Different Ventricular Fibrillation Types in Low-Dimensional Latent Spaces.

The causes of ventricular fibrillation (VF) are not yet elucidated, and it has been proposed that different mechanisms might exist. Moreover, conventional analysis methods do not seem to provide time or frequency domain features that allow for recognition of different VF patterns in electrode-recorded biopotentials. The present work aims to determine whether low-dimensional latent spaces could exhibit discriminative features for different mechanisms or conditions during VF episodes.

Catheter ablation of ventricular arrhythmias in left ventricular noncompaction cardiomyopathy.

Background: There are limited data on ventricular arrhythmias (VAs) associated with left ventricular noncompaction (LVNC) cardiomyopathy.

Objectives: This study aims to analyze the clinical and electrocardiographic characteristics of VAs in a group of patients with LVNC.

Methods: Forty-two nonrelated patients with LVNC and VAs were included that were evaluated at the Inherited Cardiac Disease Unit of the University Hospital Virgen Arrixaca (Murcia-Spain) (ERN Guard-Heart Centre, European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart).

Spectral Analysis and Mutual Information Estimation of Left and Right Intracardiac Electrograms during Ventricular Fibrillation.

Ventricular fibrillation (VF) signals are characterized by highly volatile and erratic electrical impulses, the analysis of which is difficult given the complex behavior of the heart rhythms in the left (LV) and right ventricles (RV), as sometimes shown in intracardiac recorded Electrograms (EGM). However, there are few studies that analyze VF in humans according to the simultaneous behavior of heart signals in the two ventricles. The objective of this work was to perform a spectral and a non-linear analysis of the recordings of 22 patients with Congestive Heart Failure (CHF) and clinical indication for a cardiac resynchronization device, simultaneously obtained in LV and RV during induced VF in patients with a Biventricular Implantable Cardioverter Defibrillator (BICD) Contak Renewal IV (Boston Sci.

[Psychological adjustment in patients with an implantable cardioverter defibrillator: primary prevention and secondary prevention. A comparative study.].

Objective: The implantation of the Implantable Cardioverter Defibrillator (ICD) influences the psychological adjustment and the degree of subjective discomfort. The objective of this work was to analyze differences in psychological adjustment, fear of shocks and the degree of subjective discomfort derived from the illness depending on the reasons for implantation (primary vs secondary).

Methods: A sample of 82 patients with an ICD, for primary (58.

Emergency department attendance and reasons for consultation after cryoballoon ablation for pulmonary vein isolation of atrial fibrillation.

Introduction And Objectives: There are few data on emergency visits after cryoballoon-based pulmonary vein isolation. The aim of this study was to quantify emergency department visits during the first 3 months after the procedure and to identify the reasons for consultation, final diagnoses, and the therapeutic approach.

Methods: Observational, retrospective study of 330 consecutive patients undergoing a first cryoballoon-based ablation procedure.

Medium- and long-term outcome after a single second-generation cryoballoon ablation in patients with paroxysmal and persistent atrial fibrillation.

Introduction And Objectives: To report medium- and long-term results following a single second-generation cryoballoon (CB2)-based ablation procedure in patients with paroxysmal (PAF) and persistent (PeAF) atrial fibrillation.

Methods: A retrospective study was performed of consecutive patients undergoing a first CB2-based ablation procedure in a tertiary center. Cryoenergy was applied for 3 min if a time to effect <60 s was documented or 4 min otherwise, with a bonus application in cases of late isolation or suboptimal temperature.

Force Trends and Pulsatility for Catheter Contact Identification in Intracardiac Electrograms during Arrhythmia Ablation.

The intracardiac electrical activation maps are commonly used as a guide in the ablation of cardiac arrhythmias. The use of catheters with force sensors has been proposed in order to know if the electrode is in contact with the tissue during the registration of intracardiac electrograms (EGM). Although threshold criteria on force signals are often used to determine the catheter contact, this may be a limited criterion due to the complexity of the heart dynamics and cardiac vorticity.

Value of the "Standing Test" in the Diagnosis and Evaluation of Beta-blocker Therapy Response in Long QT Syndrome.

Introduction And Objectives: Patients with congenital long QT syndrome (LQTS) have an abnormal QT adaptation to sudden changes in heart rate provoked by standing. The present study sought to evaluate the standing test in a cohort of LQTS patients and to assess if this QT maladaptation phenomenon is ameliorated by beta-blocker therapy.

Methods: Electrographic assessments were performed at baseline and immediately after standing in 36 LQTS patients (6 LQT1 [17%], 20 LQT2 [56%], 3 LQT7 [8%], 7 unidentified-genotype patients [19%]) and 41 controls.

Diagnostic Approach to Unexplained Cardiac Arrest (from the FIVI-Gen Study).

Unexplained cardiac arrest (UCA) can be caused by low-penetrance genetic disorders. The aim of this cross-sectional study is to assess the usefulness of a new diagnostic protocol: Thirty-five patients were recruited from 9 Spanish centers. Electrocardiogram, echocardiogram, and coronary catheterization were used to rule out electrical or structural heart disease in all subjects.

Heterogeneous Phenotype of Long QT Syndrome Caused by the KCNH2-H562R Mutation: Importance of Familial Genetic Testing.

Introduction And Objectives: Long QT syndrome is an inherited ion channelopathy that leads to syncope and sudden death. Because of the heterogeneous phenotype of this disease, genetic testing is fundamental to detect individuals with concealed long QT syndrome. In this study, we determined the features of a family with 13 carriers of the KCNH2-H562R missense mutation, which affects the pore region of the HERG channel.

