Delineation of intracavitary electrograms for the automatic quantification of decrement-evoked potentials in the coronary sinus with deep-learning techniques.

Cardiac arrhythmias cause depolarization waves to conduct unevenly on the myocardial surface, potentially delaying local components with respect to a previous beat when stimulated at faster frequencies. Despite the diagnostic value of localizing the distinct local electrocardiogram (EGM) components for identifying regions with decrement-evoked potentials (DEEPs), current software solutions do not perform automatic signal quantification. Electrophysiologists must manually measure distances on the EGM signals to assess the existence of DEEPs during pacing or extra-stimuli protocols.

Automated isochronal late activation mapping for substrate characterization in patients with repaired tetralogy of Fallot.

Aims: Slow conduction (SC) anatomical isthmuses (AIs) are the dominant substrate for monomorphic ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (rTF). This study aimed to evaluate the utility of automated propagational analysis for the identification of SC-AI in patients with rTF.

Methods And Results: Consecutive rTF patients undergoing VT substrate characterization were included.

Brugada syndrome masked by complete left bundle branch block: A clinical and functional study of its association with the p.1449Y>H SCN5A variant.

SCN5A gene variants are associated with both Brugada syndrome and conduction disturbances, sometimes expressing an overlapping phenotype. Functional consequences of SCN5A variants assessed by patch-clamp electrophysiology are particularly beneficial for correct pathogenic classification and are related to disease penetrance and severity. Here, we identify a novel SCN5A loss of function variant, p.

Long-Term Survival After Implantable Cardiac Defibrillator Therapy According to Sex: A Propensity Matched Study.

Whether the sex factor influences the benefit of the implantable cardioverter-defibrillator (ICD) for the prevention of sudden death remains a subject of debate. Using a prospective registry, we sought to analyze the survival and time to first ICD therapy according to sex. Retrospective analysis of a prospective cohort of patients undergoing an ICD implant from 2008 to 2019.

Long-term outcomes of ventricular tachycardia substrate ablation incorporating hidden slow conduction analysis.

Background: Ventricular tachycardia substrate ablation (VTSA) incorporating hidden slow conduction (HSC) analysis allows further arrhythmic substrate identification.

Objective: The purpose of this study was to analyze whether the elimination of HSC electrograms (HSC-EGMs) during VTSA results in better short- and long-term outcomes.

Methods: Consecutive patients (N = 70; 63% ischemic; mean age 64 ± 14.

Dramatic reduction of ventricular tachycardia burden after dronedarone plus mexiletine treatment in a patient refractory to hybrid ablation.

Antiarrhythmic drugs are often the last resort for recurrent ventricular tachycardia refractory to catheter ablation in implantable cardioverter-defibrillator carriers. Amiodarone, alone or combined with mexiletine, is usually but not always highly effective, and its use is usually limited by systemic adverse effects. We present the case of a 62 years old man with recurrent ICD shocks due to a VT refractory to an endo-epicardial hybrid ablation.

Analysis of late reconnections after pulmonary vein isolation: Impact of interlesion contiguity and ablation index.

Background: Interlesion distance and ablation index (AI) have been proposed as parameters of radiofrequency (RF) lesion durability. This study analyzes the relationship between RF parameters of automatically acquired lesion tags and late reconnections in repeat pulmonary vein isolation (PVI) procedures.

Methods: One hundred fifty-seven patients underwent contact force (CF)-guided PVI with automatic acquisition of RF lesions.

Clinical validation of automatic local activation time annotation during focal premature ventricular complex ablation procedures.

Aims: Current navigation systems incorporate algorithms for automatic identification of local activation time (LAT). However, data about their utility and accuracy in premature ventricular complex (PVC) ablation procedures are scarce. This study analyses the accuracy of an algorithmic method based on automatic annotation of the maximal negative slope of the unipolar electrogram within the window demarcated by the bipolar electrogram compared with conventional manual annotation during PVC ablation procedures.

Repeated procedures at the generator pocket are a determinant of implantable cardioverter-defibrillator infection.

