Abstract 16340: Atrial Wall Thickness Features Predefine Human Right Atrial Driver: Insights Gained From Novel Structural Analysis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Jichao Zhao ◽  
Aleksei Mikhailov ◽  
Megan Subr ◽  
Aaqel Nalar ◽  
James Kennelly ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Resolution ◽  
Wall Thickness ◽  
Thickness Distribution ◽  
3D Structure ◽  
Structural Features ◽  
Right Atrial ◽  
Atrial Wall ◽  
Human Right ◽  
Crista Terminalis

Introduction: Atrial fibrillation (AF) is not effectively treated in clinics due to a lack of adequate tools for identifying AF drivers as targets in ablation treatment. Recent studies revealed that 30-50% of patients with persistent AF have drivers not only in the left atrium (LA) but also in the right atrium (RA). However, the precise substrate underlying RA AF drivers remains elusive. Hypothesis: High-resolution analysis of human atrial wall 3D structure can predict the occurrence of right atrial drivers. Methods: Coronary perfused explanted human atria (N=10, 46.2±14.7 y.o.;40% female) were optically mapped with high-resolution CMOS cameras. Sustained AF was induced by fast pacing and perfusion of adenosine and/or isoproterenol. Hearts were imaged at ~170μm 3 resolution by 9.4T gadolinium-enhanced MRI (Fig. A). A coupled PDE approach was utilized to estimate the atrial wall thickness (Fig. B). Fibrosis was identified above a signal intensity threshold validated by histology; and fibrosis density was constructed for each voxel by determining the percent of neighboring fibrotic voxels within a radius of 5 voxels. Results: Optical mapping identified 9 RA drivers in 6 hearts (H1-6) and 7 LA drivers in 5 hearts (H5, 6 and 8-10, Fig. C). All 9 RA AF drivers were anchored in myobundle structure in close proximity to the crista terminalis (CT). Wall thickness distribution in RA excluding the CT was similar to that in the LA (N=10, Fig. D). Structural analysis showed that RA with AF drivers (N=6) was thicker with greater wall variation and higher fibrosis density than RA without AF drivers (N=4, Fig. E). Furthermore, RA driver regions (N=9) were thicker and varied more than other RA regions (4.64±2.86 mm vs 4.56±2.57mm, p<0.05). Conclusions: For the first time, the 3D structural analysis demonstrates that structural features including atrial wall thickness and its variation near the CT can predict RA driver occurrences in human hearts and be used to improve targeted ablation.

scholarly journals Simultaneous endocardial and epicardial high-resolution mapping of the human right atrial wall

2016 ◽  
Vol 152 (3) ◽  
pp. 929-931 ◽  
Author(s):  
Paul Knops ◽  
Charles Kik ◽  
Ad J.J.C. Bogers ◽  
Natasja M.S. de Groot
Keyword(s):  
High Resolution ◽  
Right Atrial ◽  
Atrial Wall ◽  
Human Right ◽  
High Resolution Mapping ◽  
Resolution Mapping

scholarly journals 3D high-resolution atrial wall thickness maps using black-blood PSIR

2015 ◽  
Vol 17 (S1) ◽  
Author(s):  
Marta Varela ◽  
Christoph Kolbitsch ◽  
Adeline Theron ◽  
Ross Morgan ◽  
Markus Henningsson ◽  
...  
Keyword(s):  
High Resolution ◽  
Wall Thickness ◽  
Black Blood ◽  
Atrial Wall

scholarly journals Anatomical indicators of the heart and coronary arteries: An anthropometric study

2020 ◽  
Vol 7 (9) ◽  
pp. 3977-3984
Author(s):  
Marzieh Darvishi ◽  
Ardeshir Moayeri
Keyword(s):  
Coronary Artery ◽  
Coronary Arteries ◽  
Wall Thickness ◽  
Artery Bypass ◽  
Large Diameter ◽  
Left Ventricular ◽  
Right Atrial ◽  
Ventricular Wall ◽  
Atrial Wall ◽  
Ventricular Wall Thickness

