Electrogram

BACKGROUND: Endocardial electrogram (EGM) characteristics in non-ischemic cardiomyopathy (NICM) have not been explored adequately for prognostication. OBJECTIVES: We aim to study correlation of bipolar and unipolar EGM characteristics with left ventricular ejection fraction (LVEF) and ventricular tachycardia (VT) in NICM. METHODS: Electroanatomical mapping of LV was performed. Correlation of EGM characteristics with LVEF was performed. Differences between groups with and without VT and predictors of VT were studied...

Cardiac fibrosis stands as one of the most critical conditions leading to lethal cardiac arrhythmias. Identifying the precise location of cardiac fibrosis is crucial for planning clinical interventions in patients with various forms of ventricular and atrial arrhythmias. As fibrosis impedes and alters the path of electrical waves, detecting fibrosis in the heart can be achieved through analyzing electrical signals recorded from its surface. In current clinical practices, it has become feasible to record electrical activity from both the endocardial and epicardial surfaces of the heart...

BACKGROUND AND AIMS: A three-dimensional electroanatomic mapping system-guided transseptal puncture (3D-TSP), without fluoroscopy or echocardiography, was insufficiently reported. Indications for 3D-TSP remain unclear. This study aimed to establish a precise technique and create a workflow for validating and selecting eligible patients for fluoroless 3D-TSP. METHODS AND RESULTS: We developed a new methodology for 3D-TSP based on the unipolar electrogram derived from transseptal needle tip (UEGM-tip) in 102 cases (the derivation cohort) with intracardiac echocardiography (ICE) from March 2018 to February 2019...

Background: A jump in the atrioventricular (AV) conduction curve is the current clinical criterion of dual-pathway electrophysiology. However, the assumption that a jump indicates a switch from fast pathway (FP) to slow pathway (SP) conduction remains unconfirmed. This study was carried out to investigate whether a jump indeed indicates a transition from FP to SP conduction, and if not, what the potential cause is. Methods: Eighty-one experimental records from rabbit AV nodal preparations containing the following data were analyzed: 1) had at least one AV conduction curve and 2) had recording of His electrogram alternans (a validated new index of dual-pathway conduction)...

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INTRODUCTION: Catheter ablation of ectopy originating from the vicinity of the His bundle can be challenging. METHODS AND RESULTS: We report a case of a 33-year-old man with narrow QRS ectopy with preferential conduction from a para-Hisian origin to the proximal left fascicles, which was successfully eliminated by radiofrequency ablation in the right coronary cusp, guided by ultrahigh-resolution mapping of the His bundle, bundle branch, and fascicular electrograms...

BACKGROUND AND AIMS: Pericardiocentesis is usually completed under fluoroscopy. The electroanatomic mapping (EAM) system allows visualizing puncture needle tip (NT) while displaying the electrogram recorded from NT, making it possible to obtain epicardial access (EA) independent of fluoroscopy. This study was designed to establish and validate a technique by which EA is obtained under guidance of 3-dimensional (3D) EAM combined with NT electrogram. METHODS: 3D shell of the heart was generated and the NT was made trackable in the EAM system...

This is the first case series to evaluate high-density mapping of the triangle of Koch (TOK) using the HD Grid to guide slow-pathway ablation integrating activation, propagation (with wave collision), low-voltage signals, and atrial electrogram appearance. We will describe our technique and the results in this case series. Using three-dimensional mapping and the HD Grid, patients underwent high-density voltage mapping of the TOK. Ablation site selection was based on properties during sinus rhythm with late activation, at or above the propagation wave collision, over low voltage, and with appropriate electrogram appearance...

INTRODUCTION: Left atrial (LA) low voltage areas (LVA) are a controversial target in atrial fibrillation ablation procedures. However, LVA and LA volume are good predictors of arrhythmia recurrence in ablation-naïve patients. Their predictive value in progressively diseased pre-ablated atria is uncertain. METHODS: Consecutive patients with recurrent atrial fibrillation (AF) or atrial tachycardia (AT), who were scheduled for repeat LA ablation, were enrolled in the prospective Bernau ablation registry between 2016 and 2020...

Objective : AtriAmp is a new medical device that displays a continuous real-time atrial electrogram on telemetry using temporary atrial pacing leads. Our objective was to evaluate early adoption of this device into patient care, understand how it affected clinical workflow, and identify unforeseen benefits or limitations. Design : Qualitative study using inductive analysis of semi-structured interviews to identify dominant themes Setting : Single center, tertiary, academic 21-bed mixed pediatric intensive care unit (PICU) Subjects : PICU multidisciplinary team members (Pediatric Intensivists, PICU Nurse Practitioners, PICU nurses and Pediatric Cardiologists) who were early adopters of the AtriAmp (n=14) Results : Three prominent themes emerged from qualitative analysis of the early adopters' experiences...

