Contemporary Mapping Techniques of Complex Cardiac Arrhythmias - Identifying and Modifying the Arrhythmogenic Substrate.

Cardiac electrophysiology has moved a long way forward during recent decades in the comprehension and treatment of complex cardiac arrhythmias. Contemporary electroanatomical mapping systems, along with state-of-the-art technology in the manufacture of electrophysiology catheters and cardiac imaging modalities, have significantly enriched our armamentarium, enabling the implementation of various mapping strategies and techniques in electrophysiology procedures. Beyond conventional mapping strategies, ablation of complex fractionated electrograms and rotor ablation in atrial fibrillation ablation procedures, the identification and modification of the underlying arrhythmogenic substrate has emerged as a strategy that leads to improved outcomes.

The long-term effect of uranium and pH on the community composition of an artificial consortium.

In the environment, microorganisms are living in diverse communities, which are impacted by the prevailing environmental conditions. Here, we present a study investigating the effect of low pH and elevated uranium concentration on the dynamics of an artificial microbial consortium. The members (Caulobacter sp.

Percutaneous transapical access for pulmonary vein mapping and ablation in a porcine model with a new high-density electroanatomical mapping system.

Introduction: The porcine model is generally accepted for the development and testing of new forms oftherapy including ablation of atrial fibrillation (AF). However, the challenging left atrial (LA) and pulmonary vein (PV) anatomy enables only limited percutaneous catheter-based PV access.

Results: Here we present I) an alternative percutaneous transapical access, which enables easy and safe retrograde transmitral LA and PV mapping and ablation; II) early experience of LA mapping and successful circumferential PV isolation with novel mapping system (Rhythmia(TM)) and new generation of ablation catheter equipped with micro electrodes (IntellaTip MiFi).

Successful Repeat Catheter Ablation of Recurrent Longstanding Persistent Atrial Fibrillation With Rotor Elimination as the Procedural Endpoint: A Case Series.

Background: There remains a lack of consensus regarding the ideal ablation strategy for atrial fibrillation (AF), particularly in patients with persistent or longstanding persistent AF. Given increasing evidence from clinical imaging studies that rotors sustain AF, rotor elimination may be a desirable procedural endpoint. However, there is no description to date of the clinical outcomes using rotor elimination during ablation as the procedural endpoint.

Initial Experience With Ultra High-Density Mapping of Human Right Atria.

Introduction: Recently, an automatic, high-resolution mapping system has been presented to accurately and quickly identify right atrial geometry and activation patterns in animals, but human data are lacking. This study aims to assess the clinical feasibility and accuracy of high-density electroanatomical mapping of various RA arrhythmias.

Methods And Results: Electroanatomical maps of the RA (35 partial and 24 complete) were created in 23 patients using a novel mini-basket catheter with 64 electrodes and automatic electrogram annotation.

Pulmonary vein dilatation in a case of total pulmonary vein occlusion: Contemporary approach using a combination of 3D-mapping system and image integration.

Pulmonary vein stenosis (PVS) is a known complication of PV isolation procedures for atrial fibrillation. In this report a case of recurring PV occlusion after repeated percutaneous procedures has been described. Focus is on a novel interventional technique employing a three-dimensional mapping system which enables targeting total occlusion of PVs and on the use of a drug eluting balloon.

Electrical storm in patients with implantable cardioverter-defibrillator in the era of catheter ablation: Implications for better rhythm control.

Background: The modern era of cardiology has changed the population of implantable cardioverter-defibrillator (ICD) recipients. Identifying predictors of electrical storm (ES) in contemporary ICD patients could improve risk stratification, therapeutic strategies, and mortality.

Objective: The purpose of this study was to address these points in a real-world setting.

J wave pattern in unexplained syncope.

J wave pattern (JWP), characterized by J-point elevation in the anterolateral or inferior leads of the 12-lead electrocardiogram, has been associated with increased risk for idiopathic ventricular fibrillation and mortality. However, its prevalence in syncope of different etiologies is unknown and was evaluated in this study. The study sample comprised 170 consecutive patients with vasovagal syncope or syncope that remained unexplained after complete work-up.

Cardiogenic Stroke Despite Low CHA DS -VASc Score: Assessing Stroke risk by Left Atrial Appendage Anatomy (ASK LAA).

Introduction: In patients with atrial fibrillation (AF), LAA morphology has been suggested to modify thromboembolic event (TE) risk. We tested the hypothesis that TE in low-risk patients is associated with LAA characteristics.

Methods: Of 2,069 patients who underwent AF ablation, 25 (1.

Prospective, multicenter validation of a clinical risk score for left atrial arrhythmogenic substrate based on voltage analysis: DR-FLASH score.

Background: Left atrial (LA) low-voltage areas (LVAs) are frequently observed in patients with atrial fibrillation (AF) and may predict AF recurrence after catheter ablation.

Objective: The aim of this study was to develop and validate a clinical tool to identify LVAs that are associated with AF recurrence after pulmonary vein isolation (PVI).

Methods: In a cohort of 238 patients, voltage maps were created during LA procedures.

Non-fluoroscopic catheter tracking for fluoroscopy reduction in interventional electrophysiology.

