129 research outputs found
Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation
Staphylococcus aureus Bacteraemia in a Tropical Setting: Patient Outcome and Impact of Antibiotic Resistance
Background: Most information on invasive Staphylococcus aureus infections comes from temperate countries. There are considerable knowledge gaps in epidemiology, treatment, drug resistance and outcome of invasive S. aureus infection in the tropics. Methods: A prospective, observational study of S. aureus bacteraemia was conducted in a 1000-bed regional hospital in northeast Thailand over 1 year. Detailed clinical data were collected and final outcomes determined at 12 weeks, and correlated with antimicrobial susceptibility profiles of infecting isolates. Principal Findings: Ninety-eight patients with S. aureus bacteraemia were recruited. The range of clinical manifestations was similar to that reported from temperate countries. The prevalence of endocarditis was 14%. The disease burden was highest at both extremes of age, whilst mortality increased with age. The all-cause mortality rate was 52%, with a mortality attributable to S. aureus of 44%. Methicillin-resistant S. aureus (MRSA) was responsible for 28% of infections, all of which were healthcare-associated. Mortality rates for MRSA and methicillin-susceptible S. aureus (MSSA) were 67% (18/27) and 46% (33/71), respectively (p = 0.11). MRSA isolates were multidrug resistant. Only vancomycin or fusidic acid would be suitable as empirical treatment options for suspected MRSA infection. Conclusions: S. aureus is a significant pathogen in northeast Thailand, with comparable clinical manifestations and a similar endocarditis prevalence but higher mortality than industrialised countries. S. aureus bacteraemia is frequently associated with exposure to healthcare settings with MRSA causing a considerable burden of disease. Further studies are required to define setting-specific strategies to reduce mortality from S. aureus bacteraemia, prevent MRSA transmission, and to define the burden of S. aureus disease and emergence of drug resistance throughout the developing world. © 2009 Nickerson et al
Moving Beyond Mimicry: Developing Hybrid Spaces in Indian Business Schools
This article analyses the identity work of Indian management educators and scholars as they seek to establish, maintain and revise a sense of self in the context of business school globalization. We show how globalization, combined with the historical legacy of colonialism, renders Indian scholars precarious in their interactions with Western business schools. Based on a qualitative interview study, we explore how Indian business school scholars perform their identities in the context of neo-colonial relations, which are characterised by the dominance of English language and a pressure to conform to research norms set by globally-ranked journals. Drawing on postcolonial theory, our argument focuses on mimicry as a distinctive form of identity work that involves maintaining difference between Western and non-Western identities by 'Othering' Indian scholars, while simultaneously seeking to transform them. We draw attention to ambivalence within participants' accounts, which we suggest arises because the authority of Western scholarship relies on maintaining non-Western scholars in a position of alterity or 'not quite-ness'. We suggest that hybridity offers an opportunity to disrupt and question current practices of business school globalization and facilitate scholarly engagement that reflects more diverse philosophical positions and worldviews
Aortic stiffness in aortic stenosis assessed by cardiovascular MRI: a comparison between bicuspid and tricuspid valves
Objectives
To compare aortic size and stiffness parameters on MRI between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients with aortic stenosis (AS).
Methods
MRI was performed in 174 patients with asymptomatic moderate-severe AS (mean AVAI 0.57 ± 0.14 cm2/m2) and 23 controls on 3T scanners. Valve morphology was available/analysable in 169 patients: 63 BAV (41 type-I, 22 type-II) and 106 TAV. Aortic cross-sectional areas were measured at the level of the pulmonary artery bifurcation. The ascending and descending aorta (AA, DA) distensibility, and pulse wave velocity (PWV) around the aortic arch were calculated.
Results
The AA and DA areas were lower in the controls, with no difference in DA distensibility or PWV, but slightly lower AA distensibility than in the patient group. With increasing age, there was a decrease in distensibility and an increase in PWV. After correcting for age, the AA maximum cross-sectional area was higher in bicuspid vs. tricuspid patients (12.97 [11.10, 15.59] vs. 10.06 [8.57, 12.04] cm2, p < 0.001), but there were no significant differences in AA distensibility (p = 0.099), DA distensibility (p = 0.498) or PWV (p = 0.235). Patients with BAV type-II valves demonstrated a significantly higher AA distensibility and lower PWV compared to type-I, despite a trend towards higher AA area.
