shows the clinical benefit of treating patients with CRT and points to the reverse ventricular remodeling, with sustained decrease in LV volumes, plasma NT-proBNP, increase in LVEF, and decrease of the severity of mitral valve regurgitation. [ABSTRACT FROM AUTHOR]

Electrocardiography is the principle of recording the electrical activity of the heart over finite duration of time. It is one of the most practiced methods to detect abnormalities in the heart's electrical, arterial and muscular systems. Electrocardiogram is the voltage versus time graph obtained from the Electrocardiography machine. Automated analysis makes detection of Electrocardiogram findings and consequently determination of pathological abnormalities without human intervention possible. To achieve this goal we process digital Electrocardiograms to quantify the amplitudes and durations of waves and intervals, that is necessary for the automated analysis to find the pathological abnormalities. The proposed method processes Electrocardiograms and localizes the P, Q, R, S and T waves, subsequently it measures the PR, QT and ST intervals and segments. [ABSTRACT FROM AUTHOR]

QRS represented the most important part of ECG signal, so different researches and studies are performed for QRS recognition. In this paper, a new technique by using wavelet transform is used for denoising ECG signal by using adaptive threshold, then DWT used to separate the high frequency from the low component, then compute the statistical information from low frequencies to be used in threshold computation, Based on these statics features, lower and upper threshold are calculated, which are updated according to number of peaks that are detected until two thresholds give same number of peaks, also the detected peaks are updated according to average R-R time. Results of (EDB) database was (Acc = 99.366%), while (LTSTDB) database was (Acc = 98.89%). The results are compared with other work and it is show that the proposed method gave better performance and can be used for QRS detection. [ABSTRACT FROM AUTHOR]

Legacy studies for classifying arrhythmia have been studied to improve the accuracy of classification, Neural Network, Fuzzy, etc. Deep learning is most frequently used for arrhythmia classification using error backpropagation algorithm by solving the limit of hidden layer number, which is a problem of neural network. In order to apply a deep learning model to an ECG signal, it is necessary to select an optimal model and parameters. In this paper, we propose optimal parameter extraction method based on a deep learning. For this purpose, R-wave is detected in the ECG signal from which noise has been removed, QRS and RR interval segment is modelled. And then, the weights were learned by supervised learning method through deep learning and the model was evaluated by the verification data. The detection and classification rate of R wave and PVC is evaluated through MIT-BIH arrhythmia database. The performance results indicate the average of 99.77% in R wave detection and 97.84% in PVC classification. [ABSTRACT FROM AUTHOR]