Search results for " wall"

Effect of Streptomycin on Stretch-Induced Change in Myocardial Activation During Ventricular Fibrillation

2008

The aim of this study was to determine whether the changes in myocardial activation pattern resulting from acute stretching during ventricular fibrillation can be counteracted by administering a compound that blocks receptors sensitive to stretch. The study involved 16 isolated rabbit hearts, in which refractoriness and activation frequency during ventricular fibrillation were measured before, during and after localized acute stretching of the left ventricular free wall, either without (series A, n=8) or with (series B, n=8) the presence of streptomycin, 200 micromol. At baseline and during and after stretching, ventricular fibrillation was slower with streptomycin perfusion in series B tha…

Sustained reentry in a 3d regionally ischemic human heart. A simulation study

2016

In this work, we have studied the vulnerable window and propagation patterns in a human heart during acute ischemia. A 3-D biventricular model of a human heart with realistic heterogeneity and fiber orientations has been considered. The ischemic region was located in the anterior left ventricular wall mimicking the occlusion of the circumflex artery. The electrical activity of the tissue was modeled with the monodomain model along with a modified version of the ten Tusscher 2006 ionic model. The model predicts the generation of sustained re-entrant activity in the form of a rotor around the ischemic zone. Patterns in the form of figure-of-eight were also observed within the vulnerable windo…

Echocardiography in myocardial infarction

1986

This paper discusses the usefulness of echocardiography in thrombolysis, its diagnostic value and drawbacks for therapy and the possibilities for follow-up studies. The diagnostic value is seen in the possibility of localizing and defining the extent of myocardial infarction, not only of the left but also of the right ventricle, and recognizing the complications of myocardial infarction as soon as possible 1, 2, 4.

Myoperitoneale Composite Flaps: Ein neues operatives Prinzip zur Vaginalrekonstruktion

1995

In spite of the development of various techniques for the formation of a neovagina, the longterm results are often disappointing, especially if the simpler methods (dilation, ectopic pouch formation, epithelium transfer) have been applied. The more complex surgical techniques such as musculo/fasciocutaneous and colon flaps are associated with a significant risk of severe complications. For certain operative situations necessitating vaginal reconstruction, adequate procedures are still missing. Based on surgico-anatomic investigation of the vascular territories of the myoperitoneal anterior abdominal wall, we introduce the use of myoperitoneal composite flaps from the deep inferior epigastri…

2021

Abstract Background Standard therapy for localised, resectable high risk soft tissue sarcomas consists of wide excision and radiotherapy over several weeks. This treatment schedule is hardly feasible in geriatric and frail patients. In order not to withhold radiotherapy from these patients, hypofractionated radiotherapy with 25 Gy in 5 fractions was evaluated in a geriatric patient population. Patients and methods A retrospective analysis was performed of 18 geriatric patients with resectable high risk soft tissue sarcomas of extremities and thoracic wall. Wound healing and short term oncologic outcome were analysed. In addition, dose constraints for radiotherapy of the extremities were tra…

Modelling cardiac mechanics of left ventricular noncompaction

2020

Left ventricular noncompaction (LVNC) can be defined as a cardiomyopathy characterised by a pattern of prominent trabecular structure and deep intertrabecular recesses, that is thought to be caused by an arrest of normal endomyocardial morphogenesis. Using patient-specific computational modelling, we assessed the cardiac mechanics of five patients with LVNC and compared myocardial stress and pump performance to those of healthy controls. Findings shown that patients with LVNC have impaired left ventricular (LV) function, making it possible that the lack of fibre shortening of noncompacted layer can determine poor heart function. Pronounced end-systolic wall stress on left ventricular wall o…

In vitro evaluation of forces exerted by a new computer-assisted colonoscope (the NeoGuide Endoscopy System).

2006

Background: The NeoGuide Endoscopy System (NES) utilizes a fully articulated, computer-controlled insertion tube that allows proximal segments of the colonoscope to follow the path taken by the tip as it is manually advanced through the colon. The system was designed to eliminate looping and scope displacement during colonoscopy. Material and methods: Using in vitro testing, an inanimate flexible model of the colon incorporating four force transducers located at the key flexure points was employed to measure the axial forces on the colon wall during colonoscopy. In the second part of the study, 10 gastroenterologists performed colonoscopies, using a training latex-based simulator, with the …

Conventional Radiology in the Evaluation of the Small Bowel

2015

For many years, the small bowel has been considered as the “black box” of the gastrointestinal system because it could not be evaluated through endoscopy. For this reason, the conventional radiological methods, such as small bowel enteroclysis and small bowel follow-through, have been considered the standard approach for the evaluation of the small bowel in the diagnosis and management of Crohn’s disease for years. However, due to technological limits, the study of small bowel through conventional radiology has been focused mainly on its function than on its anatomy. To date, the conventional examination with the study of intestinal transit is now rarely used, if not obsolete, but it has st…

Abdominal Muscle Response During Curl-ups on Both Stable and Labile Surfaces

2000

Abstract Background and Purpose. With the current interest in stability training for the injured low back, the use of labile (movable) surfaces, underneath the subject, to challenge the motor control system is becoming more popular. Little is known about the modulating effects of these surfaces on muscle activity. The purpose of this study was to establish the degree of modulating influence of the type of surface (whether stable or labile) on the mechanics of the abdominal wall. In this study, the amplitude of muscle activity together with the way that the muscles coactivated due to the type of surface under the subject were of interest. Subjects. Eight men (mean age=23.3 years [SD=4.3], me…

Diagnostik der trachealen Instabilität: Spiral-CT in Inspiration und Exspiration und respiratorische cine-CT∗

2000

ry Spiral CT and Cine CT. Purpose: In tracheo- and broncho-malacia, localization and determination of collapse is necessary for planning a surgical procedure. We compared inspiratory and spiral CT, cine CT, and bronchoscopy and evaluated the relevance of each method. Methods: Seventeen patients with suspected or verified tracheal stonosis or collapse underwent paired inspiratory and exspiratory spiral CT and cine CT during continuous respiration (temporal increment 100 ms). The tracheal cross-sectional area was calculated and compared. Results : In addition to bronchoscopy, further information concerning localization, extent, collapse, stability of the tracheal wall, distal portions of the …