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Results 901 - 950 of 1906
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Haraldsson Henrik - - 2004
We use artificial neural networks (ANNs) to detect signs of acute myocardial infarction (AMI) in ECGs. The 12-lead ECG is decomposed into Hermite basis functions, and the resulting coefficients are used as inputs to the ANNs. Furthermore, we present a case-based method that qualitatively explains the operation of the ANNs, ...
Medvegy Mihály - - 2004
BACKGROUND: Body surface potential mapping has been shown to be a useful tool in the diagnosis and localization of remote non-Q wave and Q wave myocardial infarction, but human expertise is required to interpret the maps. OBJECTIVE: To identify quantitative body surface potential mapping parameters that could enable a computer-based ...
Strohmer Bernhard - - 2004
The J wave is a deflection that appears on the surface ECG as a late delta wave following the QRS complex. Also known as an Osborn wave, the J wave has been observed in various conditions and diseases. Our case highlights the typical electrocardiographic manifestations of hypothermia including the J ...
Toh Khay-Wee - - 2004
Arrhythmogenic right ventricular dysplasia is an inherited disease causing fatty replacement of heart tissue. This disease often presents as T-wave inversion in the anterior leads of the electrocardiogram (ECG) with life-threatening ventricular arrhythmias. In older patients, progressive right and left ventricular failure can develop. This is a case report of ...
Hsu Steve S - - 2004
The implantable cardioverter defibrillator is the treatment of choice for patients with ventricular tachycardia, especially in the setting of structural heart disease, but inappropriate therapy continues to be a problem. In this report we describe a short case series of patients who presented with T wave oversensing. We propose a ...
Ammar Khawaja Afzal - - 2004
BACKGROUND: Unrecognized myocardial infarctions (UMI) are detected by surveillance electrocardiograms (ECGs). In epidemiologic studies, different sets of ECG criteria have been used to define myocardial infarction, possibly contributing to significant differences in prevalence estimates and risk factor associations. We sought to summarize the rationale behind the various UMI-ECG definitions and ...
O'Brien Kevin E - - 2004
Electroconvulsive therapy (ECT) can lead to ST depression and arrhythmias in patients with coronary artery disease, most likely secondary to increased myocardial oxygen demand. This report describes a case of ECT-associated, global T-wave inversions in a patient with chronic atrial fibrillation treated with digoxin. Laboratory evaluation and echocardiography were normal. ...
Crescenzi Giuseppe - - 2004
OBJECTIVE: The appearance of new Q waves on the electrocardiogram (ECG) after cardiac surgery has been traditionally considered a sign of major myocardial tissue damage. The aim of this study was to investigate the clinical significance of new Q waves appearing following cardiac surgery and to correlate them with the ...
Dekker Lukas R C - - 2004
We describe a case of potentially fatal undersensing of VF by a third generation ICD with predetermined automatic gain control. In this patient, ventricular sensing was optimal, as R wave amplitudes during sinus rhythm were at least 16 mV. Cyclical, high amplitude signals during VF elevated the sensing floor to ...
Carley Simon D - - 2004
We present the evolutionary changes of isolated right ventricular infarction (RVI) in a patient undergoing right coronary artery stenting using a novel imaging system. Twelve ECG and body surface maps were recorded at 30-s intervals during right coronary angioplasty, during which a right ventricular branch of the right coronary artery ...
Salles Gil F - - 2004
The T-wave axis shift has been reported to represent a general marker of ventricular repolarization abnormalities and a potential indicator of increased risk for cardiovascular mortality. We assessed the prognostic importance of the T-wave axis deviation for mortality rate in patients with chronic Chagas' disease. In a long-term follow-up prospective ...
Sucu Mehmet Murat - - 2004
Although the damage in myocardial infarction has been demonstrated to be related with the magnitude and number of ST elevation, its relation with terminal distortion of QRS is unclear. The relationship between terminal QRS distortion in ECGs on admission and the results of early low dose dobutamine stress echocardiography (LDSE) ...
Dori G - - 2004
The goal of this study was to evaluate the role of a computerised, non-invasive ECG method for detecting acute coronary occlusion (ACO). Ninety-five standard ECG leads were recorded, before and during ACO, from 18 patients undergoing balloon angioplasty. ECG amplitude and derivative parameters were calculated for the ORS, ST and ...