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that the application of this non-fluoroscopic catheter visualization system (NFCV) reduces fluoroscopy time and dose by 90-95% in a variety of electrophysiology (EP) procedures. This can be of relevance not only to the patients, but also to the nurses and physicians working in the EP lab.

Differences in predictors of implantable cardioverter-defibrillator therapies in patients with ischaemic and non-ischaemic cardiomyopathies.

Aims: Implantable cardioverter-defibrillators (ICDs) have been shown to reduce mortality in patients with both ischaemic and non-ischaemic cardiomyopathy by terminating life-threatening arrhythmias. However, such arrhythmic events are unequally distributed among different patient subgroups. We aimed to evaluate predictors of appropriate ICD therapies as a step towards risk stratification in a real-world cohort.

Vernakalant-facilitated electrical cardioversion: comparison of intravenous vernakalant and amiodarone for drug-enhanced electrical cardioversion of atrial fibrillation after failed electrical cardioversion.

Aims: Electrical cardioversion is one cornerstone for the rhythm control strategy of atrial fibrillation (AF), which is, however, hampered by immediate AF recurrence (IRAF) or failed electrical cardioversion (FECV). We aimed to investigate the potential role of vernakalant for facilitated electrical cardioversion in cardioversion-resistant AF.

Methods And Results: The subjects of this study were 63 patients referred to the Heart Centre Leipzig between November 2011 and May 2014 for transthoracic electrical cardioversion of AF.

Freshwater Ammonia-Oxidizing Archaea Retain amoA mRNA and 16S rRNA during Ammonia Starvation.

In their natural habitats, microorganisms are often exposed to periods of starvation if their substrates for energy generation or other nutrients are limiting. Many microorganisms have developed strategies to adapt to fluctuating nutrients and long-term starvation. In the environment, ammonia oxidizers have to compete with many different organisms for ammonium and are often exposed to long periods of ammonium starvation.

Procedural Outcomes and Survival After Catheter Ablation of Ventricular Tachycardia in Relation to Electroanatomical Substrate in Patients With Nonischemic-Dilated Cardiomyopathy: The Role of Unipolar Voltage Mapping.

Introduction: In patients with ischemic cardiomyopathy the size of bipolar low-voltage areas (LVA) in electroanatomical maps (EAM) was associated with poorer outcomes after catheter ablation (CA) of ventricular tachycardia (VT). However, the effect of LVA size on the survival after VT ablation in patients with nonischemic dilated cardiomyopathy (NIDCM) has not been studied.

Methods And Results: In 55 patients with NIDCM (48 male, age 61 ± 16 years, ejection fraction 32 ± 13%) an EAM to delineate the bipolar and unipolar LVAs was performed in 52 (94.

Comparison of left atrial dimensions in CT and echocardiography as predictors of long-term success after catheter ablation of atrial fibrillation.

Purpose: Left atrium (LA) size is a common predictor of ablation outcomes in atrial fibrillation (AF), but different LA diameters have not been adequately studied yet. We aimed to find the best predictor of ablation outcomes using single-linear LA dimensions by computed tomography (CT) or echocardiography.

Methods: Patients (n = 103, 72 males, 59 ± 9 years) undergoing AF ablation were analyzed.

The APPLE score: a novel and simple score for the prediction of rhythm outcomes after catheter ablation of atrial fibrillation.

Background: Recurrent atrial fibrillation (AF) occurs in up to 50 % of patients within 1 year after catheter ablation, and a clinical risk score to predict recurrence remains a critical unmet need. The aim of this study was to (1) develop a simple score for the prediction of rhythm outcome following catheter ablation; (2) compare it with the CHADS2 and CHA2DS2-VASc scores, and (3) validate it in an external cohort.

Methods: Rhythm outcome between 3 and 12 months after AF catheter ablation were documented.

Galectin-3 in patients with atrial fibrillation undergoing radiofrequency catheter ablation.

Background: Galectin-3 (Gal-3) is an emerging biomarker in heart failure that is involved in fibrosis and inflammation. However, its potential value as a prognostic marker in atrial fibrillation (AF) is unknown. The aim of this study was to assess the impact of AF catheter ablation on Gal-3 and evaluate its prognostic impact for predicting rhythm outcome after catheter ablation.

Catheter ablation of ventricular tachycardia and mortality in patients with nonischemic dilated cardiomyopathy: can noninducibility after ablation be a predictor for reduced mortality?

Background: Data on outcomes after catheter ablation of ventricular tachycardia (VT) in patients with nonischemic dilated cardiomyopathy (NIDCM) are insufficient. We aimed to investigate the effects of successful catheter ablation of VT on cardiac mortality in patients with NIDCM.

Methods And Results: One hundred two patients with NIDCM (86 men; mean age, 58.

First Case of Automatic His Potential Detection With a Novel Ultra High-density Electroanatomical Mapping System for AV Nodal Ablation.

A 74-year old was considered for atrioventricular (AV) nodal ablation in view of atrial fibrillation (AF) with poorly controlled ventricular rate despite being on amiodarone. Targeted AV nodal ablation was successfully performed after identifying the target site for ablation by reviewing an ultra high-density map of the His region produced by automatic electrogram annotation.