Is day-case surgical procedure safe for MICRA leadless pacemaker implantation?

Background: MICRA implantation is not commonly done as a day-case procedure. Elective leadless pacemakers are implanted routinely in our centre.

Objective: To assess whether the day-case MICRA procedure is safe.

Determinants of left atrial local impedance: Relationships with contact force, atrial fibrosis, and rhythm.

Introduction: The relationships between baseline tissue local impedance (LI), contact force (CF), atrial fibrosis, and atrial rhythm are uninvestigated in a clinical setting. We compared the relationship of LI and CF between atrial fibrillation (AF) and sinus rhythm (SR) accounting for the effects of atrial fibrosis as assessed by bipolar voltage and LI.

Methods: Patients undergoing persistent AF ablation were recruited.

Role of routine investigations post cardiac devices implants in detecting peri-procedural complications: A retrospective analysis from a tertiary UK center.

Background: Peri-procedural complications associated with cardiac implantable electronic devices are not uncommon. European Society of Cardiology guidelines recommend device checks of all devices within 72 h of implant. European Heart Rhythm Association expert practical guide on Cardiac implantable electronic devices (CIEDs) recommend that a chest x-ray (CXR) should be performed within 24 h to rule out pneumothorax and document lead positions.

Comparison of voltages between atria: differences in sinus rhythm and atrial fibrillation.

Background: Ultra high-density mapping systems allow for comparison of atrial electroanatomical maps in unprecedented detail. Atrial scar determined by voltages and surface area between atria, rhythm and atrial fibrillation (AF) types was assessed.

Methods: Left (LA) and right atrial (RA) maps were created using Rhythmia HDx in patients listed for ablation for paroxysmal (PAF, sinus rhythm (SR) maps only) or persistent AF (PeAF, AF and SR maps).

Broad and narrow complex tachycardia resulting in cardiorespiratory arrest in a child: what is the optimal treatment strategy?

Background: We describe a child with a broad and narrow complex tachycardia causing haemodynamic collapse.

Case Summary: A 9-year-old girl (weight 26 kg, height 114 cm) with a 5-year history of refractory 'epilepsy' presented with cardiorespiratory arrest and tonic-clonic seizure, witnessed by her mother. Electrocardiogram documented recurrent episodes of simultaneous broad and narrow tachycardias associated with haemodynamic compromise.

Leadless Pacemakers: Current Achievements and Future Perspectives.

Despite the technological advances in pacemaker technology, the transvenous implanted leads are still considered the Achilles' heel of this rhythm-control therapy. The leadless permanent pacemaker system was developed as an option to bypass the weakness of the transvenous approach. Advances in battery technology and deep miniaturisation of electronics now offer the opportunity to implant the whole pacemaker system into the right ventricle.

Preclinical cardiac perforation reduction in leadless pacing: An update to the Micra leadless pacemaker delivery system.

Background: Leadless pacemakers have been developed to avoid some of the complications that are associated transvenous pacemakers. Pericardial effusion is a rare complication of leadless pacemaker implantation, which may result from perforation of the delivery catheter. In this study, we describe preclinical perforation performance of an updated Micra delivery catheter.

A U.K. Multicenter Retrospective Study of the Learning Curve and Relative Impact on Success Rates and Procedural Metrics of the RHYTHMIA HDx™ Mapping System.

The learning curve for the novel RHYTHMIA HDx™ 3-dimensional electroanatomic system is unknown. Retrospective data collection was carried out at 3 U.K.

High-density electroanatomic activation mapping to guide slow pathway modification in patients with persistent left superior vena cava.

Background: Slow pathway (SP) mapping and modification can be challenging in patients with persistent left superior vena cava (PLSVC) due to anatomic variance of the Koch triangle (KT) and coronary sinus (CS) dilation. Studies using detailed 3-dimensional (3D) electroanatomic mapping (EAM) to investigate conduction characteristics and guide ablation targets in this condition are lacking.

Objectives: The purpose of this study was to describe a novel technique of SP mapping and ablation in sinus rhythm using 3D EAM in patients with PLSVC after validation in a cohort with normal CS anatomy.

Radiofrequency Ablation of the Diseased Human Left Ventricle: Biophysical and Electrogram-Based Analysis.

Background: Predictors of effective ablation lesion delivery in the human left ventricle are not established, particularly in scar. Impedance drop and electrogram (EGM) attenuation are potential surrogates to assess this.

Objectives: This study sought to establish the relationships between ablation index (AI) and force-time integral (FTI) with impedance drop and EGM attenuation in the human left ventricle.

Local Impedance Drop Predicts Durable Conduction Block in Patients With Paroxysmal Atrial Fibrillation.

Objectives: This analysis was performed to evaluate the transition of local impedance (LI) drop during pulmonary vein isolation (PVI) to durable block and mature lesion formation based on 3-month mapping procedures.

Background: A radiofrequency catheter measuring LI has been shown to be effective for performing PVI in patients with paroxysmal atrial fibrillation. Previous analysis has demonstrated LI drop to be predictive of pulmonary vein segment conduction block during an atrial fibrillation ablation procedure.

