• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 228
  • 64
  • 55
  • 18
  • 17
  • 15
  • 13
  • 13
  • 12
  • 12
  • 6
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 517
  • 407
  • 94
  • 74
  • 65
  • 64
  • 60
  • 59
  • 57
  • 55
  • 54
  • 53
  • 49
  • 48
  • 41
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Novel pacemaker mediated Arrhythmia w ithout v entriculoatrial c onduction c an i nduce a trial f ibrillation

Gjermeni, Erind 12 July 2022 (has links)
Moderne Herzschrittmacher sind mit zahlreichen Algorithmen ausgestattet, die sie zu bemerkenswerten therapeutischen und diagnostischen Werkzeugen machen. Die zunehmende Komplexität bringt jedoch unbeabsichtigt neue Herausforderungen mit sich. In dieser Arbeit beschreiben wir eine neue Herzschrittmacher-Induzierte Arrhythmie die oft zum Vorhofflimmern führt.:1. Introduction................................................................................................ 3 1.1. A flashback to the beginning of cardiac pacemakers ............................. 3 1.2. Early pacemakers and significant advances .......................................... 5 1.3. Fast-forward to modern pacemakers ...................................................... 6 1.4. Current challenges .................................................................................. 8 1.5. Identification of a new pacemaker induced arrhythmia .......................... 10 1.6. Methods and results ............................................................................... 11 1.7. Patient characteristics ............................................................................ 13
282

ASSOCIATIONS BETWEEN OBESITY, TYPE 2 DIABETES AND ATRIAL FIBRILLATION WITH ADIPOSE TISSUE AND EXERCISE AS THERAPEUTIC STRATEGIES

Dewal, Revati S. January 2021 (has links)
No description available.
283

Fibrillation of chain branched poly (lactic acid) with improved blood compatibility and bionic structure

Li, Z., Zhao, X., Ye, L., Coates, Philip D., Caton-Rose, Philip D., Martyn, Michael T. 25 May 2015 (has links)
Yes / Highly-oriented poly (lactic acid) (PLA) with bionic fibrillar structure and micro-grooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. In order to enhance the melt strength and thus obtain high orientation degree, PLA was first chain branched with pentaerythritol polyglycidyl ether (PGE). The branching degree as high as 12.69 mol% can be obtained at 0.5 wt% PGE content. The complex viscosity, elastic and viscous modulus for chain branched PLA were improved resulting from the enhancement of molecular entanglement, and consequently higher draw ratio can be achieved during the subsequent hot stretching. The stress-induced crystallization of PLA occurred during stretching, and the crystal structure of the oriented PLA can be attributed to the α′ crystalline form. The tensile strength and modulus of PLA were improved dramatically by drawing. Chain branching and orientation could significantly enhance the blood compatibility of PLA by prolonging clotting time and decreasing hemolysis ratio, protein adsorption and platelet activation. Fibrous structure as well as micro-grooves can be observed for the oriented PLA which were similar to intimal layer of blood vessel, and this bionic structure was considered to be beneficial to decrease the activation and/or adhesion of platelets.
284

In-vitro Untersuchung der HDL Funktionalität sowie der periphervenösen und atrialen Myeloperoxidase bei Patienten mit Vorhofflimmern

Holzwirth, Erik 06 December 2023 (has links)
Untersuchung von MPO sowie anti-inflammatorischer HDL Funktionalität bei Patienten mit Vorhofflimmern
285

Association of stroke lesion shape with newly detected atrial fibrillation: Results from the MonDAFIS study

Crespo Pimentel, Bernardo, Ingwersen, Thies, Häusler, Karl Georg, Schlemm, Eckhard, Forkert, Nils D., Rajashekar, Deepthi, Mouches, Pauline, Königsberg, Alina, Kirchhof, Paulus, Kunze, Claudia, Tütüncü, Serdar, Olma, Manuel C., Krämer, Michael, Michalski, Dominik, Kraft, Andrea, Rizos, Timolaos, Helberg, Torsten, Ehrlich, Sven, Nabavi, Darius G., Röther, Joachim, Laufs, Ulrich, Veltkamp, Roland, Heuschmann, Peter U., Cheng, Bastian, Endres, Matthias, Thomalla, Götz 21 November 2023 (has links)
Paroxysmal Atrial fibrillation (AF) is often clinically silent and may be missed by the usual diagnostic workup after ischemic stroke. We aimed to determine whether shape characteristics of ischemic stroke lesions can be used to predict AF in stroke patients without known AF at baseline. Lesion shape quantification on brain MRI was performed in selected patients from the intervention arm of the Impact of standardized MONitoring for Detection of Atrial Fibrillation in Ischemic Stroke (MonDAFIS) study, which included patients with ischemic stroke or TIA without prior AF. Multiple morphologic parameters were calculated based on lesion segmentation in acute brain MRI data. Multivariate logistic models were used to test the association of lesion morphology, clinical parameters, and AF. A stepwise elimination regression was conducted to identify the most important variables. A total of 755 patients were included. Patients with AF detected within 2 years after stroke (n=86) had a larger overall oriented bounding box (OBB) volume (p=0.003) and a higher number of brain lesion components (p=0.008) than patients without AF. In the multivariate model, OBB volume (OR 1.72, 95%CI 1.29–2.35, p<0.001), age (OR 2.13, 95%CI 1.52–3.06, p<0.001), and female sex (OR 2.45, 95%CI 1.41–4.31, p=0.002) were independently associated with detected AF. Ischemic lesions in patients with detected AF after stroke presented with a more dispersed infarct pattern and a higher number of lesion components. Together with clinical characteristics, these lesion shape characteristics may help in guiding prolonged cardiac monitoring after stroke.
286

