## 1 Introduction  
The anatomy and physiology of the heart continue to be challenging subjects for medical students in their daily learning. For example, many students struggle to develop a solid understanding of ECG interpretation during their studies [1]. One key reason is that traditional two-dimensional teaching methods, like textbooks, often fall short when it comes to conveying three-dimensional processes, like cardiac excitation propagation, as they are frequently perceived as overly abstract and complex [2]. Studies have shown that the vast amount of anatomical knowledge that students must acquire during their medical studies, combined with the limited opportunities to apply this knowledge in practice, poses a significant challenge to the anatomical learning process [3]. Moreover, difficult anatomical conditions pose a challenge not only for students as future doctors in their daily learning routines but also for many patients with congenital heart defects who have only a limited understanding of their own condition. A deeper understanding can significantly contribute to better health outcomes [4]. Extended reality (XR) encompasses immersive technologies like virtual reality (VR) and augmented reality (AR), which are transforming modern learning methods. VR allows users to fully immerse themselves in a computer-generated 3D environment, completely replacing the real world, while AR enhances the physical environment by overlaying digital information and interactive elements. These technologies hold the potential to create engaging, hands-on learning experiences that improve comprehension, especially for complex subjects, and increase student motivation [5, 6]. _Background and Literature Review: Current Applications of AR in Medical and Cardiovascular Education_  
For physicians, AR enables more targeted and individualized therapy planning and execution. For example, data from cross-sectional imaging (CT or MRI) can be used to create complete three-dimensional representations of the heart, which already allow for full simulation of procedures like transcatheter aortic valve replacement (TAVR) [7]. In procedural planning and preparation, it offers added value through a more precise understanding of the three-dimensional spatial relationships of anatomical structures [8]. In congenital heart surgery, the use of 3D models can positively impact preoperative planning for complex heart defects [9] and is already being used in the form of AR and VR for preoperative education and anxiety reduction in patients [10, 11]. Likewise, [PERSON] et al. demonstrated that VR-based preoperative planning can reduce anxiety in patients undergoing congenital heart surgery [12]. The recent literature describes that a three-dimensional model can improve the safety and planning of congenital cardiac surgical treatments and is furthermore suitable for the training of medical professionals and the education of parents [13]. Beyond procedural planning, AR provides interactive and enhanced learning experiences in medical education [14]. For example, [PERSON] et al. demonstrated in a randomized control trial that the use of a 3D virtual anatomical model significantly improved students' understanding and retention of anatomical structures compared to traditional 2D resources [15]. Studies have shown that learning anatomy in groups can enhance learning performance [16]. A meta-analysis by [PERSON] and [PERSON] highlighted that three-dimensional visualization technologies are particularly effective in anatomy learning settings [17]. Moreover, VR facilitates the exploration of complex anatomy without the need for expansive cadavers [18]. The use of virtual reality (VR), where users are completely immersed in a virtual environment, can further improve the quality of medical education, especially for interventions and surgeries, thereby reducing potential peri-procedural complications [19].