Influence of left bundle branch block on left ventricular volumes, ejection fraction and regional wall motion

Background. Left ventricular volumes, ejection fraction and regional wall motion are cardiac parameters which provide valuable information for patient management in a large variety of cardiac conditions. Differences in regional wall motion are of relevance in the field of cardiac resynchronisation therapy. We quantified three-dimensional echocardiographic measurements of left ventricular volumes, ejection and regional wall motion (e.g. expressed as systolic dyssynchrony index (SDI)) in two patient cohorts: patients with normal conduction and patients with complete left bundle branch block. Methods. Thirty-five patients scheduled for routine cardiac examination underwent three-dimensional echocardiography: 23 patients with normal conduction and 12 patients with a complete left bundle branch block. Full-volume datasets were analysed and end-systolic volume (ESV), end-diastolic volume (EDV) and ejection fraction (EF) were obtained. SDI was derived from the standard deviation of the measured times to reach minimal regional volume for each of the 16 segments of the left ventricle. Results. A significant difference was observed in left ventricular volumes, ejection fraction and SDI between the two groups. Patients with complete left bundle branch block showed higher EDV (p=0.025) and ESV (p<0.01) and a lower EF (p<0.01) than patients with normal conduction. SDI is significantly higher in patients with complete left bundle branch block (p=0.004) expressing a higher amount of ventricular dyssynchrony. Intraobserver variability showed excellent correlation coefficients: r=0.99 for EDV, ESV and SDI and r=0.98 for EF. Conclusion. Three-dimensional echocardiography is a feasible and reproducible method for the quantification of left ventricular volumes, left ventricular ejection fraction and regional wall motion. Differences can be assessed between normal patients and patients with left bundle branch block. (Neth Heart J 2007;15:89-94.)     

Radionuclide angiocardiography,a noninvasive method for evaluating left ventricular ejection fraction and regional wall motion; comparison with contrast left ventricular angiography.

The efficacy of gated synchronous acquisition (GSA) after cardiac blood pool labelling in assessing left ventricular function (ejection fraction and regional wall motion) was evaluated in 31 patients within 24 hours of contrast left ventricular angiography. With the R-wave of the electrocardiogram as a physiologic marker, radionuclide data recorded into an on-line computer allowed construction of cardiac blood pool images during sequential periods of the cardiac cycle. The images, of high count density, have good spatial resolution and can be viewed repetitively in real time in a cine mode. The ejection fractions calculated from the left ventricular time-activity curves corrected for background activity correlated well with the ejection fractions determined from dimension analysis of the contrast left ventricular angiograms (r = 0.87). The results were highly reproducible (r = 0.97). Results of analysis of left ventricular wall motion were similar with the two types of angiograms in 26 of the 31 subjects. GSA is a simple, safe means of evaluating left ventricular ejection fraction and regional wall motion noninvasively.     

Impact of left ventricular ejection fraction on the results of cardiac rehabilitation

Netherlands Heart Journal -     

Evaluation and classification of right ventricular wall motion abnormalities in healthy subjects by 3-tesla cardiovascular magnetic resonance imaging

Background

Right ventricular (RV) shape and function serves as an indicator in several types of heart disease such as arrhythmogenic right ventricular dysplasia (ARVD). However, there is no in-depth knowledge of RV motion, even in healthy subjects. The aim of our study was to provide a quantitative analysis of normal variations in RV wall motion in healthy subjects by cardiac magnetic resonance imaging (CMRI).

Material and methods

The study population consisted of 65 consecutive patients referred for the evaluation of cardiac function by 3 Tesla CMR. Balanced steady-state free-precession images were obtained and areas of disordered RV wall motion were evaluated and classified based on a standardised segmental model for the right ventricle.

