Search results for "Unstable"
showing 10 items of 111 documents
Can ECG-gated MDCT be considered an obligatory step to plan and manage a new chest-pain unit?
2007
The recent improvements in multi-detector computed tomography technology and its application in cardiac field allow to consider this non-invasive imaging technique as a promising comprehensive method for detecting significant coronary stenoses in a chest-pain unit. The possibility to use the ECG-synchronisation acquisition protocol, normally limited to the cardiac volume, for the entire thoracic vascular system should have the remarkable potential to reduce invasive and non-invasive procedures actually used to investigate acute chest pain and the number of unnecessary hospital admissions without reducing appropriate admissions in patients with chest pain.
Comprehensive cardiovascular ECG-gated MDCT as a standard diagnostic tool in patients with acute chest pain
2007
Acute myocardial infarction, pulmonary embolism, and aortic dissection are diseases associated with acute chest pain and may lead to severe morbidity and mortality. These diseases may not be trivial to diagnose in the settings of emergency room. ECG-gated multi-detector computed tomography (MDCT), already established for the assessment of pulmonary embolism and aortic dissection, provides reliable information regarding the triage of patients with acute coronary syndrome in the emergency room. MDCT recently appeared to be logistically feasible and a promising comprehensive method for the evaluation of cardiac and non-cardiac chest pain in emergency department patients. The possibility to sca…
Efficacy of coronary revascularization in patients with acute chest pain managed in a chest pain unit.
2009
To investigate the safety of discharge of patients deemed at low risk of cardiac events after evaluation in a chest pain unit and to determine the prognostic effect of revascularization of patients deemed at high risk.The study population consisted of 1088 patients presenting at the emergency department from January 15, 2001, to September 1, 2006, with chest pain but without ischemia on electrocardiography or troponin elevation. Patients were managed by a chest pain unit protocol that included early exercise testing. Three groups of patients were distinguished: (1) those discharged after exercise testing (424 [39%]); (2) those in whom unstable angina was ruled out after in-hospital evaluati…
Unstable shoe construction: influence on gait and posture
2011
Footwear, in one form or another, have been around for millennia. The advancements in the technology have made possible the transformation of animal skin and fur wrapped around feet by our ancestors into modern-day marvels of athletic shoes. Arguably one of the most pronounced innovations in the field of footwear design is the introduction of unstable shoe construction (USC), over the last few decades. Most widely investigated shoes are the Masai Barefoot Technology (MBT) shoes. Numerous scientific studies conducted on these shoes have revealed their effects on human gait and posture in healthy and morbid populations. peerReviewed
Expert system for predicting unstable angina based on Bayesian networks
2013
The use of computer-based clinical decision support (CDS) tools is growing significantly in recent years. These tools help reduce waiting lists, minimise patient risks and, at the same time, optimise the cost health resources. In this paper, we present a CDS application that predicts the probability of having unstable angina based on clinical data. Due to the characteristics of the variables (mostly binary) a Bayesian network model was chosen to support the system. Bayesian-network model was constructed using a population of 1164 patients, and subsequently was validated with a population of 103 patients. The validation results, with a negative predictive value (NPV) of 91%, demonstrate its …
Time-delay control for stabilization of the Shapovalov mid-size firm model
2020
Control and stabilization of irregular and unstable behavior of dynamic systems (including chaotic processes) are interdisciplinary problems of interest to a variety of scientific fields and applications. Using the control methods allows improvements in forecasting the dynamics of unstable economic processes and offers opportunities for governments, central banks, and other policy makers to modify the behaviour of the economic system to achieve its best performance. One effective method for control of chaos and computation of unstable periodic orbits (UPOs) is the unstable delay feedback control (UDFC) approach, suggested by K. Pyragas. This paper proposes the application of the Pyragas' me…
The Lorenz system : hidden boundary of practical stability and the Lyapunov dimension
2020
On the example of the famous Lorenz system, the difficulties and opportunities of reliable numerical analysis of chaotic dynamical systems are discussed in this article. For the Lorenz system, the boundaries of global stability are estimated and the difficulties of numerically studying the birth of self-excited and hidden attractors, caused by the loss of global stability, are discussed. The problem of reliable numerical computation of the finite-time Lyapunov dimension along the trajectories over large time intervals is discussed. Estimating the Lyapunov dimension of attractors via the Pyragas time-delayed feedback control technique and the Leonov method is demonstrated. Taking into accoun…
Utilidad de la troponina I para predecir la disfunción sistólica en los síndromes coronarios agudos. Resultados de un estudio prospectivo y cuantitat…
2003
The relationship between troponin I and systolic function (quantitative contrast ventriculography) was evaluated in 137 consecutive patients with a first acute coronary syndrome (60 with and 77 without ST elevation). In general, a larger troponin I peak value was related with a more depressed ejection fraction and poorer regional systolic function (p < 0.0001). Nevertheless, this correlation was weaker than expected, especially in those cases without ST-segment elevation, suggesting that other factors apart from systolic dysfunction must be taken into account in order to explain the worse prognosis of those patients with increased serum levels of this marker of myocardial damage.
Pronóstico a corto plazo de los pacientes ingresados por probable síndrome coronario agudo sin elevación del segmento ST. Papel de los nuevos marcado…
2002
Objectives. The relative value of classic markers, myocardial damage variables, and levels of acute-phase reactants in establishing the pre-discharge prognosis of acute coronary syndrome without ST-segment elevation was analyzed. Method. We prospectively studied 385 consecutive patients admitted from our chest pain unit with a highprobability diagnosis of acute coronary syndrome without ST-segment elevation. The clinical and electrocardiographic data, myocardial damage markers (troponin I, CK-Mb mass, myoglobin), and acute-phase reactants (high-sensitivity C-reactive protein, fibrinogen) were recorded. Results. During admission, 15 deaths (3.9%) and 16 complicative infarctions (4.2%) occurr…
Why does C-reactive protein increase in non-ST elevation acute coronary syndromes?
2003
Abstract Introduction: C-reactive protein is an important prognostic indicator for early risk stratification in patients with an acute coronary syndrome. The mechanisms underlying the elevation of C-reactive protein in these patients have not been fully understood. We studied the factors related to the increase of this acute-phase reactant. Methods and Results: Within a single-centre registry, 419 consecutive patients admitted for a non-ST elevation acute coronary syndrome were studied. Serum high sensitivity C-reactive protein was measured late (median 3 days) after admission. Clinical, electrocardiographic, biochemical and angiographic variables were recorded. In the multivariate analysis…