Search results for "FLOW OBSTRUCTION"
showing 10 items of 12 documents
Quantitative analysis of airway obstruction in lymphangioleiomyomatosis
2020
Lymphangioleiomyomatosis (LAM) is a rare, cystic lung disease with progressive pulmonary function loss caused by progressively proliferating LAM cells. The degree of airway obstruction has not been well investigated within the pathogenesis of LAM. Using a combination of ex vivo computed tomography (CT), microCT and histology, the site and nature of airway obstruction in LAM explant lungs was compared with matched control lungs (n=5 each). The total number of airways per generation, total airway counts, terminal bronchioles number and surface density were compared in LAM versus control. Ex vivo CT analysis demonstrated a reduced number of airways from generation 7 on (p<0.0001) in LAM compar…
Simulation of left ventricular outflow tract (LVOT) obstruction in transcatheter mitral valve-in-ring replacement.
2020
Left ventricular outflow tract (LVOT) obstruction is a feared complication of transcatheter mitral valve replacement (TMVR). This procedure leads to an elongation of LVOT in the left ventricle (namely, the neoLVOT), ultimately portending hemodynamic impairment and death. This study sought to understand the biomechanical implications of LVOT obstruction in two patients who underwent TMVR as an "off-label" application of the Edwards SAPIEN 3 (S3) Ultra transcatheter heart valve (THV). A computational framework of TMVR was developed to assess the neoLVOT area and quantify the sub-aortic flow structure. We observed that the annuloplasty ring serves as the key anchor zone of S3 Ultra THV. A good…
Numerical simulation of transcatheter mitral valve replacement: The dynamic implication of LVOT obstruction in the valve-in-ring case.
2022
Transcatheter mitral valve replacement (TMVR) has been used for “off-label” treatment when annuloplasty band ring for mitral repair fails. However, the complex anatomy and function of the mitral valve may lead to fatal complications as a result of the left ventricular outflow tract (LVOT) obstruction in TMVR. We report the structural and hemodynamic response of LVOT obstruction resulting from TMVR with the Edwards SAPIEN 3 Ultra (S3) device. We modified the original Living Heart Human Model (LHHM) to account for a failed mitral valve with an annuloplasty band ring and simulated the cardiac beating condition in the setting of S3 device implantation. Findings demonstrated a high dynamic behav…
GOLD and the fixed ratio
2012
We thank Dr Vestbo for his interest in our manuscript “Diagnosis of airway obstruction in the elderly: contribution of the SARA study” and for the opportunity to clarify some points. As mentioned in the title and aims, the intent of the paper is to offer a contribution to the open issue of identification of airway obstruction in elderly people.1 We agree with Dr Vestbo about the utility of distinguishing between the clinical and functional aspects of chronic obstructive pulmonary disease (COPD). We stress that, until the term COPD is used, diagnosis needs clinical evidence of a chronic pulmonary disease and functional evidence of airway obstruction. Given that symptoms compatible with COPD …
The geriatric asthma: pitfalls and challenges
2016
Historically, asthma has been envisioned as a disease of younger ages. This has led to the assumption that respiratory symptoms suggestive of asthma occurring in older ages are to be attributed to conditions other than asthma, mainly COPD. Old observational reports and new epidemiological studies confirm that asthma is as frequent in older as it is in younger populations. Nevertheless, under-recognition, misdiagnosis and under-treatment are still relevant issues. The characterization of asthma in the aged suffers from the fact that there has been very little original research in this field. Indeed, geriatric asthma is often excluded from clinical trials because of age and comorbidities. The…
Spirometric criteria to diagnose airway obstruction in the elderly: fixed ratio vs. lower limit of normal.
2015
COPD is the most common chronic lung disease. It becomes more prevalent with increasing age but remains under-diagnosed in the elderly. A heated debate concerns the most suitable way to diagnose airway obstruction in this age group. Most COPD guidelines recommend to use a FEV1/FVC of 0.70 as threshold to define an obstructive ventilatory defect. While the use of a 0.70 ratio may be simple, it may result in under-diagnosis of airflow obstruction in young people and over-diagnosis in the elderly due to an age-related decline in pulmonary volumes, especially in FEV1. This might lead to unnecessary use of medications and increased risk of adverse effects. A proposed strategy for reducing the mi…
Similarity and differences in elderly patients with fixed airflow obstruction by asthma and by chronic obstructive pulmonary disease
2008
SummaryBackgroundEpidemiologic studies have demonstrated that elderly patients with fixed airflow obstruction can be affected by asthma or chronic obstructive pulmonary disease (COPD).MethodsWe studied 49 consecutive elderly outpatients, presenting fixed airflow obstruction, by clinical history (smoking), pulmonary function tests, blood gas analysis, and induced sputum.ResultsThe age was not different in patients with COPD (n=28) and asthma (n=21) (70.2±3.9 years vs. 69.6±3.7 years), also the degree of fixed airflow obstruction was similar (FEV1: 58.3±1.5% vs. 59.0±1.4% of predicted). Patients with asthma had significantly more eosinophils in peripheral blood (0.43±0.05×10−3μL vs. 0.27±0.1×…
Direct measurement of left ventricular outflow tract by transthoracic real-time 3D-echocardiography increases accuracy in assessment of aortic valve …
2007
Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter.We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from …
Agreement in Asthmatics' Perception of Dyspnea During Acute and Chronic Obstruction
2005
Objective Three types of asthmatic patients can be identified during periods of clinical stability: “poor perceivers,” “normal perceivers,” and “over perceivers.” When asthmatics undergo bronchial challenge in the laboratory, the same distinctions in type of perception can be observed. The aim of the present study was to determine the level of agreement between the 2 situations. Patients and methods A total of 93 patients with persistent moderate asthma (36 men and 57 women; mean age 40 years) were studied. We asked them to assess their dyspnea on a modified Borg scale when stable and after each histamine dose in a bronchial provocation test. When a patient's Borg scale assessment in stable…
Bronchial thermoplasty in severe asthma: food for thoughts
2014
Asthma is a complex inflammatory disorder of the airways characterized by airway hyper-responsiveness and variable, reversible, airflow obstruction. Bronchial thermoplasty (BT) is a new modality for treating asthma. It targets airway smooth muscles (ASM) by delivering a controlled specific amount of thermal energy (radiofrequency ablation) to the airway wall through a dedicated catheter. The use of bronchial thermoplasty has been widely discussed for its potential in the treatment of asthma, since it seems to be able to reduce the symptoms of asthma. The definitive study for BT (AIR2 trial) employed a randomized, double-blind, sham-controlled design and enrolled 288 subjects with severe per…