Search results for "Intracardiac injection"
showing 10 items of 13 documents
The Fontan-Operation: From Intra- to Extracardiac Procedure
2003
Purpose For treatment of univentricular heart, the Fontan operation has been established as the definitive palliation. The current controversy is mainly based on the high incidence of arrhythmias after an intra-atrial lateral tunnel Fontan operation. Methods From January 1995 until April 2002. 46 children underwent a Fontan-type operation with or without a small fenestration. In 33 patients (group I) an Intracardiac tunnel and in 13 patients (group II) an extracardiac conduit procedure was performed. Principal findings There was no perioperative mortality. All patients showed postoperative a significant increase of arterial oxygen saturation, from 76 to 86% after surgery with fenestration, …
A Novel Approach to Propagation Pattern Analysis in Intracardiac Atrial Fibrillation Signals
2010
The purpose of this study is to investigate propagation patterns in intracardiac signals recorded during atrial fibrillation (AF) using an approach based on partial directed coherence (PDC), which evaluates directional coupling between multiple signals in the frequency domain. The PDC is evaluated at the dominant frequency of AF signals and tested for significance using a surrogate data procedure specifically designed to assess causality. For significantly coupled sites, the approach allows also to estimate the delay in propagation. The methods potential is illustrated with two simulation scenarios based on a detailed ionic model of the human atrial myocyte as well as with real data recordi…
P02.40: The influence of maternal age on the association of an isolated fetal intracardiac echogenic focus and fetal aneuploidy
2006
decided to follow up the pregnancy during two weeks and perform the cordocentesis in this time, karyotope was normal. At 26 weeks we found progressive changes in fetal anatomy: heart herniation became larger, left lobe of liver began to protruse, the absence of the sternum and cartilaginous parts of the ribs was confirmed. Patient was offered pregnancy termination because of the impossibility of surgical correction. Radiography, CT and morphology of abortus confirmed ultrasound diagnosis of isolated absence of the sternum and cartilaginous parts of the ribs.
An Automatic System for the Analysis and Classification of Human Atrial Fibrillation Patterns from Intracardiac Electrograms
2008
This paper presents an automatic system for the analysis and classification of atrial fibrillation (AF) patterns from bipolar intracardiac signals. The system is made up of: 1) a feature- extraction module that defines and extracts a set of measures potentially useful for characterizing AF types on the basis of their degree of organization; 2) a feature-selection module (based on the Jeffries-Matusita distance and a branch and bound search algorithm) identifying the best subset of features for discriminating different AF types; and 3) a support vector machine technique-based classification module that automatically discriminates the AF types according to the Wells' criteria. The automatic s…
Multicenter Consistency Assessment of Valvular Flow Quantification With Automated Valve Tracking in 4D Flow CMR
2021
OBJECTIVES This study determined: 1) the interobserver agreement; 2) valvular flow variation; and 3) which variables independently predicted the variation of valvular flow quantification from 4-dimensional (4D) flow cardiac magnetic resonance (CMR) with automated retrospective valve tracking at multiple sites. BACKGROUND Automated retrospective valve tracking in 4D flow CMR allows consistent assessment of valvular flow through all intracardiac valves. However, due to the variance of CMR scanners and protocols, it remains uncertain if the published consistency holds for other clinical centers. METHODS Seven sites each retrospectively or prospectively selected 20 subjects who underwent whole …
Intra-cardiac Signatures of Atrial Arrhythmias Identified by Machine Learning and Traditional Features
2021
Intracardiac devices separate atrial arrhythmias (AA) from sinus rhythm (SR) using electrogram (EGM) features such as rate, that are imperfect. We hypothesized that machine learning could improve this classification.
Flußquantifizierung von intrakardialen Shuntvolumina unter Verwendung der MR-Phasenkontrast-Technik in Atemanhaltephase
1998
PURPOSE Comparison of a breath-hold, velocity-encoded, phase-difference magnetic resonance (MR) sequence for intracardiac shunt flow measurement with the invasive shunt size determination by oximetry. PATIENTS AND METHODS 10 patients with different cardiac shunts (6 ASD/3 VSD/1 PDA) and four healthy individuals were investigated using a 1.5 Tesla Siemens Vision system. For flow measurements a breath-hold, velocity-encoded, phase-difference magnetic resonance (MR) sequence was used ('through plane', FLASH 2D-sequence, TR/TE 110/5 ms, 'velocity encoding' 250 cm/s). Mean flow (ml/R-R interval) in the ascending aorta, the pulmonary trunk, and the right and left pulmonary arteries was determined…
A Multi-Variate Predictability Framework to Assess Invasive Cardiac Activity and Interactions during Atrial Fibrillation
2017
Objective: This study introduces a predictability framework based on the concept of Granger causality (GC), in order to analyze the activity and interactions between different intracardiac sites during atrial fibrillation (AF). Methods: GC-based interactions were studied using a three-electrode analysis scheme with multi-variate autoregressive models of the involved preprocessed intracardiac signals. The method was evaluated in different scenarios covering simulations of complex atrial activity as well as endocardial signals acquired from patients. Results: The results illustrate the ability of the method to determine atrial rhythm complexity and to track and map propagation during AF. Conc…
Non-invasive Spatial Mapping of Frequencies in Atrial Fibrillation: Correlation With Contact Mapping
2021
[EN] Introduction: Regional differences in activation rates may contribute to the electrical substrates that maintain atrial fibrillation (AF), and estimating them non-invasively may help guide ablation or select anti-arrhythmic medications. We tested whether non-invasive assessment of regional AF rate accurately represents intracardiac recordings. Methods: In 47 patients with AF (27 persistent, age 63 +/- 13 years) we performed 57-lead non-invasive Electrocardiographic Imaging (ECGI) in AF, simultaneously with 64-pole intracardiac signals of both atria. ECGI was reconstructed by Tikhonov regularization. We constructed personalized 3D AF rate distribution maps by Dominant Frequency (DF) ana…
Intracardiac Cardioversion for Ablation of the Atrioventricular Conduction System in Patients with Drug Resistant Atrial Flutter
1983
The technique of intracardiac cardioversion for the ablation of the atrioventricular conduction system was used in three male patients (65, 53 and 57 years of age) with atrial flutter unresponsive to medical management. In the first patient a DC current of 80 J was applied while the other patients required 300 and 400 J respectively. In the first patient a transient third degree AVblock was induced enabling the ventricular rate to be easily controlled with drugs. This patient died 5 months later of resistant congestive heart failure. Autopsy revealed no gross evidence of myocardial damage in the tricuspid valve area or in the interventricular septum. In the other two patients a permanent th…