Genetics of myocarditis in arrhythmogenic right ventricular dysplasia.

Background: Myocarditis occasionally is related to arrhythmogenic right ventricular dysplasia (ARVD) and sometimes overlaps during the early stages, which may lead to misdiagnosis. Acute myocarditis may reflect an active phase of ARVD.

Objective: The purpose of this study was to evaluate the genetic basis of myocarditis in ARVD and to investigate the association with a poorer prognosis and a higher risk of ventricular arrhythmias.

Desmoplakin truncations and arrhythmogenic left ventricular cardiomyopathy: characterizing a phenotype.

Aims: Risk stratification for sudden death in arrhythmogenic right ventricular cardiomyopathy (ARVC) is challenging in clinical practice. We lack recommendations for the risk stratification of exclusive left-sided phenotypes. The aim of this study was to investigate genotype-phenotype correlations in patients carrying a novel DSP c.

[Phrenic nerve identification with cardiac multidetector computed tomography].

Cryoballoon ablation of the pulmonary veins is a new technique that has proven useful in preventing paroxysmal and persistent atrial fibrillation recurrence. One of the most serious complications of this method is right phrenic nerve palsy. The usefulness of multidetector computed tomography to locate the right phrenic nerve and artery and predict the risk of phrenic nerve palsy during cryoablation according to the distance between the right phrenic neurovascular bundle and the right superior pulmonary vein ostium has recently been described.

Ablation of Premature Ventricular Complexes Triggering Ventricular Fibrillation in a Patient with Long QT Syndrome.

We describe the case of a patient with long QT syndrome and recurrent ventricular fibrillation, triggered by premature ventricular complexes (PVCs) with a left bundle branch block pattern and inferior axis of the QRS. Activation mapping demonstrated the origin of the PVCs to be in the right ventricular outflow tract. Ventricular fibrillation (VF) was successfully treated by catheter ablation of the triggering PVCs and there has been no recurrence of VF during a follow-up period of 14 months.

Multiple interatrial electrical connection after heart transplantation.

A 62-year-old woman who underwent heart transplantation 6 years later presented a regular atrial tachycardia. Electrophysiologic evaluation showed an atrial arrhythmia in the recipient atrium with 2:1 conduction to the donor atrium, with a confusing electroanatomical map. With the suspect of alternant conduction through two different breakthroughs, the map was split in two concordant maps, corresponding to two connections that were successfully ablated.

Premature ventricular complexes as a trigger for ventricular fibrillation.

Introduction And Objectives: The mechanisms that trigger ventricular fibrillation (VF) are poorly understood. The aim of this study was to analyze the initiation of VF in electrograms stored in implantable cardioverter-defibrillators (ICDs).

Methods: We analyzed ICD electrograms from patients who had suffered at least one episode of VF.

Fundamental frequency and regularity of cardiac electrograms with Fourier organization analysis.

Dominant frequency analysis (DFA) and organization analysis (OA) of cardiac electrograms (EGMs) aims to establish clinical targets for cardiac arrhythmia ablation. However, these previous spectral descriptions of the EGM have often discarded relevant information in the spectrum, such as the harmonic structure or the spectral envelope. We propose a fully automated algorithm for estimating the spectral features in EGM recordings.

Same morphology of ventricular premature complexes triggering repeated ventricular fibrillation.

Background: Episodes ventricular fibrillation (VF) initiated by ventricular premature complexes (VPCs) of a single morphology have been reported. However, the characteristics of the VPCs over long periods of time are unknown.

Objectives: To compare the morphologies and coupling intervals of VPCs that initiate episodes of VF that occur at different time periods.

ICD proarrhythmia as a consequence of an interaction with an algorithm to prevent atrial arrhythmias.

An episode of device-related proarrhythmia is reported. Ventricular tachycardia was induced by ventricular pacing in a dual-chamber implantable cardioverter-defibrillator due to an inappropriate interaction of programmed device settings with the atrial preference pacing, an automatic algorithm designed to prevent atrial tachyarrhythmias.

Spectral analysis of sustained and non-sustained ventricular fibrillation in patients with an implantable cardioverter-defibrillator.

The mechanisms responsible for the maintenance and termination of ventricular fibrillation (VF) are poorly understood. The aim of this study was to compare the spectral characteristics of the electrical signal during sustained and non-sustained VF in patients with an implantable cardioverter-defibrillator. The study included 51 patients who had had at least one episode of sustained VF (i.

Spectral analysis of intracardiac electrograms during induced and spontaneous ventricular fibrillation in humans.

Aims: Very limited data are available on the differences between spontaneous and induced episodes of ventricular fibrillation (VF) in humans. The aim of the study was to compare the spectral characteristics of the electrical signal recorded by an implantable cardioverter defibrillator (ICD) during both types of episodes.

Methods And Results: Thirteen ICD patients with at least one spontaneous and one induced VF recorded by the device were included in the study.

Effects of the location of myocardial infarction on the spectral characteristics of ventricular fibrillation.

Background: The location of the myocardial infarction (MI) might modify the spectral characteristics of ventricular fibrillation (VF) in humans.

Objective: To evaluate the effect of the location of the infarcted area on the spectral parameters of VF.

Methods: Patients with chronic MI (29 anterior, 32 inferior) and induced VF during cardioverter defibrillator implant were retrospectively studied.