Conclusions
In patients with significant AS, BAV patients do not have increased aortic stiffness compared to those with TAV despite increased ascending aortic dimensions. Those with type-II BAV have less aortic stiffness despite greater dimensions. These results demonstrate a dissociation between aortic dilatation and stiffness and suggest that altered flow patterns may play a role.
Key Points
• Both cellular abnormalities secondary to genetic differences and abnormal flow patterns have been implicated in the pathophysiology of aortic dilatation and increased vascular complications associated with bicuspid aortic valves (BAV).
• We demonstrate an increased ascending aortic size in patients with BAV and moderate to severe AS compared to TAV and controls, but no difference in aortic stiffness parameters, therefore suggesting a dissociation between dilatation and stiffness.
• Sub-group analysis showed greater aortic size but lower stiffness parameters in those with BAV type-II AS compared to BAV type-I
Duality and fallibility in practices of the self: The 'inclusive subject’ in diversity training
The concept of ‘inclusion’ has been gaining ground in a field known as equality and diversity work. Scholars have begun to both theorise what this concept means as a normative goal and to critically examine how it is mobilised in organisational practice. This paper contributes to the latter conversation by asking what comes to count as ‘doing inclusion’ at the level of the individual. I examine the practices of diversity training in United Kingdom organisations, in which diversity practitioners seek to transform their trainees into people who will act inclusively toward others, asking: Who is the ‘inclusive subject’ that is being constructed – imagined, sought and legitimised – through diversity training? What are the conditions of possibility that shape the emergence of this subject? And what are the possibilities that this subject affords to marginalised groups struggling for recognition within organisations? The analysis mobilises Foucault’s notions of power/knowledge, discipline, and practices of the self to describe and discuss the performance of inclusive subjectivity in the context of diversity training in the UK. The practices described are found to be facilitated by two key forms of knowledge about how the subject is characterised: duality and fallibility. The discussion of these two forms of knowledge leads us to consider the relations of both discipline and freedom that take place in diversity training.</p
The Chemical and Isotopic Record of Rock-Water Interaction in the Sherman Granite, Wyoming and Colorado
Clinical outcome of degenerative mitral regurgitation critical importance of echocardiographic quantitative assessment in routine practice
BACKGROUND: Echocardiographic quantitation of degenerative mitral regurgitation (DMR) is recommended whenever possible in clinical guidelines but is criticized and its scalability to routine clinical practice doubted. We hypothesized that echocardiographic DMR quantitation, performed in routine clinical practice by multiple practitioners, predicts independently long-term survival and thus is essential to DMR management. METHODS: We included patients diagnosed with isolated mitral valve prolapse from 2003 to 2011 and any degree of mitral regurgitation quantified by any physician/sonographer in routine clinical practice. Clinical/echocardiographic data acquired at diagnosis were retrieved electronically. The end point was mortality under medical treatment analyzed by Kaplan-Meier method and proportional hazard models. RESULTS: The cohort included 3914 patients (55% male) mean age (\ub1standard deviation) 62\ub117 years with left ventricular ejection fraction 63\ub18% and median after routinely-measured effective regurgitant orifice area (EROA) [interquartile range], 19 [0-40] mm2. During follow-up (6.7\ub13.1 years), 696 patients died under medical management, and 1263 underwent mitral surgery. In multivariate analysis, routinely-measured EROA was associated with mortality (adjusted hazard ratio, 1.19; 95% confidence interval, 1.13-1.24; P<0.0001 per 10 mm2) independently of left ventricular ejection fraction and end-systolic diameter, symptoms, and age/comorbidities. The association between routinely-measured EROA and mortality persisted with competitive risk modeling (adjusted hazard ratio, 1.15; 95% confidence interval, 1.10-1.20; P<0.0001 per 10 mm2), or in patients without guideline-based class I/II surgical triggers (adjusted hazard ratio, 1.19; 95% confidence interval, 1.10-1.28; P<0.0001 per 10 mm2) and in all subgroups examined (all P<0.01). Spline curve analysis showed that, compared with general population mortality, excess mortality appears for moderate DMR (EROA 6520 mm2), becomes notable at EROA 6530 mm2, and steadily increases with higher EROA levels (eg, higher EROA levels beyond the 40 mm2 threshold). CONCLUSIONS: Echocardiographic DMR quantitation is scalable to routine practice and is independently associated with clinical outcome. Routinely-measured EROA is strongly associated with long-term survival under medical treatment. Excess mortality versus the general population appears in the moderate DMR range and steadily increases with higher EROA. Hence, individual EROA values should be integrated into therapeutic considerations, in addition to categorical DMR grading
Outcome and undertreatment of mitral regurgitation: a community cohort study
Background: Mitral regurgitation is the most common valve disease worldwide but whether the community-wide prevalence, poor patient outcomes, and low rates of surgical treatment justify costly development of new therapeutic interventions remains uncertain. Therefore, we did an observational cohort study to assess the clinical characteristics, outcomes, and degree of undertreatment of mitral regurgitation in a community setting.
