The Misleading QRS Morphology of Scar-Related Ventricular Tachycardia.

Background: The QRS morphology of ventricular tachycardia (VT) reflects the re-entry circuit exit location and helps guide mapping for radiofrequency ablation (RFA). It can be misleading, however, particularly in structural heart disease.

Objective: The aim of this study was to assess the relation of the site where RFA terminated VT to the location of the exit predicted by the VT QRS morphology.

Combined TAVR and Ventricular Tachycardia Ablation for VT Storm With Severe Aortic Stenosis.

Objective: To describe the feasibility and clinical considerations of a simultaneous transcatheter aortic valve replacement (TAVR) and ventricular tachycardia (VT) ablation in a critically ill patient with severe aortic stenosis and VT storm.

Key Steps: Preprocedural planning involved both electrophysiology and structural teams present. Transfemoral TAVR was performed using a Sapien S3 valve (Edwards Lifesciences) under general anesthesia with both transesophageal and transthoracic echocardiography guidance.

Clinical Presentation and Long-Term Outcomes of Late-Onset Symptomatic ARVC.

Background: Diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) is often made after arrhythmias are detected in the second or third decade but can also present later.

Objectives: The authors sought to compare the phenotypes and the long-term outcome between patients with early- vs late-onset ARVC.

Methods: Patients with a definite ARVC diagnosis fulfilling the 2010 Task Force criteria and symptomatic arrhythmias at initial presentation were candidates.

Clinical Outcomes of Concurrent Ventricular Electrical Storm and Infection.

Background: Electrical storm (ES) is a cluster of sustained ventricular arrhythmias that may be caused by various triggers on the arrhythmic substrate. The association between infection and ES is unknown.

Objectives: This study sought to investigate the clinical profile and prognosis of concurrent ES and infection.

Fascicular and Papillary Muscle Arrhythmias in the Structurally Normal Heart.

Arrhythmias originating from the specialised cardiac conduction system and papillary muscles can occur in both structurally normal and diseased hearts. Conduction system associated arrhythmias include bundle branch re-entry, fascicular re-entry, non-re-entrant fascicular ventricular tachycardia and idiopathic ventricular fibrillation. Each type of arrhythmia requires a unique diagnostic and therapeutic approach.

Performance of cardiac implantable electronic devices in detecting premature ventricular contraction burden.

Background: Frequent premature ventricular contractions (PVCs) can cause or exacerbate cardiomyopathy. At-risk patients often have cardiac implantable electronic devices (CIEDs) for treating bradycardia or ventricular arrhythmias. Many modern CIEDs also collect objective data about arrhythmias, including PVCs.

The Therapeutic Impact of Genetic Evaluation in an Atrial Fibrillation Precision Medicine Clinic.

Background And Aims: Genetic testing is recommended for select patients with atrial fibrillation (AF). The aims of this study were to define the results of genetic evaluation and its therapeutic impact for patients referred to a dedicated AF precision medicine clinic.

Methods: Patients diagnosed with AF before age 60 were candidates for referral.

Sensing and detection performance of the novel, small-diameter OmniaSecure defibrillation lead: in-depth analysis from the LEADR trial.

Aims: The Lead EvaluAtion for Defibrillation and Reliability (LEADR) trial evaluated the small-diameter (4.7 Fr), integrated bipolar OmniaSecure defibrillation lead. As previously reported, the trial exceeded primary safety and efficacy objective thresholds, demonstrating favourable performance and zero fractures through ∼12 months follow-up, with patients in ongoing follow-up.

Mechanisms of ventricular tachycardias with a 1:1 His-V relation in patients with heart disease.

Background: Ventricular tachycardia (VT) with a 1:1 V-His relation can be seen in bundle branch reentry or with passive retrograde activation from scar-related VT or reentry using left ventricular Purkinje fascicles.