Dvir Eran - - 2004
The main purpose of this study was to describe electrocardiographic (ECG) changes in canine babesiosis, and to relate these to clinical severity, outcome and cardiac pathology. Four groups of dogs with babesiosis were studied: mild to moderate anemia, severe anemia, concurrent autoagglutination and concurrent complications. Lead II ECG was recorded ...
Kim Chang-Soo - - 2004
Micromachined probes, with iridium (Ir) microelectrodes on silicon shanks, were evaluated to assess their suitability for cardiac electrogram recording. The electrochemical activation (anodic oxidation) procedure for the circular Ir microelectrode was investigated using the square wave potential according to the electrode size, number of cycles, and cathodic-anodic potential level of ...
Zafrir Barak - - 2004
BACKGROUND: The common electrocardiographic subclassification of anterior acute myocardial infarction (AMI) is not reliable in presenting the exact location of the infarct. We investigated the relationship between predischarge electrocardiographic patterns and the extent and location of perfusion defects in 55 patients with first anterior AMI. METHODS: Predischarge electrocardiogram was examined ...
Madias John E - - 2004
There is recent evidence that anasarca peripheral edema, irrespective of its etiology, attenuates ECG QRS potentials. Pulmonary edema (PE) also is thought to cause reduction in the amplitude of QRS complexes. The case reported herein is of a patient with severe PE, hypertension, left ventricular diastolic dysfunction, and no peripheral ...
Michaelides Andreas - - 2004
OBJECTIVE: It is known that exercise-induced ischemia in patients with coronary artery disease (CAD) may produce QRS prolongation in the surface electrocardiogram (ECG). To investigate the presence of exercise-induced Q-wave prolongation in patients with single-vessel CAD and Q-wave myocardial infarction (MI), in association with the presence of reversible perfusion defects ...
Meenakshi-Sundaram S - - 2004
BACKGROUND: Wilson's disease is known for its protean manifestations; however electrocardiographic abnormalities have not received much attention. AIM: To evaluate the various electrocardiographic (ECG) changes in patients with Wilson's disease. METHOD: The resting ECGs of 50 patients with Wilson's disease were systematically analyzed independently by three observers after excluding other ...
Lo Huey-Ming - - 2004
Surgically induced abnormalities in atrial conduction could result in unusual P wave changes. A 31-year-old woman underwent concomitant mitral valve surgery and atrial compartment operation for mitral stenosis and atrial fibrillation (AF). After operation, the AF was successfully converted to sinus rhythm, whereas an unusual electrocardiogram (ECG) with a discrete ...
Madias John E - - 2004
We describe a patient with coronary artery disease who showed transiently augmented R-waves in his electrocardiogram (ECG) during the course of an exercise treadmill test (ETT), an ECG pattern occasionally associated with the hyperacute phase of myocardial infarction and variant angina. This change in the R-waves was noted in II, ...
Pascual J García - - 2004
We studied prospectively 35 elder women aged 65-82 years, with isolated severe symptomatic aortic stenosis, referred for aortic valve surgery. We assessed diastolic function by TEE before and after cardiac surgery, although follow-up data were collected in 26 patients. The examination was performed prior to surgery and 6 months after. ...
Massel D - - 2004
BACKGROUND: Left ventricular function is the most important determinant of prognosis following myocardial infarction. METHODS: A prospective analytical cohort study of 33 cardiac care unit survivors of acute myocardial infarction was performed to assess the accuracy, reproducibility and observer variation of the bedside Valsalva response in predicting an ejection fraction ...
Kodama Makoto - - 2004
Progressive heart failure and ventricular fibrillation are major causes of death in patients with chronic heart failure. Mechanical alternans (pulsus alternans) has been observed in patients with severe congestive heart failure. Visible T wave alternans occasionally is a precursor of ventricular fibrillation. We investigated the occurrence of both cardiac alternans ...
Costantini Marcello - - 2004
BACKGROUND: Pulmonary embolism (PE) afflicts millions of individuals worldwide. Electrocardiography along with chest X-ray and arterial blood gas analysis represent the basic examinations to reinforce the clinical suspicion of PE. We describe the electrocardiographic (ECG) features in a series of patients with PE and a critical clinical presentation. METHODS: We ...
