B-type natriuretic levels in critically ill patients: critically misleading?

Although B-type natriuretic peptide (BNP) has been used for the diagnosis of congestive heart failure in many clinical settings, its diagnostic role in critically ill patients remains uncertain. The body of literature suggests that BNP and N-terminal pro-BNP levels are not useful for the diagnosis of systolic or diastolic heart failure in the critically ill, including in patients with brain hemorrhage, due to poor specificity. However, these cardiac peptides may have a more promising prognostic role in this patient population

Computational Insights into Sulfur Redox Chemistry in Enzymology

In biochemistry, sulfur-containing biomolecules enrich the chemical diversity in cells. This occurs via their participation in several reactions including disulfide formation, metal-binding and redox catalysis. Since sulfur occurs in various oxidation states, it exhibits interesting chemistry and reactivity. In this Dissertation computational modeling techniques have been used to investigate several aspects of sulfur\u27s unique chemistry. Particularly, previously proposed mechanisms for sulfenic acids formation and reduction/overoxidation pathways have been examined In detail. A holistic picture of sulfur/sulfenic acid chemistry in biochemistry has been portrayed. For instance, the importance of non-covalent interaction in stabilizing the unstable sulfenic acid intermediates has been highlighted. Furthermore, the mechanism of Thiol activation in several active sites as well as the factors affecting thiolate stabilization has been determined in several enzymes. The role of protein dynamics and possible effects on catalysis has been emphasized. Moreover, a novel antioxidant pathway has been proposed. Computationally, the effect of choosing starting structure for modelling was also stressed

Left Atrial Deformation Predicts Pulmonary Capillary Wedge Pressure in Pediatric Heart Transplant Recipients

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110826/1/echo12679.pd

Randomized controlled trial of influenza vaccine in patients with heart failure to reduce adverse vascular events (IVVE): Rationale and design

Background: Influenza is associated with an increase in the risk of cardiac and other vascular events. Observational data and small randomized trials suggest that influenza vaccination may reduce such adverse vascular events. Research Design and Methods: In a randomized controlled trial patients with heart failure are randomized to receive either inactivated influenza vaccine or placebo annually for 3 years. Patients aged ≥18 years with a clinical diagnosis of heart failure and NYHA functional class II, III and IV are eligible. Five thousand patients from 10 countries where influenza vaccination is not common (Asia, the Middle East, and Africa) have been enrolled. The primary outcome is a composite of the following: cardiovascular death, non-fatal myocardial infarction, non-fatal stroke and hospitalizations for heart failure using standardized criteria. Analyses will be based on comparing event rates between influenza vaccine and control groups and will include time to event, rate comparisons using Poisson methods, and logistic regression. The analysis will be conducted by intention to treat i.e. patients will be analyzed in the group in which they were assigned. Multivariable secondary analyses to assess whether variables such as age, sex, seasonality modify the benefits of vaccination are also planned for the primary outcome. Conclusion: This is the largest randomized trial to test if influenza vaccine compared to control reduces adverse vascular events in high risk individuals

Estimation of LV End‐Diastolic Pressure Using Color‐TDI and Its Application to Noninvasive Quantification of Myocardial Wall Stress

Background: This study was undertaken to evaluate early-diastolic annular velocity (Ea) by color-TDI, combined with the early transmitral filling velocity (E) by pulsed Doppler echocardiographyfor estimation of left ventricular end diastolic pressure (LVEDP). We applied LVEDP to noninvasivequantification of myocardial wall stress in end-diastole. Forty-one coronary artery disease (CAD)patients with sinus rhythm underwent echocardiography and cardiac catheterization evaluated inthe study. Methods: First linear regression analysis was performed to assess the relationships betweenE/Ea and LVEDP. Second LVEDP estimation with these two methods was tested prospectively in 59additional CAD patients, and average end-diastolic wall stress was calculated at rest by measuringthe principal radii, the thickness of the LV segments, and the estimated LVEDP. The results werecompared to the wall stress that was calculated using catheter-measured LVEDP. Linear regressionanalysis was performed to assess the relationships between calculated wall stress using Doppler-estimated LVEDP (WSEP) and calculated wall stress using catheter-measured LVEDP (WSMP).Results: The results showed that LVEDP had a strong correlation to the lateral E/Ea (r = 0.85; P <0.001) and medial E/Ea ratios (r = 0.73; P < 0.001). No significant differences were found between theWSEP and WSMP. There were highly significant correlations (at least r = 0.85, P < 0.001) betweenthe WSMP and WSEP at all the myocardial sites. Conclusions: The current data demonstrate thatthe lateral E/Ea ratio obtained by Doppler echocardiography and color-TDI is a powerful estimator ofLVEDP in CAD patients and provides pressure information required for noninvasive quantificationof LV myocardial wall stress with reasonable accuracy in diastole. (ECHOCARDIOGRAPHY, Volume26, April 2009

Mitral annular myocardial velocity assessment of segmental left ventricular diastolic function after prolonged exercise in humans

This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @ 2005 The Physiological society.We assessed segmental and global left ventricular (LV) diastolic function via tissue-Doppler imaging (TDI) as well as Doppler flow variables before and after a marathon race to extend our knowledge of exercise-induced changes in cardiac function. Twenty-nine subjects (age 18–62 year) volunteered to participate and were assessed pre- and post-race. Measurements of longitudinal plane TDI myocardial diastolic velocities at five sites on the mitral annulus included peak early myocardial tissue velocity (E′), peak late (or atrial) myocardial tissue velocity (A′) and the ratio E′/A′. Standard pulsed-wave Doppler transmitral and pulmonary vein flow indices were also recorded along with measurements of body mass, heart rate, blood pressures and cardiac troponin T (cTnT), a biomarker of myocyte damage. Pre- to post-race changes in LV diastolic function were analysed by repeated measures ANOVA. Delta scores for LV diastolic function were correlated with each other and alterations in indices of LV loading. Diastolic longitudinal segmental and mean TDI data were altered post-race such that the mean E′/A′ ratio was significantly depressed (1.51 ± 0.34 to 1.16 ± 0.35, P < 0.05). Changes in segmental and global TDI data were not related to an elevated post-race HR, a decreased post-race pre-load or an elevated cTnT. The pulsed wave Doppler ratio of peak early transmitral flow velocity (E)/peak late (or atrial) flow velocity (A) was also significantly reduced post-race (1.75 ± 0.46 to 1.05 ± 0.30, P < 0.05); however, it was significantly correlated with post-race changes in heart rate. The lack of change in E/E′ from pre- to post-race (3.4 ± 0.8 and 3.3 ± 0.7, respectively) suggests that the depression in diastolic function is likely to be due to altered relaxation of the left ventricle; however, the exact aetiology of this change remains to be determined