Background: Rates of cardiac-device infections have increased in recent years, but the current incidence and risk factors for infection in patients with implantable cardioverter-defibrillators (ICDs) are not well known.

Hypothesis: The increasing number of ICD infections is related to accumulated pocket manipulations over time.

Methods: This single-center, prospective study included patients that underwent ICD implantation from 2008 to 2015.

Paroxysmal atrial fibrillation ablation: Achieving permanent pulmonary vein isolation by point-by-point radiofrequency lesions.

Pulmonary vein isolation by point-by-point radiofrequency catheter ablation constitutes the cornerstone of catheter ablation strategies for the treatment of atrial fibrillation. However, despite advances in pulmonary vein isolation ablation strategies, long-term success rates after ablation remain suboptimal, which highlights the need to develop techniques to achieve more durable lesions. Strategies proposed to improve the durability of pulmonary vein isolation can be divided into two groups: Those addressed to improving the quality of the lesion and those that optimize the detection of acute PV reconnection during the ablation procedure.

Impact of Contact Force Monitoring in Acute Pulmonary Vein Isolation Using an Anatomic Approach. A Randomized Study.

Background: The impact of contact force (CF) monitoring in pulmonary vein (PV) isolation after a circumferential anatomic ablation (CAA) is unknown. We analyze the usefulness of CF monitoring in acute PV isolation and procedure parameters using a CAA.

Methods: Fifty patients with paroxysmal atrial fibrillation were randomized into CF-on (CF >10 grams; n = 25) or CF-off (CF blinded; n = 25) groups.

Reverse atrial remodeling following pulmonary vein isolation: the importance of the body mass index.

Background: Pulmonary vein isolation (PVI) causes a reduction in left atrium size that is attributable to reverse atrial remodeling (RAR). The objective of this study was to identify predictors of RAR and determine its association with other parameters of improvement in cardiac function.

Methods: It is a prospective study with 74 patients (52 ± 9 years old, 81% male), and 51% of patients had paroxysmal atrial fibrillation.

Paroxysmal atrial fibrillation burden before and after pulmonary veins isolation: an observational study through a subcutaneous leadless cardiac monitor.

Aims: Data on the success rate of ablation in atrial fibrillation (AF) are controversial. Our hypothesis is that the efficacy must be evaluated considering the AF burden (AFB) before the procedure. Moreover, the clinical significance of early recurrence (ERAT) of AF or atrial tachyarrhythmias (AT) is debatable.

Ablation of atrioventricular nodal reentrant tachycardia in a patient with tricuspid atresia guided by electroanatomic mapping.

We describe a case of ablation of atrioventricular nodal reentrant tachycardia in a patient with tricuspid atresia and L-malposition of great vessels using an electroanatomical mapping system integrated with cardiac magnetic resonance imaging. Atrial activation mapping during tachycardia identified the retrograde fast pathway proximal to the His bundle, observed in the left interatrial septum. Ablation was successfully completed below this area.

Electroanatomical mapping of the esophagus in circumferential pulmonary vein isolation.

A virtual reconstruction of the geometry of the esophagus was produced using an electroanatomical mapping system and a specially designed catheter in 20 consecutive patients undergoing circumferential pulmonary vein isolation. The course of the esophagus, its motion and its proximity to the predicted lines of application of radiofrequency energy to the left atrium were evaluated. Thirteen (65%) were located centrally (i.

Unusual tachycardia association in a patient without structural heart disease.

We report an unusual association of persistent atrial flutter and bundle branch re-entrant ventricular tachycardia in a young patient without structural heart disease. Atrial flutter masked the infra-Hisian conduction disease, was fundamentally dependent on a long PR interval, and could be a possible trigger of ventricular tachycardia.

Three-dimensional impedance mapping as an aid to circumferential pulmonary vein isolation in paroxysmal atrial fibrillation.

During circumferential pulmonary vein isolation, radiofrequency lesions are created in the transition zone between the left atrium and the pulmonary veins, outside the ostia, to avoid stenosis. Three-dimensional impedance maps were constructed for 25 patients with paroxysmal atrial fibrillation. In the first 15 patients, impedance was measured inside the pulmonary veins (165.