Utility of continuous wave doppler echocardiography in the noninvasive assessment of left ventricular outflow tract pressure gradient in patients with hypertrophic cardiomyopathy

AbstractSubaortic obstruction is an important determinant of the clinical presentation of and therapeutic approach to patients with hypertrophic cardiomyopathy. Therefore, assessment of the presence and magnitude of the intraventricular pressure gradient is paramount in the clinical evaluation of these patients. To establish the utility of continuous wave Doppler echocardiography in a sessing the pressure gradient in hypertrophic cardiomyopathy, 28 patients representing the wide hemodynamic spectrum of this disease underwent simultaneous determination of the subaortic gradient by continuous wave Doppler ultrasound and cardiac calheterization.With use of the modified Bernoulli equation, the Doppler-estimated gradient showed a strong correlation with the maximal instantaneous pressure difference measured at catheterization, both under basal conditions (r = 0.93; p < 0.0001) and during provocative maneuvers (r = 0.89; p < 0.9001). In 26 of she 28 patients, all assessments of the subaortic gradient were in agreement within 15 mm Hg (average difference 5 ± 3 mm Hg). In the other two patients there were substantial differences between these measurements (under basal conditions in one patient and after provocation in another), although the Doppler technique predicted the presence of marked subaortic obstruction in each. In both patients the erroneous interpretation was due to superimposition of the mitral regurgitation signal on that of left ventricular outflow.Doppler waveforms from the left ventricular outflow tract showed variability in contour among different patients and in individual patients. Hence, continuous wave Doppler echocardiography is a useful noninvasive method for estimating the subaortic gradient in patients with hypertrophic cardiomyopathy. However, technical factors such as contamination of the outflow tract jet with that of mitral regurgitation and variability in waveform configuration may importantly influence such assessments of the subaortic gradient

Coronary-Artery Bypass Surgery in Patients with Ischemic Cardiomyopathy

BACKGROUND: The survival benefit of a strategy of coronary-artery bypass grafting (CABG) added to guideline-directed medical therapy, as compared with medical therapy alone, in patients with coronary artery disease, heart failure, and severe left ventricular systolic dysfunction remains unclear. METHODS: From July 2002 to May 2007, a total of 1212 patients with an ejection fraction of 35% or less and coronary artery disease amenable to CABG were randomly assigned to undergo CABG plus medical therapy (CABG group, 610 patients) or medical therapy alone (medical-therapy group, 602 patients). The primary outcome was death from any cause. Major secondary outcomes included death from cardiovascular causes and death from any cause or hospitalization for cardiovascular causes. The median duration of follow-up, including the current extended-follow-up study, was 9.8 years. RESULTS: A primary outcome event occurred in 359 patients (58.9%) in the CABG group and in 398 patients (66.1%) in the medical-therapy group (hazard ratio with CABG vs. medical therapy, 0.84; 95% confidence interval [CI], 0.73 to 0.97; P=0.02 by log-rank test). A total of 247 patients (40.5%) in the CABG group and 297 patients (49.3%) in the medical-therapy group died from cardiovascular causes (hazard ratio, 0.79; 95% CI, 0.66 to 0.93; P=0.006 by log-rank test). Death from any cause or hospitalization for cardiovascular causes occurred in 467 patients (76.6%) in the CABG group and in 524 patients (87.0%) in the medical-therapy group (hazard ratio, 0.72; 95% CI, 0.64 to 0.82; P CONCLUSIONS: In a cohort of patients with ischemic cardiomyopathy, the rates of death from any cause, death from cardiovascular causes, and death from any cause or hospitalization for cardiovascular causes were significantly lower over 10 years among patients who underwent CABG in addition to receiving medical therapy than among those who received medical therapy alone. (Funded by the National Institutes of Health; STICH [and STICHES] ClinicalTrials.gov number, NCT00023595.)