BACKGROUND: Studies of VT mechanisms are largely based on a 2D portrait of reentrant circuits on one surface of the heart. This oversimplifies the 3D circuit that involves the depth of the myocardium. Simultaneous epicardial and endocardial (epi-endo) mapping was shown to facilitate a 3D delineation of VT circuits, which is however difficult via invasive mapping. OBJECTIVE: This study investigates the capability of noninvasive epicardial-endocardial electrocardiographic imaging (ECGI) to elucidate the 3D construct of VT circuits, emphasizing the differentiation of epicardial, endocardial, and intramural circuits and to determine the proximity of mid-wall exits to the epicardial or endocardial surfaces...

No abstract text is available yet for this article.

BACKGROUND: Anatomical and electrophysiological findings suggest the actual circuit of atrioventricular nodal reentrant tachycardia (AVNRT) involves the perinodal atrium. However, occasional instances where the atrium is dissociated from AVNRT have led to the concept of upper common pathways (UCP). OBJECTIVE: We aimed to assess the prevalence of UCP in AVNRT using a late atrial premature depolarization (LAPD) maneuver. METHODS: Patients who were diagnosed with typical AVNRT by electrophysiologic studies were enrolled...

Background: Pulmonary vein isolation is currently considered to be the gold standard for ablating paroxysmal atrial fibrillation. However, its efficacy is limited in patients with persistent atrial fibrillation. The convergent procedure has emerged as a hybrid ablation. This study aims, for the first time in the literature, to introduce a hybrid approach that includes epicardial ablation with cutting-edge robotic technology and subsequent electrophysiological study to verify and an endocardial ablation to complete the ablation lines...

BACKGROUND: Implantable cardioverter defibrillators (ICD) are often used as primary prevention strategy for sudden cardiac death (SCD) in young individuals. This study analyzed appropriate therapies, complications and inappropriate shocks in the real-world Indian population. METHODS: All patients in the cardiomyopathy cohort under follow up who had ICD implanted as a primary prevention strategy were studied. The objective was to assess the incidence of appropriate ICD therapies, inappropriate therapies and complications...

BACKGROUND AND OBJECTIVE: Treatment for atrial fibrillation (AF) has evolved significantly, with pulmonary vein isolation (PVI) becoming an established treatment. However, the outcomes following catheter ablation for persistent AF remain unsatisfactory. Hybrid catheter-surgical ablation has emerged as a therapeutic approach for persistent AF, combining the strengths of both interventions. The purpose of this narrative review is to comprehensively examine the current state of knowledge regarding hybrid ablation for AF...

Low-voltage areas have been used as atrial structural substrates in estimating fibrotic degeneration in patients with atrial fibrillation (AF). The high-resolution maps obtained by recently developed mapping catheters allow the visualization of several functional abnormalities. We investigated the association between left atrial (LA) functional abnormal findings on a high-resolution substrate map and AF recurrence in patients who underwent pulmonary vein isolation without any additional LA substrate ablation...

INTRODUCTION: Repolarization dispersion in the right ventricular outflow tract (RVOT) contributes to the type-1 electrocardiographic (ECG) phenotype of Brugada syndrome (BrS), while data on the significance and feasibility of mapping repolarization dispersion in BrS patients are scarce. Moreover, the role of endocardial repolarization dispersion in BrS is poorly investigated. We aimed to assess endocardial repolarization patterns through an automated calculation of activation recovery interval (ARI) estimated on unipolar electrograms (UEGs) in spontaneous type-1 BrS patients and controls; we also investigated the relation between ARI and right ventricle activation time (RVAT), and T-wave peak-to-end interval (Tpe) in BrS patients...

BACKGROUND: Optimization of atrial-ventricular delay (AVD) during atrial sensing (SAVD) and pacing (PAVD) provides the most effective cardiac resynchronization therapy (CRT). We demonstrate a novel electrocardiographic methodology for quantifying electrical synchrony and optimizing SAVD/PAVD. METHODS: We studied 40 CRT patients with LV activation delay. Atrial-sensed to RV-sensed (As-RVs) and atrial-paced to RV-sensed (Ap-RVs) intervals were measured from intracardiac electrograms (IEGM)...

Cardioneuroablation (CNA) is currently considered as a promising treatment option for patients with symptomatic bradycardia caused by vagotonia. This study aims to further investigate its safety and efficacy in patients suffering from vagal bradycardia. A total of 60 patients with vagal bradycardia who underwent CNA in the First Affiliated Hospital of Xinjiang Medical University from November 2019 to June 2022. Preoperative atropine tests revealed abnormal vagal tone elevation in all patients. First, the electroanatomic structures of the left atrium was mapped out by using the Carto 3 system, according to the protocol of purely anatomy-guided and local fractionated intracardiac electrogram-guided CNA methods...