Deficient myocardial organization and pathological fibrosis in fetal aortic stenosis-association of prenatal ultrasound with postmortem histology

In fetal aortic stenosis (AS), it remains challenging to predict left ventricular development over the course of pregnancy. Myocardial organization, differentiation and fibrosis could be potential biomarkers relevant for biventricular outcome. We present four cases of fetal AS with varying degrees of severity and associate myocardial deformation on fetal ultrasound with postmortem histopathological characteristics. During routine fetal echocardiography, speckle tracking recordings of the cardiac four-chamber view were performed to assess myocardial strain as parameter for myocardial deformation. After pregnancy termination, postmortem cardiac specimens were examined using immunohistochemical labeling (IHC) of key markers for myocardial organization, differentiation and fibrosis and compared to normal fetal hearts. Two cases with critical AS presented extremely decreased left ventricular (LV) strain on fetal ultrasound. IHC showed overt endocardial fibro-elastosis, which correlated with pathological fibrosis patterns in the myocardium and extremely disturbed cardiomyocyte organization. The LV in severe AS showed mildly reduced myocardial strain and less severe disorganization of the cardiomyocytes. In conclusion, the degree of reduction in myocardial deformation corresponded with high extent to the amount of pathological fibrosis patterns and cardiomyocyte disorganization. Myocardial deformation on fetal ultrasound seems to hold promise as a potential biomarker for left ventricular structural damage in AS.Developmen

Validation and feasibility of echocardiographic assessment of systemic right ventricular function: serial correlation with MRI

Background: Inherent to its geometry, echocardiographic imaging of the systemic right ventricle (RV) is challenging. Therefore, echocardiographic assessment of systemic RV function may not always be feasible and/or reproducible in daily practice. Here, we aim to validate the usefulness of a comprehensive range of 32 echocardiographic measurements of systemic RV function in a longitudinal cohort by serial assessment of their correlations with cardiac magnetic resonance (CMR)-derived systemic RV ejection fraction (RVEF).Methods: A single-center, retrospective cohort study was performed. Adult patients with a systemic RV who underwent a combination of both CMR and echocardiography at two different points in time were included. Off-line analysis of echocardiographic images was blinded to off-line CMR analysis and vice versa. In half of the echocardiograms, measurements were repeated by a second observer blinded to the results of the first. Correlations between echocardiographic and CMR measures were assessed with Pearson's correlation coefficient and interobserver agreement was quantified with intraclass correlation coefficients (ICC).Results: Fourteen patients were included, of which 4 had congenitally corrected transposition of the great arteries (ccTGA) and 10 patients had TGA late after an atrial switch operation. Eight patients (57%) were female. There was a mean of 8 years between the first and second imaging assessment. Only global systemic RV function, fractional area change (FAC), and global longitudinal strain (GLS) were consistently, i.e., at both time points, correlated with CMR-RVEF (global RV function: r = -0.77/r = -0.63; FAC: r = 0.79/r = 0.67; GLS: r = -0.73/r = -0.70, all p-values < 0.05). The ICC of GLS (0.82 at t = 1, p = 0.006, 0.77 at t = 2, p = 0.024) was higher than the ICC of FAC (0.35 at t = 1, p = 0.196, 0.70 at t = 2, p = 0.051) at both time points.Conclusion: GLS appears to be the most robust echocardiographic measurement of systemic RV function with good correlation with CMR-RVEF and reproducibility.Cardiolog

The Leiden Convention coronary coding system: translation from the surgical to the universal view

Aims: The Leiden Convention coronary coding system structures the large variety of coronary anatomical patterns; isolated and in congenital heart disease. It is widely used by surgeons but not by cardiologists as the system uses a surgeons' cranial view. Since thoracic surgeons and cardiologists work closely together, a coronary coding system practical for both disciplines is mandatory. To this purpose, the 'surgical' coronary coding system was adapted to an 'imaging' system, extending its applicability to different cardiac imaging techniques.Methods and results: The physician takes place in the non-facing sinus of the aortic valve, oriented with the back towards the pulmonary valve, looking outward from the sinus. From this position, the right-hand sinus is sinus 1, and the left-hand sinus is sinus 2. Next, a clockwise rotation is adopted starting at sinus 1 and the encountered coronary branches described. Annotation of the normal anatomical pattern is 1R-2LCx, corresponding to the 'surgical' coding system. The 'imaging' coding system was made applicable for Computed Tomography (CT), Magnetic Resonance Imaging (MRI), echocardiography, and coronary angiography, thus facilitating interdisciplinary use. To assess applicability in daily clinical practice, images from different imaging modalities were annotated by cardiologists and cardiology residents and results scored. The average score upon evaluation was 87.5%, with the highest scores for CT and MRI images (average 90%).Cardiolog

The effect of rainfall intensity on surface runoff and sediment yield in the grey dunes along the Dutch coast under conditions of limited rainfall acceptance.

Surface runoff and sediment yield in the grey dunes along the Dutch coast are rare events restricted to conditions of water repellency in summer. The sediment moves in mudflow-like tongues. From March 1989 to December 1990, weekly surface runoff and sediment yield have been measured on an experimental plot, along with a number of meteorological parameters. Rainfall intensity is more important than total amount of precipitation for the production of runoff and sediment. Rainfall intensity affects the erosion process in two ways: by supplying the large amount of water needed for the high water: sand ratio in the sand flow, and by providing the high frequency drop impact needed to maintain a high hydraulic pressure in the sand flow

Water and solute fluxes in dry coastal dune grasslands: the effects of grazing and increased nitrogen deposition

A five-year monitoring study has been carried out to examine the combined effects of grazing and atmospheric nitrogen deposition on water and solute fluxes in dry coastal dune grasslands. Two vegetation types were studied: (a) a short, species-rich stand on calcareous sand (foredune site) and (b) a short, species-poor stand on partly decalcified soil on calcareous sand (innerdune site). In each stand four experimental plots were created: (1) control, (2) fertilized with nitrogen, (3) excluded from grazing by rabbits and (4) combination of fertilization and exclusion of grazing by rabbits. Due to the large spatial variability of the soil water content, no differences between the treatments could be measured. Average soil water content at 10 cm depth is very small (3-5%) from May until October and does not increase after rainfall. However, measured soil water content at 20 cm and 50 cm depth increased after rainfall. In winter, nearly all measured soil water contents increase upon rainfall, although sometimes one soil water content remained dry till the end of the next summer. In summer it was impossible to sample soil water for the estimation of the solute concentrations due to the very small soil water content. Therefore, only solute concentrations of the winter period could be evaluated. Without fertilization, fluxes of nitrogen out of the soil system are below the incoming flux, due to storage in the biomass and in the soil compartment. When fertilized, 70% of the added NH4 +-N was leached from the foredune soil profile as NO3 --N, due to nitrification. Conversely, at the grazed innerdune site most of the added nitrogen remained in the system. Here, nitrification rates will be small due to the decalcified topsoil and NH4 +-N is not easily leached out of the soil compartment. At the exclosures of the innerdune site, about 15% of the amount of the added fertilizer N was leached, after added NH4 + is taken up by the plants and partly washed out as nitrate after mineralization and nitrification of dead biomass