Objective: This study aimed to review the frequency with which 1:1 V-His relation occurs and to identify differentiating characteristics of these arrhythmias, including new measures obtained during right ventricular (RV) pacing based on orthodromic His-proximal right bundle potential (HisRB) capture and the stimulus to HisRB (S-HisRB) interval approximating RV electrogram to His interval (Egm-HisRB).

Methods: This was a retrospective review of induced VTs that had a HisRB potential recorded while pacing from the distal right ventricle.

Outcome of repeat ablation for premature ventricular contractions in patients with prior ablation failure: Impact of advanced techniques.

Background: The utility of repeat ablation for premature ventricular contractions (PVCs) after prior ablation failure is not clear.

Objective: The purpose of this study was to assess the outcomes of repeat ablation and the use of different techniques in patients who failed prior PVC ablation.

Methods: We reviewed 239 consecutive patients who underwent PVC ablation.

State of the Art: Mapping Strategies to Guide Ablation in Ischemic Heart Disease.

Catheter ablation to prevent ventricular tachycardia (VT) that emerges late after a myocardial infarction aims to interrupt the re-entry substrate. Interruption of potential channels and regions of slow conduction that can be identified during stable sinus or paced rhythm is often effective and a number of substrate markers for guiding this approach have been described. While there is substantial agreement with different markers in some patients, the different markers select different regions for ablation in others.

Emergent Ablation for Ventricular Tachycardia: Predictors of Prolonged Hospitalization and Mortality.

Background: Patients with ventricular tachycardia (VT) frequently present in unstable VT and are subject to urgent/high-risk ablation procedures. Clinical predictors of prolonged hospitalization and mortality are needed for optimal management of these patients.

Objectives: This study seeks to identify factors associated with prolonged hospitalization and mortality in emergent unplanned VT ablation procedures.

Can Intracardiac Echocardiography Reduce Steam Pops During Half-Normal Saline Irrigated Radiofrequency Ablation?

Background: Irrigated radiofrequency ablation with half-normal saline can potentially increase lesion size but may increase the risk of steam pops with the risk of emboli or perforation. We hypothesized that pops would be preceded by intracardiac echocardiography (ICE) findings as well as a large impedance fall.

Methods: In 100 consecutive patients undergoing endocardial ventricular arrhythmia radiofrequency ablation with half-normal saline, we attempted to observe the ablation site with ICE.

Intramural needle ablation or repeated standard ablation in patients referred for repeat ablation of scar-related ventricular tachycardia.

Introduction: When ventricular tachycardia (VT) recurs after standard RF ablation (sRFA) some patients benefit from repeat sRFA, whereas others warrant advanced methods such as intramural needle ablation (INA). Our objectives are to assess the utility of repeat sRFA and to clarify the benefit of INA when repeat sRFA fails in patients with VT due to structural heart disease.

Methods: In consecutive patients who were prospectively enrolled in a study for INA for recurrent sustained monomorphic VT despite sRFA, repeat sRFA was considered first.

Recurrence After Atrial Fibrillation Ablation and Investigational Biomarkers of Cardiac Remodeling.

Background: Recurrence after atrial fibrillation (AF) ablation remains common. We evaluated the association between recurrence and levels of biomarkers of cardiac remodeling, and their ability to improve recurrence prediction when added to a clinical prediction model.

Methods And Results: Blood samples collected before de novo catheter ablation were analyzed.

Safety of ventricular arrhythmia radiofrequency ablation with half-normal saline irrigation.

Aims: Failure of radiofrequency (RF) ablation of ventricular arrhythmias is often due to inadequate lesion size. Irrigated RF ablation with half-normal saline (HNS) has the potential to increase lesion size and reduce sodium delivery to the patient if the same volume of RF irrigant were used for normal saline (NS) and HNS but could increase risks related to steam pops and lesion size. This study aims to assess periprocedural complications and acute ablation outcome of ventricular arrhythmias ablation with HNS.