Search results for "Electrophysiologic Techniques"
showing 10 items of 16 documents
Measurement of the local aortic stiffness by a non-invasive bioelectrical impedance technique.
2011
International audience; Aortic stiffness measurement is well recognized as an independent predictor of cardiovascular mortality and morbidity. Recently, a simple method has been proposed for the evaluation of the local aortic stiffness (AoStiff) using a non-invasive bioelectrical impedance (BI) technique. This approach relies on a novel interpretation of the arterial stiffness where AoStiff is computed from the measurement of two new BI variables: (1) the local aortic flow resistance (AoRes) exerted by the drag forces onto the flow; (2) the local aortic wall distensibility (AoDist). Herein, we propose to detail and compare these three indices with the reference pulse wave velocity (PWV) mea…
Wave similarity mapping shows the spatiotemporal distribution of fibrillatory wave complexity in the human right atrium during paroxysmal and chronic…
2005
Introduction: The complexity of waveforms during atrial fibrillation may reflect critical activation patterns for the arrhythmia perpetuation. In this study, we introduce a novel concept of map, based on the analysis of the wave morphology, which gives a direct evidence in the human right atrium on the spatiotemporal distribution of fibrillatory wave complexity in paroxysmal (PAF) and chronic (CAF) atrial fibrillation. Methods and Results: Electrograms were recorded from a 64-electrode catheter in the right atrium of 15 patients during PAF (n = 8) and CAF (n = 7). Wave similarity maps were constructed by calculating the degree of morphological similarity of activation waves (S) at each atri…
Cardiac arrhythmias in patients with Danon disease.
2016
Aims Different cardiac arrhythmias have been suggested to be associated with Danon disease, e.g. Wolff–Parkinson–White syndrome. However, a systematic electrophysiological investigation of patients with Danon disease is lacking thus far. Methods and results Seven patients with Danon disease (4 males, 35.8 ± 10.8 years; 3 females, 51.3 ± 19.9 years) from 3 different families were studied. In all patients, the presence of Danon disease was confirmed by western blot of biopsy material or genetic testing. The patients were characterized by 12-lead electrocardiogram (ECG), Holter ECG, echocardiography, and serial implantable cardioverter defibrillator (ICD) interrogations (in ICD recipients). Al…
Ventricular Tachycardia and Early Fibrillation in Patients With Brugada Syndrome and Ischemic Cardiomyopathy Show Predictable Frequency-Phase Propert…
2015
[EN] Background¿ Ventricular fibrillation (VF) has been proposed to be maintained by localized high-frequency sources. We tested whether spectral-phase analysis of the precordial ECG enabled identification of periodic activation patterns generated by such sources. Methods and Results¿Precordial ECGs were recorded from 15 ischemic cardiomyopathy and 15 Brugada syndrome (type 1 ECG) patients during induced VF and analyzed in the frequency-phase domain. Despite temporal variability, induced VF episodes lasting 19.6±7.9 s displayed distinctly high power at a common frequency (shared frequency, 5.7±1.1 Hz) in all leads about half of the time. In patients with Brugada syndrome, phase analysis of …
Atrial fibrillation signatures on intracardiac electrograms identified by deep learning
2022
BACKGROUND: Automatic detection of atrial fibrillation (AF) by cardiac devices is increasingly common yet sub-optimally groups AF, flutter or tachycardia (AT) together as ‘high rate events’. This may delay or misdirect therapy. OBJECTIVE: We hypothesized that deep learning (DL) can accurately classify AF from AT by revealing electrogram (EGM) signatures. METHODS: We studied 86 patients in whom the diagnosis of AF or AT was established at electrophysiological study (25 female, 65 ± 11 years). Custom DL architectures were trained to identify AF using N = 29,340 unipolar and N = 23,760 bipolar EGM segments. We compared DL to traditional classifiers based on rate or regularity. We explained DL …
The total absence of atrial automaticity in a child with sinus node dysfunction
2007
Background A routine sports evaluation identified constant alternation between a junctional and idioventricular rhythm in a 9-year-old child. During exercise testing, electrography demonstrated that the child was in junctional rhythm without any apparent P waves, and had a reduced increase in heart rate. Endocardial atrial pacing captured the atrium and demonstrated that atrioventricular conduction was normal, but the recovery time of the ectopic rhythm was very long. Three-dimensional electrophysiological mapping revealed 1:1 retrograde homogeneous conduction through the right atrium. Investigations Electrocardiography, Holter monitoring, echocardiography, exercise stress testing, atrial p…
Resting Electrocardiogram and Blood Pressure in Young Endurance and Nonendurance Athletes and Nonathletes.
2020
Context Much information is available on electrocardiogram (ECG) and blood pressure (BP) changes in senior athletes. However, corresponding data on adolescent athletes are scarce. Objective To study the differences in resting ECG and BP values among adolescent endurance athletes, nonendurance athletes, and nonathletes. Design Cross-sectional study. Setting A total of 154 youth sports clubs in Finland and 100 secondary schools for comparison data. Patients or Other Participants We recruited young athletes (n = 410) aged 14 to 16 years in 10 popular sport disciplines, including winter and summer as well as team and individual sports, and categorized them as endurance or nonendurance sports. …
Lack of effect of azithromycin on QT interval in children: a cohort study.
2016
Macrolides are a group of antimicrobial drugs used widely, being well known for their adverse cardiac effects. Erythromycin and clarithromycin are most commonly associated with these conditions. In recent years, azithromycin (AZM) has been assessed because of its possible relation to arrhythmias (mainly QT interval prolongation) and risk of cardiovascular death.1 The pharmacodynamics of these effects is complex and the occurrence of cardiovascular death is unpredictable.2 However, all published manuscripts on the cardiac effects of AZM to date are cases in adults or …
Deterioration of organization in the first minutes of atrial fibrillation: A beat-to-beat analysis of cycle length and wave similarity
2007
Deterioration of AF Organization. Introduction: It has been recently suggested that many episodes of atrial fibrillation (AF) may be partially organized at the onset and thus more suitable for antitachycardia pacing therapy. Nevertheless, the time course of organization in the first minutes of AF has not been quantified yet. Methods and Results: Twenty episodes of paroxysmal AF were studied. Electrograms were recorded from the right atrium (RA), distal (CSd), and proximal coronary sinus (CSp). The time course of AF cycle length (AFCL) and the regularity of wave morphology (similarity index S) were beat-to-beat measured at each recording site during the first 7 minutes of AF. AFCL and S show…
Impact of biatrial defragmentation in patients with paroxysmal atrial fibrillation: Results from a randomized prospective study
2014
Single procedure success rates of pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF) are still unsatisfactory. In patients with persistent atrial fibrillation (AF), ablation of complex fractionated atrial electrograms (CFAEs) after PVI results in improved outcomes.We aimed to investigate if PAF-patients with intraprocedurally sustained AF after PVI might benefit from additional CFAE ablation.A total of 1134 consecutive patients underwent a first catheter ablation procedure of PAF between June 2008 and December 2012. In most patients, AF was either not inducible or terminated during PVI. In 68 patients (6%), AF sustained after successful PVI. These patients …