Results

In 59 patients (90.8 %) wall motion abnormalities (WMA) of the right ventricle were evident. WMA were predominately detected in the apicolateral segments (72 %) compared with mediolateral (24 %, P < 0.001) and inferolateral segments (4 %, P < 0.001). Dyskinesia was the most frequent wall motion disorder (62.4 %), followed by hypokinesia (20.8 %) and bulging (16.8 %). The mean WMA diameter in the transverse plane (6.4 ± 1.9 mm) was significantly shorter compared with the diameter in the horizontal long-axis (8.1 ± 3.6 mm, P = 0.002) and short-axis plane (10.7 ± 4.6 mm).

Conclusion

WMA of the right ventricle are common. Therefore, one should be aware that these nonpathological wall motion disorders can easily be mistaken for a pathological regional wall motion contraction, particularly in ARVD where to date, clear wall motion criteria are lacking.     

Computer-assisted determination of left ventricular endocardial borders reduces variability in the echocardiographic assessment of ejection fraction

Background

Left ventricular size and function are important prognostic factors in heart disease. Their measurement is the most frequent reason for sending patients to the echo lab. These measurements have important implications for therapy but are sensitive to the skill of the operator. Earlier automated echo-based methods have not become widely used. The aim of our study was to evaluate an automatic echocardiographic method (with manual correction if needed) for determining left ventricular ejection fraction (LVEF) based on an active appearance model of the left ventricle (syngo^®AutoEF, Siemens Medical Solutions). Comparisons were made with manual planimetry (manual Simpson), visual assessment and automatically determined LVEF from quantitative myocardial gated single photon emission computed tomography (SPECT).

Methods

60 consecutive patients referred for myocardial perfusion imaging (MPI) were included in the study. Two-dimensional echocardiography was performed within one hour of MPI at rest. Image quality did not constitute an exclusion criterion. Analysis was performed by five experienced observers and by two novices.

Results

LVEF (%), end-diastolic and end-systolic volume/BSA (ml/m²) were for uncorrected AutoEF 54 ± 10, 51 ± 16, 24 ± 13, for corrected AutoEF 53 ± 10, 53 ± 18, 26 ± 14, for manual Simpson 51 ± 11, 56 ± 20, 28 ± 15, and for MPI 52 ± 12, 67 ± 26, 35 ± 23. The required time for analysis was significantly different for all four echocardiographic methods and was for uncorrected AutoEF 79 ± 5 s, for corrected AutoEF 159 ± 46 s, for manual Simpson 177 ± 66 s, and for visual assessment 33 ± 14 s. Compared with the expert manual Simpson, limits of agreement for novice corrected AutoEF was lower than for novice manual Simpson (0.8 ± 10.5 vs. -3.2 ± 11.4 LVEF percentage points). Calculated for experts and with LVEF (%) categorized into < 30, 30–44, 45–54 and ≥ 55, kappa measure of agreement was moderate (0.44–0.53) for all method comparisons (uncorrected AutoEF not evaluated).

Conclusion

Corrected AutoEF reduces the variation in measurements compared with manual planimetry, without increasing the time required. The method seems especially suited for unexperienced readers.     

Contraction-relaxation coupling mechanism characterization in the thermodynamic phase plane: normal vs. impaired left ventricular ejection fraction.

Using simultaneous pressure-volume measurements obtained during cardiac catheterization, we employ the thermodynamic phase-plane (TPP) method to characterize global contraction-relaxation coupling (CRC) between normal and impaired left ventricular (LV) ejection fraction (LVEF) groups. The cardiac cycle inscribes a closed loop in the TPP defined by the coordinates "potential" power [V(dP/dt), ergs/s] and "kinetic" power [P(dV/dt), ergs/s]. The TPP-derived indexes kappa and rho define the chamber's contractile and CRC attributes, respectively. Data from 33 subjects dichotomized as normal control (n = 22, >50% LVEF) and impaired LVEF (n = 11, <50% LVEF) were analyzed. The results were as follows: kappa = 3.0 +/- 1.1 and rho = -0.38 +/- 0.21 for controls and kappa = 5.4 +/- 1.6 and rho = -1.14 +/- 0.47 for the impaired LVEF group; kappa and rho are significantly higher for impaired LVEF than for control (P < 0.001 for both). As kappa increased, rho decreased (r = -0.69) for all subjects. Hence, ventricles with impaired LVEF are thermodynamically less efficient because they require more potential power per unit of delivered kinetic power than controls. We conclude that TPP-derived indexes of CRC facilitate assessment of chamber efficiency in thermodynamic terms and elucidate the dominant differentiating features in terms of CRC indexes.     