Upstream Statin Therapy and Long-Term Recurrence of Atrial Fibrillation after Cardioversion: A Propensity-Matched Analysis

Fiedler, Lukas, Hallsson, Lára, Tscharre, Maximilian, Oebel, Sabrina, Pfeffer, Michael, Schönbauer, Robert, Tokarska, Lyudmyla, Stix, Laura, Haiden, Anton, Kraus, Johannes, Blessberger, Hermann, Siebert, Uwe, Roithinger, Franz Xaver 04 May 2023 (has links)
The relationship of statin therapy with recurrence of atrial fibrillation (AF) after cardioversion (CV) has been evaluated by several investigations, which provided conflicting results and particularly long-term data is scarce. We sought to examine whether upstream statin therapy is associated with long-term recurrence of AF after CV. This was a single-center registry study including consecutive AF patients (n = 454) undergoing CV. Cox regression models were performed to estimate AF recurrence comparing patients with and without statins. In addition, we performed a propensity score matched analysis with a 1:1 ratio. Statins were prescribed to 183 (40.3%) patients. After a median follow-up period of 373 (207–805) days, recurrence of AF was present in 150 (33.0%) patients. Patients receiving statins had a significantly lower rate of AF recurrence (log-rank p < 0.001). In univariate analysis, statin therapy was associated with a significantly reduced rate of AF recurrence (HR 0.333 (95% CI 0.225–0.493), p = 0.001), which remained significant after adjustment (HR 0.238 (95% CI 0.151–0.375), p < 0.001). After propensity score matching treatment with statins resulted in an absolute risk reduction of 27.5% for recurrent AF (21 (18.1%) vs. 53 (45.7%); p < 0.001). Statin therapy was associated with a reduced risk of long-term AF recurrence after successful cardioversion.
287

Towards the Prediction of Atrial Fibrillation Using Interpretable ECG Features

Hammer, Alexander, Malberg, Hagen, Schmidt, Martin 14 March 2024 (has links)
Atrial fibrillation (AF) is our society's most common cardiac arrhythmic disease, leading to increased morbidity and mortality. Predicting AF episodes during sinus rhythm based on electrocardiograms (ECGs) allows timely interventions. It is known, that changes in selected ECG morphology features are a predictor for the onset of AF, but no systematic investigation of different ECG features' temporal changes has been performed so far. We split sinus rhythm episodes of 60 minutes preceding AF from the MIT-BIH AF database into segments of 5 minutes with 50% overlap (n=644) and calculated 155 features of different domains per segment. Logistic regression analyses between the segments preceding AF and others revealed the most significant effects for segments ending 5 minutes before AF onset, with PQ interval slope (p < 0.01), PQ interval correlation (p < 0.05), and median RR time (p < 0.05) being the most relevant features. A decision tree ensemble, trained with all features, achieved an accuracy of 0.87 when distinguishing 8 segment clusters. Our results confirm expected changes in ECG features (e.g., PQ interval) before AF episodes, indicating impaired atrial excitation, and show that the combination of interpretable features is sufficient to discriminate at different points in time before AF onset. For advanced analyses, more extensive databases should be included.
288

Characterization of Conduction Abnormalities in Canine Models of Atrial Arrhythmias

Ryu, Kyungmoo 07 April 2005 (has links)
No description available.
289

Quantitative Electrocardiography for Prediction of Postoperative Atrial Fibrillation after Cardiac Surgery

Rader, Florian 23 January 2010 (has links)
No description available.
290

EVOLUTIONARY OPTIMIZATION OF ATRIAL FIBRILLATION DIAGNOSTIC ALGORITHMS

Smiley, Aref 06 August 2014 (has links)
No description available.

Page generated in 0.0423 seconds