Assessment of ventricular electrical heterogeneity in left bundle branch pacing and left ventricular septal pacing by using various electrophysiological methods.

Introduction: Left bundle branch area pacing (LBBAP) comprises pacing at the left ventricular septum (LVSP) or left bundle branch (LBBP). The aim of the present study was to investigate the differences in ventricular electrical heterogeneity between LVSP, LBBP, right ventricular pacing (RVP) and intrinsic conduction with different dyssynchrony measures using the ECG, vectorcardiograpy, ECG belt, and Ultrahigh frequency (UHF-)ECG.

Methods: Thirty-seven patients with a pacemaker indication for bradycardia or cardiac resynchronization therapy underwent LBBAP implantation.

Ineffective cardiac resynchronization pacing is associated with poor outcomes in a nationwide cohort analysis.

Background: Delivery of cardiac resynchronization therapy (CRT) requires left ventricular myocardial capture to achieve clinical benefits.

Objective: We sought to determine whether ineffective pacing affects survival.

Methods: Ineffective ventricular pacing (VP) was defined as the difference between the percentage of delivered CRT (%VP) and the percentage of effective CRT in CRT devices.

Electrocardiogram Belt guidance for left ventricular lead placement and biventricular pacing optimization.

Background: Patients with ischemic cardiomyopathy, non-left bundle branch block, or QRS duration <150 ms have a lower response rate to cardiac resynchronization therapy (CRT) than did other indicated patients. The ECG Belt system (EBS) is a novel surface mapping system designed to measure electrical dyssynchrony via the standard deviation of the activation times of the left ventricle.

Objectives: The objectives of this study were to evaluate the efficacy of the EBS in patients less likely to respond to CRT and to determine whether EBS use in lead placement guidance and device programming was superior to standard CRT care.

Non-invasive assessment of ventricular electrical heterogeneity to optimize left bundle branch area pacing.

Background: Left bundle branch area pacing (LBBAP) is a novel therapeutic option for bradycardia and heart failure patients. ECG belt is a novel technology for assessment of ventricular electrical heterogeneity (VEH) using multi-electrode ECG. A metric of overall VEH based on standard deviation of activation times (SDAT) from all electrodes in the ECG belt has been previously shown to predict cardiac resynchronization therapy (CRT) response.

Design, molecular docking, drug-likeness, and molecular dynamics studies of 1,2,4-trioxane derivatives as novel falcipain-2 (FP-2) inhibitors.

Despite significant progress made in drug discovery and development over the past few decades, malaria remains a life-threatening infectious disease across the globe. Because of the widespread emergence of drug-resistant strains of , the clinical utility of existing drug therapies including Artemisinin-based Combination Therapies (ACTs) in the treatment of malaria has been increasingly limited. It has become a serious health concern which, therefore, necessitates the development of novel drug molecules and/or alternative therapies to combat, particularly resistant .

Comparison of electrical dyssynchrony parameters between electrocardiographic imaging and a simulated ECG belt.

Aims: Electrocardiographic imaging (ECGi) and the ECG belt are body surface potential mapping systems which can assess electrical dyssynchrony in patients undergoing cardiac resynchronization therapy (CRT). ECGi-derived dyssynchrony metrics are calculated from reconstructed epicardial potentials based on body surface potentials combined with a thoracic CT scan, while the ECG belt relies on body surface potentials alone. The relationship between dyssynchrony metrics from these two systems is unknown.

Impact of Mg and Al Substitutions on the Structural and Electrochemical Properties of NASICON-Na VMn M (PO ) (M = Mg and Al) Cathodes for Sodium-Ion Batteries.

Sodium superionic conductor (NASICON)-Na VMn(PO ) (NVMP) cathode is attractive for sodium-ion battery application due to its reduced cost and toxicity, and high energy density (≈425 Wh kg ). However, it exhibits significant polarization, limited rate and cycling performances due to its lower electronic conductivity and formation of Jahn-Teller active Mn during cycling. In this report, a chemical approach is presented to partially replace Mn of the NVMP framework by Mg and Al substitutions.