NF-RCNN: Heart localization and right ventricle wall motion abnormality detection in cardiac MRI

Convolutional neural networks (CNNs) are extensively used in cardiac image analysis. However, heart localization has become a prerequisite to these networks since it decreases the size of input images. Accordingly, recent CNNs benefit from deeper architectures in gaining abstract semantic information. In the present study, a deep learning-based method was developed for heart localization in cardiac MR images. Further, Network in Network (NIN) was used as the region proposal network (RPN) of the faster R-CNN, and then NIN Faster-RCNN (NF-RCNN) was proposed. NIN architecture is formed based on “MLPCONV” layer, a combination of convolutional network and multilayer perceptron (MLP). Therefore, it could deal with the complicated structures of MR images. Furthermore, two sets of cardiac MRI dataset were used to evaluate the network, and all the evaluation metrics indicated an absolute superiority of the proposed network over all related networks. In addition, FROC curve, precision-recall (PR) analysis, and mean localization error were employed to evaluate the proposed network. In brief, the results included an AUC value of 0.98 for FROC curve, a mean average precision of 0.96 for precision-recall curve, and a mean localization error of 6.17 mm. Moreover, a deep learning-based approach for the right ventricle wall motion analysis (WMA) was performed on the first dataset and the effect of the heart localization on this algorithm was studied. The results revealed that NF-RCNN increased the speed and decreased the required memory significantly.     

Lipogenic capacity and relative contribution of the different tissues and organs to lipid synthesis in male rat

The rates of 3H2O incorporation into total lipids and fatty acids were measured in vivo in the different organs and tissues of 7-week old male Wistar rats to compare the lipogenic capacity of those organs and tissues and to determine their relative contributions to body lipid synthesis. Our results were the following; (1) liver was the major site of the synthesis of total lipids and fatty acids (37 and 42%, respectively, of body synthesis); (2) white adipose tissues synthesized about 24% of the total lipids; mesenteric adipose tissue alone synthesizing 40% of the fatty acids produced in dissectable white adipose tissues; (3) skin showed low lipid synthesis but played an appreciable role in that synthesis (8% of the total) due to its large contribution to total body weight; (4) other organs (excluding liver) showed low lipid synthesis; however, that of the small intestine was 1-2% of body synthesis; (5) the rest of the carcass (mainly musculature and skeleton) contributed 25% to body lipid synthesis. The putative roles of the different tissues and organs in adipose tissue development have been discussed.     

Quantification of corruption in preventative cost-based S-LCA: a contribution to the Oiconomy project

The International Journal of Life Cycle Assessment - Corruption is one of the key social aspects, heavily impacting all three Planet-, People- and Prosperity sustainability pillars and is therefore...     

How to diagnose heart failure with preserved ejection fraction: the value of invasive stress testing

Heart failure with preserved ejection fraction (HFpEF) is a growing healthcare burden worldwide and its prevalence is increasing. Diagnosing HFpEF is challenging and relies upon the presence of symptoms and/or signs of heart failure, preserved left ventricular systolic function, and evidence of diastolic dysfunction. Current diagnostic algorithms mainly rely on echocardiography (E/e’) and biomarkers (NT-proBNP). However, only a minority of patients with HFpEF are identified, and especially HFpEF patients at an early stage of the disease are easily missed. We propose to incorporate invasive stress testing, by means of right heart catheterisation at rest and during exercise, and accurate assessment of right ventricular function, by means of cardiac magnetic resonance imaging. These additions to the current diagnostic work-up will improve diagnostic sensitivity and accurate staging of HFpEF patients.     