Targeted cluster ablation of non-CTI-dependent atrial arrhythmias in congenital heart disease using ultrahigh-definition mapping.

Background: Ablation of atrial arrhythmias in patients with congenital heart disease (CHD) has markedly improved with advanced mapping systems. However, recurrence rates remain high. The linear ablation strategy is not uncommonly practiced necessitating prolonged ablation times.

Rationale and study design of the MINERVA study: Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction-UK multicentre collaboration.

Introduction: The purpose of this study is to assess the ability of two new ECG markers (Regional Repolarisation Instability Index (R2I2) and Peak Electrical Restitution Slope) to predict sudden cardiac death (SCD) or ventricular arrhythmia (VA) events in patients with ischaemic cardiomyopathy undergoing implantation of an implantable cardioverter defibrillator for primary prevention indication.

Methods And Analysis: Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction is a prospective, open label, single blinded, multicentre observational study to establish the efficacy of two ECG biomarkers in predicting VA risk. 440 participants with ischaemic cardiomyopathy undergoing routine first time implantable cardioverter-defibrillator (ICD) implantation for primary prevention indication are currently being recruited.

Outcomes From Pediatric Ablation: A Review of 20 Years of National Data.

Objectives: This study set out to examine outcomes from pediatric supraventricular tachycardia ablations over a 20-year period. This study sought to examine success rates and repeat ablations over time and to evaluate whether modalities such as 3-dimensional (3D) mapping, contact force, and cryotherapy have improved outcomes.

Background: Ablation of supraventricular tachycardia in pediatric patients is commonly performed in most congenital heart centers with excellent long-term results.

Local catheter impedance drop during pulmonary vein isolation predicts acute conduction block in patients with paroxysmal atrial fibrillation: initial results of the LOCALIZE clinical trial.

Aims: Radiofrequency ablation creates irreversible cardiac damage through resistive heating and this temperature change results in a generator impedance drop. Evaluation of a novel local impedance (LI) technology measured exclusively at the tip of the ablation catheter found that larger LI drops were indicative of more effective lesion formation. We aimed to evaluate whether LI drop is associated with conduction block in patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein isolation (PVI).

Clinical outcomes and programming strategies of implantable cardioverter-defibrillator devices in paediatric hypertrophic cardiomyopathy: a UK National Cohort Study.

Aims: Sudden cardiac death (SCD) is the most common mode of death in paediatric hypertrophic cardiomyopathy (HCM). This study describes the implant and programming strategies with clinical outcomes following implantable cardioverter-defibrillator (ICD) insertion in a well-characterized national paediatric HCM cohort.

Methods And Results: Data from 90 patients undergoing ICD insertion at a median age 13 (±3.

Impact of different selection policies on subcutaneous ICD implants and therapies.

Background: Patients with existing or anticipated indications for cardiac resynchronisation therapy (CRT), bradycardia, or anti-tachycardia pacing should not be offered subcutaneous defibrillators (SQIDs) but it remains unclear how clinicians should predict future need for these therapies.

Methods: We applied three SQID selection policies to data collected retrospectively from transvenous implantable cardioverter defibrillator (TV-ICD) implants: (a) approach A, SQID used in inherited channelopathies and idiopathic ventricular fibrillation only; (b) approach B, as above, plus all hypertrophic cardiomyopathy and grown-up congenital heart disease patients; (c) approach C, as above, plus primary and secondary prevention (for ventricular fibrillation only) of SCD in patients with QRS <150 ms. Approach C reflects current ESC and AHA/ACC/HRS guidelines.

Machine learning detection of Atrial Fibrillation using wearable technology.

Background: Atrial Fibrillation is the most common arrhythmia worldwide with a global age adjusted prevalence of 0.5% in 2010. Anticoagulation treatment using warfarin or direct oral anticoagulants is effective in reducing the risk of AF-related stroke by approximately two-thirds and can provide a 10% reduction in overall mortality.

Ultra-High-Density Activation Mapping to Aid Isthmus Identification of Atrial Tachycardias in Congenital Heart Disease.

Objectives: A new electroanatomic mapping system (Rhythmia, Boston Scientific, Marlborough, Massachusetts) using a 64-electrode mapping basket is now available; we systematically assessed its use in complex congenital heart disease (CHD).

Background: The incidence of atrial arrhythmias post-surgery for CHD is high. Catheter ablation has emerged as an effective treatment, but is hampered by limitations in the mapping system's ability to accurately define the tachycardia circuit.

Screening for Atrial Fibrillation Using Economical and Accurate Technology (From the SAFETY Study).

The prevalence of atrial fibrillation (AF) is estimated at more than 3% in the adult population and there has been increased interest in screening for AF. In the SAFETY trial we chose to evaluate if inexpensive, wearable, consumer electrocardiography (ECG) sensing devices (Polar-H7 [PH7] and Firstbeat Bodyguard 2 [BG2]), could be used to detect AF accurately. We undertook a case-control study of 418 participants aged >65 (82 with AF and/or flutter at the study visit and 336 without) attending 3 general practice surgeries in Hampshire, UK for a single screening visit.