The ECG Belt for CRT response trial: Design and clinical protocol.

The ECG Belt for CRT response trial is designed to test the hypothesis that in patients traditionally less likely to respond to cardiac resynchronization therapy (CRT), an individualized approach utilizing the electrocardiogram (ECG) Belt to guide lead placement, vector selection, and device programming is superior to current standard of care. The ECG Belt is a noninvasive mapping technology designed to measure beat by beat electrical activation of the left ventricle by utilizing unipolar measurements from multiple ECG electrodes on the body surface. The ECG Belt for CRT response trial is a multicenter, prospective, randomized, investigational pre-market research study conducted at 48 centers in the United States, Canada, and Europe and will randomize approximately 400 subjects.

Short-Term Hemodynamic and Electrophysiological Effects of Cardiac Resynchronization by Left Ventricular Septal Pacing.

Background: Cardiac resynchronization therapy (CRT) is usually performed by biventricular (BiV) pacing. Previously, feasibility of transvenous implantation of a lead at the left ventricular (LV) endocardial side of the interventricular septum, referred to as LV septal (LVs) pacing, was demonstrated.

Objectives: The authors sought to compare the acute electrophysiological and hemodynamic effects of LVs with BiV and His bundle (HB) pacing in CRT patients.

Twelve-Lead ECG Optimization of Cardiac Resynchronization Therapy in Patients With and Without Delayed Enhancement on Cardiac Magnetic Resonance Imaging.

Background Delayed enhancement ( DE ) on magnetic resonance imaging is associated with ventricular arrhythmias, adverse events, and worse left ventricular mechanics. We investigated the impact of DE on cardiac resynchronization therapy ( CRT ) outcomes and the effect of CRT optimization. Methods and Results We studied 130 patients with ejection fraction ( EF ) ≤40% and QRS ≥120 ms, contrast cardiac magnetic resonance imaging, and both pre- and 1-year post- CRT echocardiograms.

Body surface activation mapping of electrical dyssynchrony in cardiac resynchronization therapy patients: Potential for optimization.

Background: Electrical synchronization is likely improved by cardiac resynchronization therapy (CRT), but is difficult to quantify with 12-lead ECG. We aimed to quantify changes in electrical synchrony and potential for optimization with CRT using a body-surface activation mapping (BSAM) system.

Methods: Standard deviation of activation times (SDAT) was calculated in 94 patients using BSAM at baseline CRT (CRT), native, and different CRT configurations.

A novel algorithm increases the delivery of effective cardiac resynchronization therapy during atrial fibrillation: The CRTee randomized crossover trial.

Background: Cardiac resynchronization therapy (CRT) requires a high percentage of ventricular pacing (%Vp) to maximize its clinical benefits. Atrial fibrillation (AF) has been shown to reduce %Vp in CRT due to competition with irregular intrinsic atrioventricular (AV) conduction. We report the results of a prospective randomized crossover trial evaluating the amount of effective CRT delivered during AF with a novel algorithm (eCRTAF).

Device pacing diagnostics overestimate effective cardiac resynchronization therapy pacing results of the hOLter for Efficacy analysis of CRT (OLÉ CRT) study.

Background: A high percentage of biventricular (BiV) or left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) devices has been associated with superior clinical outcomes. However, the percent ventricular (%V) pacing reported by CRT devices simply indicates the number of paces the device has delivered and not the proportion of pacing that has captured the LV effectively.

Objective: The purpose of this study was to determine whether a beat-by-beat evaluation of effective pacing would provide a more accurate evaluation of CRT delivery.

Body surface mapping using an ECG belt to characterize electrical heterogeneity for different left ventricular pacing sites during cardiac resynchronization: Relationship with acute hemodynamic improvement.