Estimation of the recombination fraction by the maximum likelihood method in mapping interacting genes relative to marker loci

For mapping nonlinked interacting genes relative to marker loci, the recombination fractions can be calculated by using the log-likelihood functions were derived that permit estimation of recombinant fractions by solving the ML equations on the basis of F2 data at various types of interaction. In some cases, the recombinant fraction estimates are obtained in the analytical form while in others they are numerically calculated from concrete experimental data. With the same type of epistasis the log-functions were shown to differ depending on the functional role (suppression or epistasis) of the mapped gene. Methods for testing the correspondence of the model and the recombination fraction estimates to the experimental data are discussed. In ambiguous cases, analysis of the linked marker behavior makes it possible to differentiate gene interaction from distorted single-locus segregation, which at some forms of interaction imitate phenotypic ratios.     

Endovascular renal sympathetic denervation to improve heart failure with reduced ejection fraction: the IMPROVE-HF-I study

Netherlands Heart Journal - The aim of the present study was to assess the safety and efficacy of renal sympathetic denervation (RDN) in patients with heart failure with reduced ejection fraction...     

Quantification of LDL cholesteryl ester contribution to biliary steroids in the rat

The proportion of LDL cholesteryl ester converted to biliary steroids was quantified in the rat. The pre-existing pool of bile was allowed to drain for 10-12 h through a bile duct cannula. A single intravenous pulse injection of LDL labelled with [3H]cholesterol linoleyl ester was made, followed by a constant infusion of the same material in order to maintain constant specific radioactivity in plasma. A new steady state was achieved within 6 h and bile samples were then collected hourly until 12 h. Although substantial amounts (53-61 micrograms/h) of cholesteryl ester were released into the liver during LDL catabolism, only a very small fraction (0.8-1.90 micrograms/h) was found in biliary steroids. The proportion of LDL cholesteryl esters contributing to biliary steroids was only 1-2%. These results perhaps explain why perturbations to accelerate bile acid excretion have no effect on plasma LDL cholesterol concentration in the rat.     

Structure of the Saccharomyces cerevisiae cell wall: Mannoproteins released by zymolyase and their contribution to wall architecture

Purified zymolyase containing β-glucanase activity preferentially released a 29 kDa mannoprotein from isolated yeast cell walls and a high-molecular-mass (greater than 120 kDa) material. Endo-β-N-acetylglucosaminidase H digestion indicated that the 29 kDa mannoprotein contains a unique core coligosaccharide N-glycosidically linked to a 26 kDa peptide moiety. Cells grown in the presence of tunicamycin incorporated the nonglycosylated 26 kDa peptide into the wall, but not the large mannoprotein molecules. Treatment of isolated walls with SDS solubilized more than 30 different mannoproteins, one of tehm being the 29 kDa species, but the large-size molecules were not affected. Regenerating protoplasts incorporated into the forming walls most of the SDS-solubilizable species seen in mature cell walls, but the zymolyase-solubilizable mannoproteins were absent. Wall mannoproteins have also been compared with those of the periplasmic space, most of the species being commonly present at both compartments. Turnover of individual species has been studied by pulse and chase experiments. While mannoproteins from the walls remain stable for long periods, periplasmic molecules exhibit a rapid turnover rate.     

The relative contribution of somatomedin to the serum-stimulated growth of human fibroblasts

Culture conditions were defined allowing to demonstrate a stimulatory effect of both serum-contained and purified Somatomedin activity on incorporation of [3H]thymidine and replication of cultured normal human fibroblasts. The use of dialyzed human serum in MEM medium supplemented by 0.2 mM serine offered the necessary and sufficient culture conditions. A significant difference between normal and hypopituitary patients sera was found in their effect on the rate of [3H]thymidine incorporation (p < 0.0001) and on cell replication (p < 0.01). Purified Somatomedin-C, in MEM without serum, is a poor mitogen. Its activity was strongly enhanced by the addition of 0.1 % dialyzed serum and 0.2 mM serine without, however, exceeding the stimulatory level of 1 % whole normal serum. The requirement of concomitant presence, for optimal $\text{in}\text{vitro}$ cell growth, of different low and high MW serum components is discussed.