Voon Wen-Chol - - 2004
BACKGROUND: The actual relationship between the interval change of myocardial thallium 201 (Tl-201) radioactivity in the infarct area and the pattern of Q-wave regression is still unknown. This study was conducted to evaluate their relationship after acute myocardial infarction (AMI). METHODS AND RESULTS: A total of 30 patients who had ...
Schlegel Todd T TT Neuroautonomic Laboratory, NASA Johnson Space Center, Houston, Tex 77058, USA. - - 2004
Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, ...
Yang Hua - - 2004
OBJECTIVES: We investigated whether patients with non-Q-wave myocardial infarction (NQMI) have more ischemic viable myocardium (IVM) than patients with Q-wave myocardial infarction (QMI). BACKGROUND: Non-Q-wave myocardial infarction is associated with higher incidences of cardiac events than QMI, suggesting more myocardium at risk in NQMI. METHODS: To identify myocardial ischemia, hibernation, ...
Davis T M E - - 2004
AIMS/HYPOTHESIS: Our study investigated the prognosis of Type 2 diabetic patients with silent myocardial infarction in a community-based cohort. METHODS: We analysed data from 1269 patients with Type 2 diabetes mellitus from a community-based observational study of diabetes care, control and complications. Silent myocardial infarction was defined as Q waves ...
Hisamatsu Kenichi - - 2004
BACKGROUND: It has been reported that recording electrocardiograms (ECGs) in the 3rd intercostal space (ICS) is one method that can be used for detecting Brugada syndrome; however, the prevalence of Brugada-type ECGs recorded in the 3rd ICS and the usefulness of recording the ECG in the 3rd ICS in accordance ...
Wisten A - - 2004
OBJECTIVES: To study electrocardiogram (ECG) in relation to forensic diagnosis in young persons who suffered a sudden cardiac death (SCD) in Sweden during 1992-99. DESIGN: A register study of a national database of forensic medicine in Sweden, selecting all cases of SCD 15-35 years of age. In this group, 12-lead ...
Kurisu Satoshi - - 2004
BACKGROUND: The time course of the electrocardiographic (ECG) changes in patients with tako-tsubo syndrome remains unknown. METHODS AND RESULTS: In the present study, 16 patients with tako-tsubo syndrome and 15 patients with anterior acute myocardial infarction with minimal enzymatic release (minimal AMI) were evaluated. Left ventricular dysfunction dramatically resolved approximately ...
Ng Jason - - 2004
BACKGROUND: The aim of this study was to examine atrial organization from vectorcardiograms (VCGs) derived from the surface ECG of atrial fibrillatory waves. METHODS: We retrieved ECGs recorded during ventricular asystole from 22 patients with AF undergoing ablation of the AV junction. The synthesized VCG of each f-wave cycle of ...
MacKenzie Ross - - 2004
Tall R waves in lead V1 present the life insurance company medical director with a diagnostic dilemma. This ECG pattern may be present in applicants with right bundle branch block, right ventricular hypertrophy, Wolff-Parkinson-White syndrome, posterior myocardial infarction, hypertrophic cardiomyopathy, muscular dystrophy, dextrocardia, misplaced precordial leads, as well as in ...
MacAlpin Rex N - - 2004
BACKGROUND: In the absence of other electrocardiographic (ECG) abnormalities, QS deflections simultaneously in both of the leads V1-V2 may have multiple possible causes. Despite much information in the literature indicating that this is an unlikely pattern for pure septal infarction, such an ECG diagnosis is frequently given. METHODS: Ninety-nine cases ...
Fenici R - - 2004
Recent studies have reported better sensitivity of magnetocardiographic (MCG) mapping, as compared to ECG, in detecting ventricular repolarization (VR) abnormalities due to myocardial ischemia in patients (pts) with Ischemic Heart Disease (IHD). For quick data reduction, automatic analysis of MCG mapping is mostly used. The aim of our study was ...
Pueyo E - - 2004
OBJECTIVES: In this work we studied the temporal evolution of changes in the electrocardiogram (ECG) as a consequence of the induced ischemia during prolonged coronary angioplasty, comparing the time course of indexes reflecting depolarization and those reflecting repolarization. METHODS: We considered both local (measured at specific points of the ECG) ...
