Search results for "Cardiac"

Embryonic stem cell differentiation studied by FT-IR spectroscopy

2007

We propose, here, an FT-IR method to monitor the spontaneous differentiation of murine embryonic stem (ES) cells in their early development. Principal component analysis and subsequent linear discriminant analysis enabled us to segregate stem cell spectra into separate clusters corresponding to different differentiation times - and to identify the most significant spectral changes during differentiation. Between days 4 to 7 of differentiation, these spectral changes in the protein amide I band (1700-1600 cm(-1)) and in the nucleic acid absorption region (1050-850 cm(-1)) indicated that mRNA translation was taking place and that specific proteins were produced, reflecting the appearance of a…

Pacing ventricolare destro: una risorsa o una minaccia?

2005

Early after the beginning of the pacemaker era, endocardial right ventricular apex has been the most extensively used site for cardiac pacing because it was easily accessible and reliable in a long-term perspective. However many data have demonstrated that this kind of pacing is suboptimal from a physiologic point of view because it causes several adverse effects such as altered ventricular contraction geometry, mitral regurgitation, perfusion alterations and interference with myocardial ion channels which determine a worsening of left ventricular function. Several strategies have been proposed to solve these problems (alternative pacing sites, specific algorithms able to reduce the percent…

Segmentation Integrating Watershed and Shape Priors Applied to Cardiac Delayed Enhancement MR Images

2017

International audience; Background: In recent years, there has been a rapid rise in the use of shape priors applied to segmentation process of medical images. Previous approaches on left ventricle segmentation from Delayed-Enhancement Magnetic Resonance Imaging (DE-MRI) have focused on the extraction of myocardium or just diseased region in short axis orientation. However these studies did not take into account the segmentation of non-diseased myocardium from DE-MRI. The segmentation of non-diseased myocardium from DE-MRI, has some useful applications. For instance it can simplify the PET-MR registration process.Methods: This paper presents a novel semi-automatic segmentation method of non-…

Are the leukocyte telomere length attrition and telomerase activity alteration potential predictor biomarkers for sporadic TAA in aged individuals?

2014

A large variability in occurrence, complications, and age/gender manifestations characterizes individual susceptibility of sporadic thoracic aortic aneurysms (TAA), even in subjects with the same risk factor profiles. The reasons are poorly understood. On the other hand, TAA pathophysiology mechanisms remain unclear than those involved in abdominal aorta aneurysms. However, recent evidence is suggesting a crucial role of biological ageing in inter-individual risk variation of cardiovascular diseases, including sporadic TAA. Biological age rather than chronological age is a better predictor of vascular risk. Relevant assumptions support this concept. In confirming this evidence and our preli…

Convolutional Neural Network With Shape Prior Applied to Cardiac MRI Segmentation.

2019

In this paper, we present a novel convolutional neural network architecture to segment images from a series of short-axis cardiac magnetic resonance slices (CMRI). The proposed model is an extension of the U-net that embeds a cardiac shape prior and involves a loss function tailored to the cardiac anatomy. Since the shape prior is computed offline only once, the execution of our model is not limited by its calculation. Our system takes as input raw magnetic resonance images, requires no manual preprocessing or image cropping and is trained to segment the endocardium and epicardium of the left ventricle, the endocardium of the right ventricle, as well as the center of the left ventricle. Wit…

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 …

Fibrilación ventricular con parada cardiorrespiratoria durante la administración de dexmedetomidina

2015

Protocol of a multicenter international randomized controlled manikin study on different protocols of cardiopulmonary resuscitation for laypeople (MA…

2018

IntroductionOut-of-hospital cardiac arrest is one of the leading causes of death in industrialised countries. Survival depends on prompt identification of cardiac arrest and on the quality and timing of cardiopulmonary resuscitation (CPR) and defibrillation. For laypeople, there has been a growing interest on hands-only CPR, meaning continuous chest compression without interruption to perform ventilations. It has been demonstrated that intentional interruptions in hands-only CPR can increase its quality. The aim of this randomised trial is to compare three CPR protocols performed with different intentional interruptions with hands-only CPR.Methods and analysisThis is a prospective randomise…

Working in the mirror: The safety and effectiveness of closure access leading venous advanced gain new ability in a patient with dextrocardia

2018

The evolution of devices in serious cardiac rhythm pathology management and in other medicine areas and its optimal management have progressively become a worldwide serious challenge. We present an upgrading to dual chamber im-plantable cardioverter-defibrillator (ICD) without complications in a 68 year old woman through closure access leading venous advanced gain new ability, complementing the mechanical multiple venous entry-site approach extraction. This is another of the few cases present in literature about ICD in patients with dextrocardia and it focuses on the safety and effectiveness of our simple technique also in a patient with dextrocardia.

Coronary artery anomalies: incidence, pathophysiology, clinical relevance and role of diagnostic imaging

2006

Conventional coronary angiography is the gold standard for the diagnosis of coronary artery anomalies. Coronary anomalies are relatively rare findings in patients undergoing conventional coronary angiography for suspected obstructive coronary artery disease. Recently, the increasing performance of diagnostic techniques, such as electron beam tomography (EBT), magnetic resonance (MR) and, more recently, multislice computed tomography (MSCT), has enabled their application to cardiac imaging. MSCT, in particular, has a prominent role in coronary imaging due to its spatial and temporal resolution and three-dimensional capabilities. We report the incidence and pathophysiology of coronary artery …