Search results for " fibrillation"

Relationship between carotid intima-media thickness and non valvular atrial fibrillation type.

2015

OBJECTIVE: Carotid intima-media thickness (cIMT) is a surrogate marker of subclinical atherosclerosis and it is able to predict both coronary and cerebral vascular events. No data exist on the association between cIMT and non valvular atrial fibrillation (NVAF) type. We conduct this study with the aim to analyze the association between abnormal cIMT and NVAF type. METHODS: A cross-sectional study of the "Atrial fibrillation Registry for Ankle-brachial index Prevalence Assessment-Collaborative Italian Study (ARAPACIS)" has been performed. Among 2027 patients enrolled in the ARAPACIS, 673 patients, who underwent carotid ultrasound examination to assess cIMT, were included in the study. RESULT…

Management of Patients with Asymptomatic and Symptomatic Carotid Artery Disease: Update on Anti-Thrombotic Therapy

2019

AbstractThe most common causes of ischaemic stroke are represented by carotid artery atherosclerotic disease (CAAD) and atrial fibrillation. While oral anticoagulants substantially reduce the incidence of thromboembolic stroke (< 1%/year), the rate of ischaemic stroke and other cardiovascular disease events in patients with CAAD remains high, ranging from 8.4 to 18.1 events per 100 patient-years. Similar to any other atherosclerotic disease, anti-thrombotic therapies are proposed for CAAD to reduce stroke and other cardiovascular events. The 2017 European Society of Cardiology (ESC)/European Society for Vascular Surgery (ESVS) guidelines recommend for patients with asymptomatic CAAD ≥60%…

Electrocardiographic abnormalities, preclinical carotid atherosclerosis and cardiovascular risk in an apparently healthy real-world population. Data …

2021

Background: Cardiovascular diseases (CVDs) represent important causes of morbidity and mortality. Our study aimed to evaluate cardiovascular risk using the EuroSCORE, ECG and carotid ultrasound for prevention purpose in a population of companions aged 50-70 years, asymptomatic and without CVD. Methods: History of CVD, risk factors (RF), ECG and carotid ultrasound were evaluated. Intima-media thickness (IMT) was defined as wall thickness >0.9 mm, while focal thickening ≥1.5 mm protruding into the lumen as asymptomatic carotid plaque (ACP). Results: Totally, 1860 subjects were screened. 393 (21.1%) had no RF, 780 (42%) hypertension, 571 (30.7%) hypercholesterolemia, 557 (29.9%) diabetes, 4…

Analyse et détection des électrogrammes complexes fractionnés en vue de soigner la fibrillation auriculaire à l'aide de techniques d'ablation par rad…

2013

This manuscript presents research on the analysis and the detection of Complex Fractionated Atrial Electrograms (CFAE). In the first part, following a presentation over Atrial Fibrillation (AF) mechanisms and bioelectrical signals, the most commonly used tools for analyzing CFAE are presented. Linear tools are initially applied to signals from AF ablation procedures, then nonlinear tools are shown and integrated intoa CFAE detection algorithm. This one is based on the quantification of electrogram recurrence properties. In the second part, the cell and cardiac muscle tissue are described and simulated using mathematical models. Models such as FitzHugh Nagumo, Aliev Panfilov and Courtemanche…

Heart rate response and functional capacity in patients with chronic heart failure with preserved ejection fraction

2018

Aims The mechanisms of exercise intolerance in heart failure with preserved ejection fraction (HFpEF) are not yet elucidated. Chronotropic incompetence has emerged as a potential mechanism. We aimed to evaluate whether heart rate (HR) response to exercise is associated to functional capacity in patients with symptomatic HFpEF. Methods and results We prospectively studied 74 HFpEF patients [35.1% New York Heart Association Class III, 53% female, age (mean ± standard deviation) 72.5 ± 9.1 years, and 59.5% atrial fibrillation]. Functional performance was assessed by peak oxygen consumption (peak VO2 ). The mean (standard deviation) peak VO2 was 10 ± 2.8 mL/min/kg. The following chronotropic pa…

Existence of metastable intermediate lysozyme conformation highlights the role of alcohols in altering protein stability.

2011

Alcohols have a manifold effect on the conformational and thermodynamic stability of native proteins. Here, we study the effect of moderate concentrations of trifluoroethanol (TFE) on the thermal stability of hen egg-white lysozyme (HEWL), by far-UV circular dichroism and by steady-state and time-resolved photoluminescence of intrinsic tryptophans. Our results highlight that TFE affects lysozyme stability by preferential solvation of the protein molecule. Furthermore, we discovered the existence at 20% TFE of an equilibrium partially folded state of lysozyme, intermediate between the native and the unfolded state. A three-state model is therefore used to interpolate the thermal denaturation…

Atrial activity extraction for atrial fibrillation analysis using blind source separation.

2004

This contribution addresses the extraction of atrial activity (AA) from real electrocardiogram (ECG) recordings of atrial fibrillation (AF). We show the appropriateness of independent component analysis (ICA) to tackle this biomedical challenge when regarded as a blind source separation (BSS) problem. ICA is a statistical tool able to reconstruct the unobservable independent sources of bioelectric activity which generate, through instantaneous linear mixing, a measurable set of signals. The three key hypothesis that make ICA applicable in the present scenario are discussed and validated: 1) AA and ventricular activity (VA) are generated by sources of independent bioelectric activity; 2) AA …

Feature Selection Methods to Extract Knowledge and Enhance Analysis of Ventricular Fibrillation Signals

2014

Improving diagnostic accuracy of MDCT coronary angiography in patients with mild heart rhythm irregularities using ECG editing

2006

OBJECTIVE. The objective of our study was to compare diagnostic accuracy of MDCT coronary angiography in a population of patients with mild heart rhythm irregularities before and after editing the ECG. SUBJECTS AND METHODS. Thirty-eight patients who underwent MDCT coronary angiography and conventional coronary angiography were enrolled in the study. The inclusion criterion was the presence of mild heart rhythm irregularities (i.e., premature beats; atrial fibrillation; mistriggering; or low heart rate, defined as 40 beats per minute or less) during the scan. All patients underwent MDCT with the following parameters: 16 detectors; collimation, 0.75 mm; gantry rotation time, 375 msec; 120 kV;…

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 …