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The left atrial appendage is a blind ending cardiac structure prone to blood stasis due to its morphology. This structure is a preferred region of thrombogenesis in relation to reduced myocardial contractility of the atrial wall. Blood stasis occurs primarily in low flow conditions. One of the tasks of echocardiography is the analysis of morphology and function of the left atrial appendage. The detection of thrombi by echocardiography is difficult and must be carried out thoroughly and carefully to avoid potential complications—especially in the context of rhythm control. The assessment of thromboembolic risk, especially in patients with unknown and presumed atrial fibrillation is a second challenge by characterizing atrial function and flow conditions in the left atrial appendage. Thus, this proposal focuses on the obvious problems of echocardiography when assessing left atrial appendage and the role of this method in planning a potential interventional closure of left atrial appendage.

The success of hematopoietic stem cell transplantation (HSCT) lies with the ability of the engrafting immune system to remove residual leukemia cells a graft-versus-leukemia effect (GvL), caused either spontaneously post-HSCT or donor lymphocyte infusion. GvL effects can also be initiated by allogenic mismatched natural killer cells, antigen-specific T cells, and activated dendritic cells of leukemic origin. The history and further application of this GvL effect and the main mechanisms will be discussed and reviewed in this chapter.

During Atrial Fibrillation (AF) more than 90% of the left atrial thrombi responsible for thromboembolic events originate in the left atrial appendage (LAA), a complex small sac protruding from the left atrium (LA). Current available treatments to prevent thromboembolic events are oral anticoagulation, surgical LAA exclusion, or percutaneous LAA occlusion. However, the mechanism behind thrombus formation in the LAA is poorly understood. The aim of this work is to analyse the hemodynamic behaviour in four typical LAA morphologies - \"Chicken wing\", \"Cactus\", \"Windsock\" and \"Cauliflower\" - to identify potential relationships between the different shapes and the risk of thrombotic events. Computerised tomography (CT) images from four patients with no LA pathology were segmented to derive the 3D anatomical shape of LAA and LA. Computational Fluid Dynamic (CFD) analyses based on the patient-specific anatomies were carried out imposing both healthy and AF flow conditions. Velocity and shear strain rate (SSR) were analysed for all cases. Residence time in the different LAA regions was estimated with a virtual contrast agent washing out. CFD results indicate that both velocity and SSR decrease along the LAA, from the ostium to the tip, at each instant in the cardiac cycle, thus making the LAA tip more prone to fluid stagnation, and therefore to thrombus formation. Velocity and SSR also decrease from normal to AF conditions. After four cardiac cycles, the lowest washout of contrast agent was observed for the Cauliflower morphology (3.27% of residual contrast in AF), and the highest for the Windsock (0.56% of residual contrast in AF). This suggests that the former is expected to be associated with a higher risk of thrombosis, in agreement with clinical reports in the literature. The presented computational models highlight the major role played by the LAA morphology on the hemodynamics, both in normal and AF conditions, revealing the potential support that numerical analyses can provide in the stratification of patients under risk of thrombus formation, towards personalised patient care.

Background: This study aims to investigate the left atrial appendage (LAA) regarding external morphology, positional relation of the ostium of LAA to the left superior pulmonary vein (LSPV), ostium shape, ostium diameter and functional depth. Materials and methods: Left atrial appendages of 65 cadaveric hearts were examined. Results: The prevalence of Cauliflower, Windsock, Cactus and Chicken wing type of LAA were 27.7%, 27.7%, 26.1%, and 18.5%, respectively. LAA with two lobes was the most common. All specimens showed no accessory LAA. The relation of the ostium to the LSPV was found in two types which were mid-type (LAA ostium was at the same level as LSPV) in 29 (44.6%) cases and inferior type (LAA ostium was below the level of LSPV) in 36 (55.4%) cases. The shapes of LAA ostium were oval and round with a prevalence of 55.4% and 44.6%, respectively. The diameter of round type ranged from 9.53 to 21.51 mm with a mean of 14.56 ± 2.6 mm. While in oval type, the long and short diameters ranged from 11.61 to 31.71 mm with a mean of 14.23 ± 4.2 mm and from 6.70 to 23.90 mm with a mean of 11.66 ± 3.5 mm, respectively. The Surface area of the ostium was calculated from the ostium diameter, range from 71.29 to 594.92 mm2 with a mean of 169.56 ± 84.73 mm2. There was no statistically significant difference of the surface area between LAA types. The mean functional depth of LAA was 11.57 ± 4.43 mm. The functional depth of the Windsock-type appeared to be statistically significant from the others. However, there was no correlation between the functional depth and the ostium surface area. Conclusions: This morphometric data might be beneficial for deployment of LAA closure device in the Thai population.