Propagating Torsion in 3D-Gravity and Dynamical Mass Generation

In this paper, fermions are minimally coupled to 3D-gravity where a dynamical torsion is introduced. A Kalb-Ramond field is non-minimally coupled to these fermions in a gauge-invariant way. We show that a 1-loop mass generation mechanism takes place for both the 2-form gauge field and the torsion. As for the fermions, no mass is dynamically generated: at 1-loop, there is only a mass shift proportional to the Yukawa coupling whenever the fermions have a non-vanishing tree-level mass.Comment: 13 pages, latex file, no figures, some corrections adde

Variability in Ejection Fraction Measured By Echocardiography, Gated Single-Photon Emission Computed Tomography, and Cardiac Magnetic Resonance in Patients With Coronary Artery Disease and Left Ventricular Dysfunction

Importance: Clinical decisions are frequently based on measurement of left ventricular ejection fraction (LVEF). Limited information exists regarding inconsistencies in LVEF measurements when determined by various imaging modalities and the potential impact of such variability. Objective: To determine the intermodality variability of LVEF measured by echocardiography, gated single-photon emission computed tomography (SPECT), and cardiovascular magnetic resonance (CMR) in patients with left ventricular dysfunction. Design, Setting, and Participants: International multicenter diagnostic study with LVEF imaging performed at 127 clinical sites in 26 countries from July 24, 2002, to May 5, 2007, and measured by core laboratories. Secondary study of clinical diagnostic measurements of LVEF in the Surgical Treatment for Ischemic Heart Failure (STICH), a randomized trial to identify the optimal treatment strategy for patients with LVEF of 35% or less and coronary artery disease. Data analysis was conducted from March 19, 2016, to May 29, 2018. Main Outcomes and Measures: At baseline, most patients had an echocardiogram and subsets of patients underwent SPECT and/or CMR. Left ventricular ejection fraction was measured by a core laboratory for each modality independent of the results of other modalities, and measurements were compared among imaging methods using correlation, Bland-Altman plots, and coverage probability methods. Association of LVEF by each method and death was assessed. Results: A total of 2032 patients (mean [SD] age, 60.9 [9.6] years; 1759 [86.6%] male) with baseline LVEF data were included. Correlation of LVEF between modalities was r = 0.601 (for biplane echocardiography and SPECT [n = 385]), r = 0.493 (for biplane echocardiography and CMR [n = 204]), and r = 0.660 (for CMR and SPECT [n = 134]). Bland-Altman plots showed only moderate agreement in LVEF measurements from all 3 core laboratories with no substantial overestimation or underestimation of LVEF by any modality. The percentage of observations that fell within a range of 5% ranged from 43% to 54% between different imaging modalities. Conclusions and Relevance: In this international multicenter study of patients with coronary artery disease and reduced LVEF, there was substantial variation between modalities in LVEF determination by core laboratories. This variability should be considered in clinical management and trial design. Trial Registration: Clinicaltrials.gov Identifier: NCT00023595

The Evolution of the Ammonia Synthesis Catalyst 'AmoMax®-CASALE'

Despite the Haber-Bosch process being more than 100 years old, only incremental improvements have been achieved until recently. Now, by combining the catalyst expertise of CLARIANT and the engineering knowledge of CASALE, a breakthrough has been realized. AmoMax®-Casale is a new ammonia synthesis catalyst jointly developed by Casale and Clariant particularly for use in Casale ammonia converters. AmoMax®-Casale is a customized evolution of the well-known, wustite-based catalyst, AmoMax® 10. While retaining the same superior resistance to ageing, poisoning and mechanical strength, AmoMax®-Casale is significantly more active. This feature allows to reduce the loop recycle rate and the loop pressure and/or to increase the ammonia production. The higher activity of AmoMax®-Casale contributes to improve the overall operating efficiency either by saving energy, or by increasing significantly the plant capacity. This article will describe in detail the successful development of AmoMax®-Casale, explain advantages and commercial benefits based on concrete plant simulations and share the start-up experience of the first commercial reference

Use of Shared Faculty in U.S. and Canadian Dental Schools

Dental schools are facing substantial financial challenges and a shortage of faculty members. One solution to address these issues has been to hire “shared” faculty members, i.e., faculty members whose primary appointment is at one institution who are hired by another institution to teach a course or part of a course. This is a controversial concept. A survey of academic deans at U.S. and Canadian dental schools was conducted for this study; thirty-nine (54 percent) of the seventy-two academic deans completed the online survey. This survey found that the use of shared faculty members is not rare amongst U.S. and Canadian dental schools and that the opinions of the academic deans about the use of shared faculty members ranged widely—from strong support to strong disapproval. Using shared faculty members has advantages and disadvantages for students, the shared faculty members, and both institutions. Many of the disadvantages could be potentially minimized by stakeholders’ working together to develop collaborative arrangements. Networks could be developed in which institutions coordinate hiring of shared faculty members based on what expertise is needed. Financial challenges and shortages of faculty members are unlikely to be resolved in the near future, but use of shared faculty members is one promising approach to begin to meet these challenges