Selvanayagam Joseph B - - 2004
AIM: Delayed enhancement MRI (DE-MRI) of the heart has been shown to reliably identify areas of irreversible myocardial damage. We sought to determine if the term anteroseptal MI is appropriate by correlating electrocardiographic, angiographic, cine MRI and DE-MRI findings. METHODS AND RESULTS: Nineteen patients admitted to our hospital with their ...
Fensli R - - 2004
Development of new wearable biomedical sensors within a wireless infrastructure opens up possibilities for new telemedical applications leading to significant improvements in continuous monitoring, and thereby to better quality of patient care. In this paper we describe a new concept for a wireless electrocardiogram (ECG) system intended for continuous monitoring ...
Besio Walter G - - 2004
Laplacian ECG (LECG) is a new technique for detecting cardiac electrical activity. An algorithm was designed utilizing ECG QRS complexes to determine where cardiac activity was likely present in the LECG. The recurrent property of ECG is exploited by this new algorithm for the detection of the QRS complexes by ...
Forouhar A S - - 2004
The zebrafish (Danio rerio) has emerged as one of the primary experimental models of developmental cardiovascular research. Recent progress in flow visualization techniques along with the existing genetic map of the species has made zebrafish amenable to a variety of experiments relating cardiac developmental structure and function. One essential tool ...
Mohiti Javad - - 2004
Measurement of cardiac markers is an index of care standard in the assessment and diagnosis of cardiovascualr disease. Two of the major cardiac markers are Creatine Kinase isoenzyme CK-MB and Troponin T, which are extensively used in the diagnosis of heart disease. The release of Troponin T and creatine kinase ...
Alexander John H - - 2003
PURPOSE: To investigate the prognostic importance of new small Q waves following an acute coronary syndrome. METHODS: We assessed 6-month mortality in 10501 patients with non-ST-elevation acute coronary syndromes who had survived 30 days and had both admission and 30-day electrocardiograms. Patients were stratified by whether they had no new ...
Schumacher Juergen - - 2003
In a prospective study, eight (four males and four females) healthy, adult captive cheetahs (Acinonyx jubatus) were immobilized with a combination of tiletamine-zolazepam (4 mg/kg, i.m.), administered with a remote drug delivery system, to define normal cardiac morphology and function. Standard lateral and ventrodorsal (VD) radiographs were then taken to ...
Madias John E - - 2003
OBJECTIVE: Precordial ECGs reveal significant intrasubject variability due to the inexact employment of the recommended V(1)-V(6) chest landmarks. Also, as per the Einthoven law, the six limb leads can be derived from leads 1 and 2. The purpose of this study was to evaluate whether the 12-lead ECG could be ...
Dinckal M H - - 2003
A 44-year-old woman presented with sudden onset of chest pain, headache and nausea. Physical examination was remarkable for mild hypotension and tachycardia. ECG demonstrated sinus tachycardia with poor R wave progression in precordial leads and T wave inversion in leads V1-3. Cardiac enzymes were raised. Echocardiographic examination revealed normal cavity ...
Rudiger Alain - - 2003
Electrocardiographic (ECG) artifacts resulting from misplacements of electrodes are frequent, difficult to detect, and can become of clinical importance. We investigated 2 healthy volunteers and 3 patients with ECG signs of inferior myocardial scars. We exchanged the peripheral electrodes in a defined manner and investigated the resulting ECG for morphology ...
Bountioukos M - - 2003
OBJECTIVE: To quantify regional left ventricular (LV) function and contractile reserve in Q wave and non-Q wave regions in patients with previous myocardial infarction. DESIGN: An observational study. SETTING: Tertiary care centre. PATIENTS: 81 patients with previous myocardial infarction and depressed LV function. INTERVENTIONS: All patients underwent surface ECG at ...
Somers Michael P - - 2003
In the evaluation of the patient with chest pain, the 12-lead electro cardiogram is a less-than-(ECG) perfect indicator of acute myocardial infarction (AMI), particularly when used early in the course of the acute ischemic event; this relative insensitivity for AMI results from many different issues, including a less-than-optimal imaging of ...
Horigome Hitoshi - - 2003
A 14-year-old boy with coarctation of the aorta who showed repeat ventricular fibrillation during anesthesia, and ultimately sudden cardiac death in school, is presented. Electrocardiography showed J waves in the left precordial leads, which became prominent after an episode of ventricular fibrillation. While some of the clinical features and electrophysiological ...
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