Reflecting both the worldwide importance of AF, as well as the worldwide performance of AF ablation, this document is the result of a joint partnership between the HRS, EHRA, ECAS, the Asia Pacific Heart Rhythm Society (APHRS), and the Latin American Society of Cardiac Stimulation and Electrophysiology (Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología [SOLAECE]). The purpose of this 2017 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a writing group, convened by these five international societies. The writing group is composed of 60 experts representing 11 organizations: HRS, EHRA, ECAS, APHRS, SOLAECE, STS, ACC, American Heart Association (AHA), Canadian Heart Rhythm Society (CHRS), Japanese Heart Rhythm Society (JHRS), and Brazilian Society of Cardiac Arrhythmias (Sociedade Brasileira de Arritmias Cardíacas [SOBRAC]). Rather, the ultimate judgment regarding care of a particular patient must be made by the health care provider and the patient in light of all the circumstances presented by that patient.

Background: This paper aimed to appraise the diagnostic precision of assorted methodologies to identify left atrial/left atrial appendage (LA/LAA) thrombus through a network meta-assessment. Methods: Methodologically, we conducted a comprehensive literature search across multiple databases. Utilizing the risk of bias tool from the Cochrane Collaboration, methodological quality of included studies was critically assessed and potential publication bias was examined via funnel plots. The subsequent data analysis was executed using Stata software, with the most efficacious diagnostic modalities being determined based on cumulative ranking curve (SUCRA) values. Results: We scrutinized a sum of 18 papers, comprising 4102 subjects and utilizing 10 different diagnostic techniques. The hierarchical results derived from the network meta-analysis indicated that in regards to sensitivity, the dual-source cardiac computed tomography (DSCT) was superior (with a SUCRA value of 71.7%), it was succeeded by 3-minute delayed cardiac computed tomography (CCT) (scoring 66.8%), which surpassed the transesophageal echocardiography (TEE) (holding a SUCRA value of 57.5%). In terms of specificity, DSCT was the best (SUCRA value of 84.3%), followed by three dimensional (3D) cardiac magnetic resonance imaging (3D-CMRI) (SUCRA value of 78.0%), which was better than TEE (SUCRA value of 66.6%). In terms of positive likelihood ratio (PLR), 6-minute delayed CCT (SUCRA value of 85.6%) was superior to 3-minute delayed CCT (SUCRA value of 80.1%), both of which were superior to TEE (SUCRA value of 69.1%). DSCT (SUCRA value of 89.3%) had the best negative likelihood ratio (NLR), while DSCT (SUCRA value of 79.9%) had the highest accuracy. Conclusions: This study demonstrated that DSCT outperformed TEE in sensitivity, specificity, NLR, and accuracy in identifying thrombus of LA/LAA among patients suffering from atrial fibrillation. Our conclusion is that DSCT is the best in diagnosing LA/LAA. In addition, 3D-CMRI and 3-minute delayed CCT are expected to replace TEE.

This article presents an ultra-compact (1.02λ × 1.02λ mm 2 ) and highly isolated 8-port MIMO antenna designed for NR-n46 and n79 bands, as well as licensed assisted access (LAA). A systematic study was performed to choose an optimal antenna (Design-3) among all designs (Design-1, Design-2, and Design-3) after systematic study (parametric study and circuit theory analysis) of Ref. design-1, Ref. design-2, Ref. design-3 and Ref. design-4. An optimal and proposed antenna geometry consists of two orthogonal radiators on the top and a novel ground plane (rectangular ring, centered annular ring and plus shaped slot) at the bottom of each corner of the dielectric substrate to create a perfectly matched 8-port antenna. The proposed antenna demonstrates a wideband frequency operation of 700 MHz within the 4.75–5.45 GHz range, specifically in the sub-6 GHz 5G band. It resonates at 5.2 GHz, achieving an isolation of 33 dB, a gain of 4.7 dB, and a radiation efficiency of 92.5%. The MIMO characteristics, including ECC, DG, TARC, MEG, and CCL, were evaluated and found to be within acceptable parameters. The antenna was fabricated, tested in a laboratory setting, and its performance was validated against simulated results.

