NHỮNG YẾU TỐ ẢNH HƯỞNG ĐẾN KÍCH THƯỚC NHĨ TRÁI TRÊN SIÊU ÂM TIM 3D Ở BỆNH NHÂN RUNG NHĨ KHÔNG DO BỆNH VAN TIM

Giãn nhĩ trái là một yếu tố nguy cơ của đột quỵ và là yếu tố quyết định cho sự thành công của chiến lược kiểm soát nhịp tim ở bệnh nhân rung nhĩ. Tuy nhiên, những yếu tố liên quan đến thể tích nhĩ trái ở bệnh nhân rung nhĩ vẫn chưa được hiểu đầy đủ. Mục tiêu: Tìm hiểu những yếu tố liên quan đến giãn nhĩ trái trên siêu âm tim 3D ở bệnh nhân rung nhĩ không do bệnh van tim. Đối tượng và phương pháp: Nghiên cứu mô tả cắt ngang tiến hành trên các bệnh nhân rung nhĩ không do bệnh van tim. Tất cả các bệnh nhân được hỏi bệnh, thăm khám lâm sàng kỹ lưỡng và làm bệnh án theo mẫu, làm một số thăm dò và xét nghiệm sinh hoá, làm ĐTĐ 12 chuyển đạo, làm siêu âm tim 2D và 3D theo hướng dẫn của Hội Siêu âm Tim Hoa Kỳ. Thể tích nhĩ trái được đánh giá trên siêu âm tim 3D bằng phần mềm Heart Model. Kết quả: Từ 07/2020 đến 07/2021 có 80 bệnh nhân được đưa vào nghiên cứu, tuổi trung bình60,7 ± 4,8, nam 48.8%, nữ 51.2%. Thể tích nhĩ trái trên siêu âm tim 3D có mối liên quan với các yếu tố như tiền sử tăng huyết áp (β= 1,3 ± 0,9ml/m2), đái tháo đường (β=0,8 ± 0,2ml/m2), bệnh thận mạn (β=2,4 ± 0,9 ml/m2), bệnh mạch vành (β=2,2 ± 0,5) và rối loạn chức năng tâm trương (β=2,3 ± 4,6 ml/m2). Khi phân tích đa biến, bệnh mạch vành (β=2,5 ± 0,4 ml/m2), bệnh thận mạn (β=2,9 ± 0,3 ml/m2) và rối loạn chức năng tâm trương thất trái (β=2,4 ± 0,4ml/m2) cho thấy mối liên quan độc lập với thể tích nhĩ trái ở bệnh nhân rung nhĩ không do bệnh van tim. Kết luận: Rối loạn chức năng tâm trương thất trái, bệnh thận mạn, bệnh mạch vành là những yếu tố có ảnh hưởng đến giãn thể tích nhĩ trái trên siêu âm tim 3D ở các bệnh nhân rung nhĩ không do bệnh van tim.

Sequential Coupling Shows Minor Effects of Fluid Dynamics on Myocardial Deformation in a Realistic Whole-Heart Model

Background: The human heart is a masterpiece of the highest complexity coordinating multi-physics aspects on a multi-scale range. Thus, modeling the cardiac function in silico to reproduce physiological characteristics and diseases remains challenging. Especially the complex simulation of the blood's hemodynamics and its interaction with the myocardial tissue requires a high accuracy of the underlying computational models and solvers. These demanding aspects make whole-heart fully-coupled simulations computationally highly expensive and call for simpler but still accurate models. While the mechanical deformation during the heart cycle drives the blood flow, less is known about the feedback of the blood flow onto the myocardial tissue.Methods and Results: To solve the fluid-structure interaction problem, we suggest a cycle-to-cycle coupling of the structural deformation and the fluid dynamics. In a first step, the displacement of the endocardial wall in the mechanical simulation serves as a unidirectional boundary condition for the fluid simulation. After a complete heart cycle of fluid simulation, a spatially resolved pressure factor (PF) is extracted and returned to the next iteration of the solid mechanical simulation, closing the loop of the iterative coupling procedure. All simulations were performed on an individualized whole heart geometry. The effect of the sequential coupling was assessed by global measures such as the change in deformation and—as an example of diagnostically relevant information—the particle residence time. The mechanical displacement was up to 2 mm after the first iteration. In the second iteration, the deviation was in the sub-millimeter range, implying that already one iteration of the proposed cycle-to-cycle coupling is sufficient to converge to a coupled limit cycle.Conclusion: Cycle-to-cycle coupling between cardiac mechanics and fluid dynamics can be a promising approach to account for fluid-structure interaction with low computational effort. In an individualized healthy whole-heart model, one iteration sufficed to obtain converged and physiologically plausible results.

Best Practice Through Broken Triangle, Square and Heart Can Grow Constitutional Awareness and Increase Citizenship Values

This Best Practice is the best experience in learning to increase awareness about constituting and improving learning outcomes through the Broken Square Triangle, Square, and Heart model in Class VIII E of SMP Negeri 2 Wonosari Gunungkidul in the Even Semester of the 2019/2020 Academic Year. The results of the teacher's observations during PBM, students like to littering, wearing colorful shoes, long hair, unidentified uniform at SMPN 2 Wonosari, less respect for teachers in class, not concentrating on teaching and learning activities, sleeping in class. After studying with the Broken Triangle, Square and Heart models, there is a change in constitutional awareness, as evidenced by the research data. At the first meeting with the lecture method, the violation was 18.89%. When KBM uses the Broken Triangle, Square and Heart model, in the second meeting there is a violation of 2.59% and the third meeting there is a violation of 1.48%. This has proven to be an increase in constitutional awareness. From the learning outcomes, the lecture method shows an average result of 59.47, with the Broken Triangle, Square and Heart model, an average of 66.0 and 86.13. Thus, it shows that the Broken Triangle, Square and Heart models are more effectively used in PPKn learning.

Operative Workflow from CT to 3D Printing of the Heart: Opportunities and Challenges

Medical images do not provide a natural visualization of 3D anatomical structures, while 3D digital models are able to solve this problem. Interesting applications based on these models can be found in the cardiovascular field. The generation of a good-quality anatomical model of the heart is one of the most complex tasks in this context. Its 3D representation has the potential to provide detailed spatial information concerning the heart’s structure, also offering the opportunity for further investigations if combined with additive manufacturing. When investigated, the adaption of printed models turned out to be beneficial in complex surgical procedure planning, for training, education and medical communication. In this paper, we will illustrate the difficulties that may be encountered in the workflow from a stack of Computed Tomography (CT) to the hand-held printed heart model. An important goal will consist in the realization of a heart model that can take into account real wall thickness variability. Stereolithography printing technology will be exploited with a commercial rigid resin. A flexible material will be tested too, but results will not be so satisfactory. As a preliminary validation of this kind of approach, print accuracy will be evaluated by directly comparing 3D scanner acquisitions to the original Standard Tessellation Language (STL) files.