Advancements in 3D Transoesophageal Echocardiography (TOE) and Computed Tomography (CT) for Stroke Prevention in Left Atrial Appendage Occlusion Interventions.

Left atrial appendage occlusion (LAAO) has emerged as a highly effective alternative to oral anticoagulation for stroke prevention in patients with non-valvular atrial fibrillation. Precise pre-procedural planning and meticulous post-procedural follow-up are essential for achieving successful LAAO outcomes. This review explores the latest advancements in three-dimensional (3D) transoesophageal echocardiography (TOE) and computed tomography (CT) imaging modalities, which have considerably improved the planning, intra-procedural guidance, and follow-up processes for LAAO interventions.

The arrhythmic substrate of hypertrophic cardiomyopathy using ECG imaging.

Patients with hypertrophic cardiomyopathy (HCM) are at risk for lethal ventricular arrhythmia, but the electrophysiological substrate behind this is not well-understood. We used non-invasive electrocardiographic imaging to characterize patients with HCM, including cardiac arrest survivors. HCM patients surviving ventricular fibrillation or hemodynamically unstable ventricular tachycardia (n = 17) were compared to HCM patients without a personal history of potentially lethal arrhythmia (n = 20) and a pooled control group with structurally normal hearts.

Catheter ablation for atrial fibrillation and impact on clinical outcomes.

Aims: Catheter ablation is the most effective rhythm-control option in patients with atrial fibrillation (AF) and is currently considered an option mainly for improving symptoms. We aimed to assess the impact of catheter ablation on hard clinical outcomes.

Methods And Results: We performed a systematic review of randomized controlled trials (RCTs) comparing catheter ablation vs.

Percutaneous Neuromodulation for Atrial Fibrillation.

Percutaneous neuromodulation is emerging as a promising therapeutic approach for atrial fibrillation (AF). This article explores techniques such as ganglionated plexi (GP) ablation, and vagus nerve stimulation, pinpointing their potential in modulating AF triggers and maintenance. Noninvasive methods, such as transcutaneous low-level tragus stimulation, offer innovative treatment pathways, with early trials indicating a significant reduction in AF burden.

Predictors of the efficacy of His bundle pacing in patients with a prolonged PR interval: A stratified analysis of the HOPE-HF randomized controlled trial.

Aims: The randomized, double-blind, placebo-controlled HOPE-HF trial assessed the benefit of atrio-ventricular (AV) delay optimization delivered using His bundle pacing. It recruited patients with left ventricular ejection fraction ≤40%, PR interval ≥200 ms, and baseline QRS ≤140 ms or right bundle branch block. Overall, there was no significant increase in peak oxygen uptake (VOmax) but there was significant improvement in heart failure specific quality of life.

RIPPLE-VT study: Multicenter prospective evaluation of ventricular tachycardia substrate ablation by targeting scar channels to eliminate latest scar potentials without direct ablation.

Background: Recurrent ventricular tachycardia (VT) can be treated by substrate modification of the myocardial scar by catheter ablation during sinus rhythm without VT induction. Better defining this arrhythmic substrate could help improve outcome and reduce ablation burden.

Objective: The study aimed to limit ablation within postinfarction scar to conduction channels within the scar to reduce VT recurrence.

Therapeutic potential of conduction system pacing as a method for improving cardiac output during ventricular tachycardia.

Background: Ventricular tachycardia (VT) reduces cardiac output through high heart rates, loss of atrioventricular synchrony, and loss of ventricular synchrony. We studied the contribution of each mechanism and explored the potential therapeutic utility of His bundle pacing to improve cardiac output during VT.

Methods: Study 1 aimed to improve the understanding of mechanisms of harm during VT (using pacing simulated VT).

Characterization of conduction system activation in the postinfarct ventricle using ripple mapping.

Background: Three-dimensional (3D) mapping of the ventricular conduction system is challenging.

Objective: The purpose of this study was to use ripple mapping to distinguish conduction system activation to that of adjacent myocardium in order to characterize the conduction system in the postinfarct left ventricle (LV).

Methods: High-density mapping (PentaRay, CARTO) was performed during normal rhythm in patients undergoing ventricular tachycardia ablation.

Machine learning-derived cycle length variability metrics predict spontaneously terminating ventricular tachycardia in implantable cardioverter defibrillator recipients.

Aims: Implantable cardioverter defibrillator (ICD) therapies have been associated with increased mortality and should be minimized when safe to do so. We hypothesized that machine learning-derived ventricular tachycardia (VT) cycle length (CL) variability metrics could be used to discriminate between sustained and spontaneously terminating VT.

Methods And Results: In this single-centre retrospective study, we analysed data from 69 VT episodes stored on ICDs from 27 patients (36 spontaneously terminating VT, 33 sustained VT).

An Economic Evaluation of a Streamlined Day-Case Atrial Fibrillation Ablation Protocol and Conventional Cryoballoon Ablation versus Antiarrhythmic Drugs in a UK Paroxysmal Atrial Fibrillation Population.

Background And Aims: Symptom control for atrial fibrillation can be achieved by catheter ablation or drug therapy. We assessed the cost effectiveness of a novel streamlined atrial fibrillation cryoballoon ablation protocol (AVATAR) compared with optimised antiarrhythmic drug (AAD) therapy and a conventional catheter ablation protocol, from a UK National Health Service (NHS) perspective.

Methods: Data from the AVATAR study were assessed to determine the cost effectiveness of the three protocols in a two-step process.

Catheter Ablation for Ventricular Tachycardia After MI: A Reconstructed Individual Patient Data Meta-analysis of Randomised Controlled Trials.