Methods: We used data from Mayo Clinic electronic health records and the Rochester Epidemiology Project to identify all cases of moderate or severe isolated single-valvular mitral regurgitation (with no other severe left-sided valvular disease or previous mitral surgery) diagnosed during a 10-year period in the community setting in Olmsted County (MN, USA). We assessed clinical characteristics, mortality, heart failure incidence, and results of cardiac surgery post-diagnosis.
Findings: Between Jan 1, 2000, and Dec 31, 2010, 1294 community residents (median age at diagnosis 77 years [IQR 66–84]) were diagnosed with moderate or severe mitral regurgitation by Doppler echocardiography (prevalence 0·46% [95% CI 0·42–0·49] overall; 0·59% [0·54–0·64] in adults). Left-ventricular ejection fraction below 50% was frequent (recorded in 538 [42%] patients), and these patients had a slightly lower regurgitant volume than those with an ejection fraction of 50% or higher (mean 39 mL [SD 16] vs 45 mL [21], p<0·0001). Post-diagnosis mortality was mainly cardiovascular in nature (in 420 [51%] of 824 patients for whom the cause of death was available) and higher than expected for residents of the county for age or sex (risk ratio [RR] 2·23 [95% CI 2·06–2·41], p<0·0001). This excess mortality affected all subsets of patients, whether they had a left-ventricular ejection fraction lower than 50% (RR 3·17 [95% CI 2·84–3·53], p<0·0001) or of 50% or higher (1·71 [1·53 −1·91], p<0·0001) and with primary mitral regurgitation (RR 1·73 [95% CI 1·53–1·96], p<0·0001) or secondary mitral regurgitation (2·72 [2·48–3·01], p<0·0001). Even patients with a low comorbidity burden combined with favourable characteristics such as left-ventricular ejection fraction of 50% or higher (RR 1·28 [95% CI 1·10–1·50], p<0·0017) or primary mitral regurgitation (1·29 [1·09–1·52], p=0·0030) incurred excess mortality. Heart failure was frequent (mean 64% [SE 1] at 5 years postdiagnosis), even in patients with left-ventricular ejection fraction of 50% or higher (49% [2] at 5 years postdiagnosis) or in those with primary mitral regurgitation (48% [2]). Mitral surgery was ultimately done in only 198 (15%) of 1294 patients, of which the predominant type of surgery was valve repair (in 149 [75%] patients). Mitral surgery was done in 28 (5%) of 538 patients with left-ventricular ejection fraction below 50% and in 170 (22%) of 756 patients with ejection fraction of 50% or higher, and in 34 (5%) of 723 with secondary mitral regurgitation versus 164 (29%) of 571 with primary regurgitation. All other types of cardiac surgery combined were performed in only 3% more patients (237 [18%] patients) than the number who underwent mitral surgery.
Interpretation: In the community, isolated mitral regurgitation is common and is associated with excess mortality and frequent heart failure postdiagnosis in all patient subsets, even in those with normal left-ventricular ejection fraction and low comorbidity. Despite these poor outcomes, only a minority of affected patients undergo mitral (or any type of cardiac) surgery even in a community with all means of diagnosis and treatment readily available and accessible. This suggests that in a wider population there might be a substantial unmet need for treatment for this disorder
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