Introduction: Previous studies confirm that there is no anthropometric index of normal Iranian hearts, including diameter of cardiac valve, thickness of myocardial septum and coronary artery variation. The purpose of this study was to assess the anatomical indexes of the human heart and coronary artery in the Iranian population. Methods: The study was performed with 207 adult human hearts in both sexes (182 male and 25 female), fixed in 10% formaldehyde. Myocardial thickness and diameter of heart valves were measured using a Vernier caliper. Assessments of the coronary artery were carried out after removal of the pericardium. Results: Analysis of 207 cadaver coronary arteries showed left coronary artery (LCA) dominance type was present in 6.3% of corpus, and balance was present in 4.3% of corpus, while the largest number (89.4%) had right coronary artery (RCA) dominance. The mean values of the morphometric data are as follows: right atrial wall thickness (2.08 +/- 0.04 mm), left atrial wall thickness (2.08 +/- 0.04 mm), interatrial wall thickness (4.92 +/- 0.08 mm), right ventricular wall thickness (3.35 +/- 0.05 mm), left ventricular wall thickness (8.36 +/- 0.13 mm), interventricular wall thickness (12.01 +/- 0.2 mm), diameter of the aorta (23.6 +/- 0.4 mm), diameter of the pulmonary artery (24.94 +/-  0.4 mm), large diameter of the mitral valve (34.16 +/- 0.27 mm), and large diameter of the tricuspid valve (38.8 +/- 0.24 mm). Conclusion: The anatomical knowledge of cardiac indicators and coronary artery data will be helpful and clinically relevant, especially for cardiac surgeons for coronary artery bypass grafting and coronary arteriography.

scholarly journals MicroCT as a Useful Tool for Analysing the 3D Structure of Lichens and Quantifying Internal Cephalodia in Lobaria pulmonaria

2021 ◽  
Vol 1 (2) ◽  
pp. 189-200
Author(s):  
Julia Gerasimova ◽  
Bernhard Ruthensteiner ◽  
Andreas Beck
Keyword(s):  
High Resolution ◽  
Computer Tomography ◽  
Structural Characteristics ◽  
3D Structure ◽  
Three Dimensional ◽  
Structural Features ◽  
Lobaria Pulmonaria ◽  
X Ray ◽  
Yield Information ◽  
Non Destructive

High-resolution X-ray computer tomography (microCT) is a well-established technique to analyse three-dimensional microstructures in 3D non-destructive imaging. The non-destructive three-dimensional analysis of lichens is interesting for many reasons. The examination of hidden structural characteristics can, e.g., provide information on internal structural features (form and distribution of fungal-supporting tissue/hypha), gas-filled spaces within the thallus (important for gas exchange and, thus, physiological processes), or yield information on the symbiont composition within the lichen, e.g., the localisation and amount of additional cyanobacteria in cephalodia. Here, we present the possibilities and current limitations for applying conventional laboratory-based high-resolution X-ray computer tomography to analyse lichens. MicroCT allows the virtual 3D reconstruction of a sample from 2D X-ray projections and is helpful for the non-destructive analysis of structural characters or the symbiont composition of lichens. By means of a quantitative 3D image analysis, the volume of internal cephalodia is determined for Lobaria pulmonaria and the external cephalodia of Peltigera leucophlebia. Nevertheless, the need for higher-resolution tomography for more detailed studies is emphasised. Particular challenges are the large sizes of datasets to be analysed and the high variability of the lichen microstructures.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

Closure of Secundum Atrial Septal Defect with Autologous Right Atrial Patch: Case Report

2005 ◽  
Vol 8 (2) ◽  
pp. 96 ◽  
Author(s):  
Osman Tansel Dar�in ◽  
Alper Sami Kunt ◽  
Mehmet Halit Andac
Keyword(s):  
Atrial Septal Defect ◽  
Right Atrium ◽  
Septal Defect ◽  
Complete Recovery ◽  
Interatrial Septum ◽  
Right Atrial ◽  
Atrial Wall ◽  
Residual Shunt ◽  
Asd Closure ◽  
The Right

Background: Although various synthetic materials and pericardium have been used for atrial septal defect (ASD) closure, investigators are continuing to search for an ideal material for this procedure. We report and evaluate a case in which autologous right atrial wall tissue was used for ASD closure. Case: In this case, we closed a secundum ASD of a 22-year-old woman who also had right atrial enlargement due to the defect. After establishing standard bicaval cannulation and total cardiopulmonary bypass, we opened the right atrium with an oblique incision in a superior position to a standard incision. After examining the secundum ASD, we created a flap on the inferior rim of the atrial wall. A stay suture was stitched between the tip of the flap and the superior rim of the defect, and suturing was continued in a clockwise direction thereafter. Considering the size and shape of the defect, we incised the inferior attachment of the flap, and suturing was completed. Remnants of the flap on the inferior rim were resected, and the right atrium was closed in a similar fashion. Results: During an echocardiographic examination, neither a residual shunt nor perigraft thrombosis was seen on the interatrial septum. The patient was discharged with complete recovery. Conclusion: Autologous right atrial patch is an ideal material for ASD closure, especially in patients having a large right atrium. A complete coaptation was achieved because of the muscular nature of the right atrial tissue and its thickness, which is a closer match to the atrial septum than other materials.

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