Background Atrial fibrillation is the most important risk factor for left atrial appendage (LAA) thrombi, a potentially life‐threatening condition. Thrombus resolution may prevent embolic events and allow rhythm‐control strategies, which have been shown to reduce cardiovascular complications. Hypothesis There is no significant difference between phenprocoumon and non‐Vitamin K‐dependent oral anticoagulants (NOACs) in the resolution of LAA‐thrombi in a real‐world setting. Methods Consecutive patients with LAA‐thrombi from June 2013 to June 2017 were included in an observational single‐center analysis. The primary endpoint was defined as the resolution of the thrombus. The observational period was 1 year. Resolutions rates in patients on phenprocoumon or NOACs were compared and the time to resolution was analyzed. Results We identified 114 patients with LAA‐thrombi. There was no significant difference in the efficacy of resolution between phenprocoumon and NOACs (p = .499) at the time of first control which took place after a mean of 58 ± 42.2 (median 48) days. At first control most thrombi were dissolved (74.6%). The analysis after set‐time intervals revealed a resolution rate of 2/3 of LAA‐thrombi after 8–10 weeks in the phenprocoumon and NOAC groups. After 12 weeks a higher number of thrombi had resolved in the presence of NOAC (89.3%) whereas in the presence of phenprocoumon 68.3% had resolved (p = .046). Conclusion In this large observational study NOACs were found to be potent drugs for the resolution of LAA‐thrombi. In addition, the resolution of LAA‐thrombi was found to be faster in the presence of NOAC as compared to phenprocoumon.

Aim To investigate the role of cardiac CT angiography (CCTA) in predicting optimal left atrial appendage (LAA) occluder size and procedure outcome. Methods and results Thirty-six patients underwent pre-procedural CCTA. CCTA and TEE LAA orifice diameters and perimeters were compared with the implanted device size. CCTA 3D configuration was correlated with procedure outcome. Watchman™ device (N = 18): diameters were 21 ± 4, 26 ± 5 and 25 ± 3 mm for TEE, CCTA and inserted device, respectively. Average perimeters were 61 ± 10, 74 ± 8 and 78 ± 11 mm for TEE, CCTA and inserted device, respectively. Better agreement with the device size was found for CCTA compared to TEE (Bland–Altman). ACP™ device (N = 15): diameters were 20 ± 5, 25 ± 4 and 23 ± 4 for TEE, CCTA and inserted device, respectively. Average perimeters were 58 ± 11, 72 ± 15 and 72 ± 13 mm for TEE, CCTA and inserted device, respectively. Excellent correlation and agreement with the device size was found for CCTA compared to TEE. CCTA perimeter >100 mm and “cactus” 3D configuration had a specificity of 96 and 81% respectively for procedure failure. Conclusions CCTA LAA ostial perimeter predicted better the optimal occluder size as compared with the currently used LAA TEE diameter. Moreover, CCTA 3D data may help in predicting potential complications.

In this paper, two sector beam scanning approaches (BSAs) based on element position perturbations (EPPs) in the azimuth plane are introduced. In EPP-BSA, the elements’ excitations are kept constant and the elements’ positions in the direction normal to the array line are changed according to a predetermined EPP pattern. The magnitude and repetition rate of the selected EPP pattern determines the steering angle of the main beam. However, EPP-BSA results in a wide scanning range with a significant increase in the side lobe level (SLL). To mitigate this drawback, a reduction in the SLL of the array pattern is firstly performed using the single convolution/genetic algorithm (SC/GA) technique and then perturbing the elements’ positions in the azimuth plane. This combination between SLL reduction and EPP-BSA (SLL/EPP-BSA) results in a smaller scanning range with a relatively constant half power beamwidth (HPBW) and a much lower SLL. In addition, keeping the synthesized excitation coefficients constant without adding progressive phase shifters facilitates the manufacturing process and reduces the cost of the feeding network. Furthermore, a planar antenna array thinning approach is proposed to realize the EPP-BSA. The results are realized using the computer simulation technology (CST) microwave studio software package, which provides users with an optimized modeling environment and results in realizable and realistic designs.