Search results for "FIBRILLATION"
showing 10 items of 509 documents
The controversial relationship between exercise and atrial fibrillation: clinical studies and pathophysiological mechanisms
2015
Atrial fibrillation is the most common clinically significant arrhythmia observed both in the general population and in competitive athletes. The most important risk factors are all preventable by regular physical activity. However, although the benefits of moderate physical activity in controlling cardiovascular risk factors and decreasing the risk of atrial fibrillation have been extensively proved, concerns have arisen about the potential negative effects of vigorous exercise, particularly in endurance athletes. Furthermore, in a subset of patients with atrial fibrillation younger than 60 years, routine evaluation does not reveal any cardiovascular disease or any other known causal facto…
Evaluation of atrial function by 2D strain echocardiography in patients with atrial fibrillation
2012
Abstract Objectives To evaluate atrial function by 2D strain in patients with atrial fibrillation (AF) and normal or slightly increased atrial size and to verify whether lower atrial strain is associated with more frequent AF recurrences. Materials and methods We studied 50 patients with AF, mean age 59.6 ± 13 years and 50 age-and gender-matched controls. We analyzed left atrial function through 2Dstrain imaging, after the re-establishment of sinus rhythm (SR) and we investigated about the recurrences of the arrhythmia. Results Atrial strain (AS) was lower in AF patients vs controls (LA p Conclusions The assessment of atrial function by strain imaging might help to identify patients who nee…
Modifications in Ventricular Fibrillation and Capture Capacity Induced by a Linear Radiofrequency Lesion
2012
[EN] Introduction and objectives: An analysis was made of the effects of a radiofrequency-induced linear lesion during ventricular fibrillation and the capacity to capture myocardium through high-frequency pacing. Methods: Using multiple epicardial electrodes, ventricular fibrillation was recorded in 22 isolated perfused rabbit hearts, analyzing the activation maps upon applying trains of stimuli at 3 different frequencies close to that of the arrhythmia: a) at baseline; b) after radio-frequency ablation to induce a lesion of the left ventricular free wall (length=10 [1] mm), and c) after lengthening the lesion (length=23 [2] mm). Results: Following lesion induction, the regularity of the r…
A hybrid stimulation strategy for suppression of spiral waves in cardiac tissue
2011
International audience; Atrial fibrillation (AF) is the most common cardiac arrhythmia whose mechanisms are thought to be mainly due to the self perpetuation of spiral waves (SW). To date, available treatment strategies (antiarrhythmic drugs, radiofrequency ablation of the substrate, electrical cardioversion) to restore and to maintain a normal sinus rhythm have limitations and are associated with AF recurrences. The aim of this study was to assess a way of suppressing SW by applying multifocal electrical stimulations in a simulated cardiac tissue using a 2D FitzHugh-Nagumo model specially convenient for AF investigations. We identified stimulation parameters for successful termination of S…
Changes in the Spectral Characteristics of Ventricular Fibrillation in Lesions Produced by Radiofrequency Ablation. An Experimental Study
2008
INTRODUCTION AND OBJECTIVES Although electro- physiological databases contain information about changes in the time domain in lesions produced by radiofrequency ablation, very few data on changes in the frequency domain are available. The aim of this study was to investigate changes in the spectral characteristics of ventricular fibrillation in zones with radiofrequency lesions. METHODS Recordings of ventricular fibrillation were obtained in 11 isolated perfused rabbit heart preparations using a multiple epicardial electrode located on the left ventricular free wall. Spectral parameters derived by Fourier analysis before and after the creation of transmural radiofrequency lesions were compa…
Cardiac arrest in special circumstances
2021
Purpose of review European Resuscitation Council Guidelines for Cardiopulmonary Resuscitation prioritize treatments like chest compression and defibrillation, known to be highly effective for cardiac arrest from cardiac origin. This review highlights the need to modify this approach in special circumstances. Recent findings Potentially reversible causes of cardiac arrest are clustered into four Hs and four Ts (Hypoxia, Hypovolaemia, Hyperkalaemia/other electrolyte disorders, Hypothermia, Thrombosis, Tamponade, Tension pneumothorax, Toxic agents). Point-of-care ultrasound has its role in identification of the cause and targeting treatment. Time-critical interventions may even prevent cardiac…
Erstdefibrillation durch Not�rzte oder durch Rettungsassistenten?
1994
In a controlled prospective randomized study, defibrillation by emergency medical technicians (EMTs) was compared with the current standard of care in Germany (basic life support by EMTs and defibrillation by emergency physicians only) in order to answer the following questions: 1. Does EMT defibrillation improve the survival rate and long-term prognosis of patients in ventricular fibrillation as compared to the current German standards in resuscitation (basic life support by EMTs and defibrillation by emergency physicians)? 2. Are the prerequisites for the use of semiautomatic defibrillators fulfilled in the emergency medical systems (EMS) of the participating centers? Methods. The study p…
Multicenter, Randomized, Controlled Trial of 150-J Biphasic Shocks Compared With 200- to 360-J Monophasic Shocks in the Resuscitation of Out-of-Hospi…
2000
Background —In the present study, we compared an automatic external defibrillator (AED) that delivers 150-J biphasic shocks with traditional high-energy (200- to 360-J) monophasic AEDs. Methods and Results —AEDs were prospectively randomized according to defibrillation waveform on a daily basis in 4 emergency medical services systems. Defibrillation efficacy, survival to hospital admission and discharge, return of spontaneous circulation, and neurological status at discharge (cerebral performance category) were compared. Of 338 patients with out-of-hospital cardiac arrest, 115 had a cardiac etiology, presented with ventricular fibrillation, and were shocked with an AED. The time from the e…
Principles of Rhythm Management in Patients with Atrial Fibrillation
2020
Abstract Atrial fibrillation is a multilateral arrhythmia, which causes the clinician to encounter difficulties in its therapeutic approach for each new patient. The purpose of this paper aims in particular at evaluating the management of atrial fibrillation, namely its cardioversion and rhythm control. The population study consisted of 50 patients diagnosed with atrial fibrillation, who underwent transesophageal echocardiographic investigation before cardioversion. All of these patients had transesophageal echocardiography. Certain echocardiographic parameters, such as the size of the left atrium, the presence of intracavitary thrombi, the left atrial appendage flow velocity, and the prese…
Electrocardiography for Assessment of Hypertensive Heart Disease: A New Role for an Old Tool
2016
Left ventricular (LV) hypertrophy (LVH), detected either by electrocardiography (ECG) or echocardiography (ECHO), has long been recognized as a powerful predictor of serious cardiovascular (CV) sequelae. A very large and highly consistent body of evidence indicates that LVH is not only an adaptation to increased hemodynamic load in hypertension, but is also independently associated with an enhanced risk for myocardial infarction, cardiac sudden death, congestive heart failure, and stroke in the general population, as well as in patients with systemic hypertension, coronary heart disease, chronic kidney disease, and atrial fibrillation. Intriguingly, the cumulative incidence of cardiovascula…