Background: Electrical heterogeneity (EH) during cardiac resynchronization therapy may vary with different left ventricular (LV) pacing sites.

Objective: The purpose of this study was to evaluate the relationship between such changes and acute hemodynamic response (AHR).

Methods: Two EH metrics-standard deviation of activation times and mean left thorax activation times-were computed from isochronal maps based on 53-electrode body surface mapping during baseline AAI pacing and biventricular (BiV) pacing from different pacing sites in coronary veins in 40 cardiac resynchronization therapy-indicated patients.

Changes in electrical dyssynchrony by body surface mapping predict left ventricular remodeling in patients with cardiac resynchronization therapy.

Background: Electrical activation is important in cardiac resynchronization therapy (CRT) response. Standard electrocardiographic analysis may not accurately reflect the heterogeneity of electrical activation.

Objective: We compared changes in left ventricular size and function after CRT to native electrical dyssynchrony and its change during pacing.

Influence of automatic frequent pace-timing adjustments on effective left ventricular pacing during cardiac resynchronization therapy.

Aims: Cardiac resynchronization therapy (CRT) requires effective left ventricular (LV) pacing (i.e. sufficient energy and appropriate timing to capture).

Automated detection of effective left-ventricular pacing: going beyond percentage pacing counters.

Aims: Cardiac resynchronization therapy (CRT) devices report percentage pacing as a diagnostic but cannot determine the effectiveness of each paced beat in capturing left-ventricular (LV) myocardium. Reasons for ineffective LV pacing include improper timing (i.e.

Electrophysiologic substrate and intraventricular left ventricular dyssynchrony in nonischemic heart failure patients undergoing cardiac resynchronization therapy.

Background: Electrocardiographic imaging (ECGI) is a method for noninvasive epicardial electrophysiologic mapping. ECGI previously has been used to characterize the electrophysiologic substrate and electrical synchrony in a very heterogeneous group of patients with varying degrees of coronary disease and ischemic cardiomyopathy.

Objective: The purpose of this study was to characterize the left ventricular electrophysiologic substrate and electrical dyssynchrony using ECGI in a homogeneous group of nonischemic cardiomyopathy patients who were previously implanted with a cardiac resynchronization therapy (CRT) device.

Cardiac resynchronization therapy in pediatric congenital heart disease: insights from noninvasive electrocardiographic imaging.

Background: Electrocardiographic imaging (ECGI) is a novel electrophysiologic imaging modality that may help guide patient selection and lead placement for cardiac resynchronization therapy (CRT).

Objective: The purpose of this study was to apply noninvasive ECGI to pediatric heart failure patients with congenital heart disease (CHD) undergoing evaluation for CRT.

Methods: ECGI was applied in eight patients with CHD who were either being evaluated for CRT or undergoing CRT.

Application of L1-norm regularization to epicardial potential solution of the inverse electrocardiography problem.

The electrocardiographic inverse problem of computing epicardial potentials from multi-electrode body-surface ECG measurements, is an ill-posed problem. Tikhonov regularization is commonly employed, which imposes penalty on the L2-norm of the potentials (zero-order) or their derivatives. Previous work has indicated superior results using L2-norm of the normal derivative of the solution (a first order regularization).

Cardiac memory in patients with Wolff-Parkinson-White syndrome: noninvasive imaging of activation and repolarization before and after catheter ablation.

Background: Cardiac memory refers to a change in ventricular repolarization induced by and persisting for minutes to months after cessation of a period of altered ventricular activation (eg, resulting from pacing or preexcitation in patients with Wolff-Parkinson-White syndrome). ECG imaging (ECGI) is a novel imaging modality for noninvasive electroanatomic mapping of epicardial activation and repolarization.

Methods And Results: Fourteen pediatric patients with Wolff-Parkinson-White syndrome and no other congenital disease, were imaged with ECGI a day before and 45 minutes, 1 week, and 1 month after successful catheter ablation.