Background: The prognostic impact of ventricular tachycardia (VT) catheter ablation is an important outstanding research question. We undertook a reconstructed individual patient data meta-analysis of randomised controlled trials comparing ablation to medical therapy in patients developing VT after MI.

Methods: We systematically identified all trials comparing catheter ablation to medical therapy in patients with VT and prior MI.

Left atrial appendage occlusion for atrial fibrillation and bleeding diathesis.

Background: Patients with atrial fibrillation (AF) and likelihood of bleeding can undergo left atrial appendage occlusion (LAAO) as an alternative method of stroke prophylaxis. Short-term anti-thrombotic drugs are used postprocedure to offset the risk of device-related thrombus, evidence for this practice is limited.

Objectives: To investigate optimal postimplant antithrombotic strategy in high bleeding-risk patients.

RETRO-mapping: A novel algorithm automating wavefront categorization using activation mapping during persistent atrial fibrillation demonstrates a reduction in wavefront collisions following pulmonary vein isolation.

RETRO-mapping was developed to automate activation mapping of atrial fibrillation (AF). We used the algorithm to study the effect of pulmonary vein isolation (PVI) on the frequency of focal, planar, and colliding wavefronts in persistent AF. An AFocusII catheter was placed on the left atrial endocardium to record 3 s of AF at six sites pre and post-PVI in patients undergoing wide circumferential PVI for persistent AF.

Left bundle branch pacing with and without anodal capture: impact on ventricular activation pattern and acute haemodynamics.

Aims: Left bundle branch pacing (LBBP) can deliver physiological left ventricular activation, but typically at the cost of delayed right ventricular (RV) activation. Right ventricular activation can be advanced through anodal capture, but there is uncertainty regarding the mechanism by which this is achieved, and it is not known whether this produces haemodynamic benefit.

Methods And Results: We recruited patients with LBBP leads in whom anodal capture eliminated the terminal R-wave in lead V1.

Ripple AT Plus - isthmus-guided vs conventional ablation in the treatment of scar-related atrial tachycardia: study protocol for a randomised controlled trial.

Background: Catheter ablation is routinely used to treat scar-related atrial tachycardia (s-AT). Conventional ablation often involves creating anatomical "lines" that transect myocardial tissue supporting reentry. This can be extensive, creating iatrogenic scar as a nidus for future reentry, and may account for arrhythmia recurrence.

A randomized controlled trial to investigate the use of acute coronary syndrome therapy in patients hospitalized with COVID-19: the COVID-19 Acute Coronary Syndrome trial.

Background: Patients hospitalized with COVID-19 suffer thrombotic complications. Risk factors for poor outcomes are shared with coronary artery disease.

Objectives: To investigate the efficacy of an acute coronary syndrome regimen in patients hospitalized with COVID-19 and coronary disease risk factors.

Artificial intelligence-enabled electrocardiogram to distinguish atrioventricular re-entrant tachycardia from atrioventricular nodal re-entrant tachycardia.

Background: Accurately determining arrhythmia mechanism from a 12-lead electrocardiogram (ECG) of supraventricular tachycardia can be challenging. We hypothesized a convolutional neural network (CNN) can be trained to classify atrioventricular re-entrant tachycardia (AVRT) vs atrioventricular nodal re-entrant tachycardia (AVNRT) from the 12-lead ECG, when using findings from the invasive electrophysiology (EP) study as the gold standard.

Methods: We trained a CNN on data from 124 patients undergoing EP studies with a final diagnosis of AVRT or AVNRT.

Ventricular Conduction Stability Noninvasively Identifies an Arrhythmic Substrate in Survivors of Idiopathic Ventricular Fibrillation.

Background Idiopathic ventricular fibrillation (VF) is a diagnosis of exclusion following normal cardiac investigations. We sought to determine if exercise-induced changes in electrical substrate could distinguish patient groups with various ventricular arrhythmic pathophysiological conditions and identify patients susceptible to VF. Methods and Results Computed tomography and exercise testing in patients wearing a 252-electrode vest were combined to determine ventricular conduction stability between rest and peak exercise, as previously described.

Evaluation of RETRO-Mapping for electrophysiological features including direction of plane activity during atrial fibrillation using multipolar catheters in humans.

Introduction: A quantifiable, automated standard of analyzing heart rhythm has long eluded cardiologists due, in part, to the limitations in technology and the ability to analyze large electrogram datasets. In this proof-of-concept study, we propose new measures to quantify plane activity in atrial fibrillation (AF) using our Representation of Electrical Tracking of Origin (RETRO)-Mapping software.

Methods: We recorded 30 s segments of electrograms at the lower posterior wall of the left atrium using a 20-pole double loop catheter (AFocusII).

Feasibility of mapping and ablating ectopy-triggering ganglionated plexus reproducibly in persistent atrial fibrillation.

Background: Ablation of autonomic ectopy-triggering ganglionated plexuses (ET-GP) has been used to treat paroxysmal atrial fibrillation (AF). It is not known if ET-GP localisation is reproducible between different stimulators or whether ET-GP can be mapped and ablated in persistent AF. We tested the reproducibility of the left atrial ET-GP location using different high-frequency high-output stimulators in AF.

Artificial intelligence-enabled electrocardiogram to distinguish cavotricuspid isthmus dependence from other atrial tachycardia mechanisms.

Aims: Accurately determining atrial arrhythmia mechanisms from a 12-lead electrocardiogram (ECG) can be challenging. Given the high success rate of cavotricuspid isthmus (CTI) ablation, identification of CTI-dependent typical atrial flutter (AFL) is important for treatment decisions and procedure planning. We sought to train a convolutional neural network (CNN) to classify CTI-dependent AFL vs.