Neonatal echocardiography serves as a vital diagnostic tool for identifying structural and functional cardiac abnormalities in newborns. However, hands-on training remains severely limited due to the scarcity of accessible high-end ultrasound systems and the ethical constraints associated with practicing on vulnerable neonatal patients. These limitations underscore the need for scalable simulation-based training solutions. To address these challenges, this work presents a proof-of-concept simulator that incorporates a specialized visualization pipeline built on four-dimensional (4D) ultrasound data comprising of three-dimensional spatial information over time to simulate neonatal transthoracic echocardiography (TTE) procedures. The visualization pipeline enables efficient rendering and interaction with 4D data within the Unity game engine, thereby providing a scalable, cross-platform foundation for developing immersive Extended Reality (XR) ultrasound simulators suitable for low-end computing platforms.