Atrial fibrillation (AFib) is the most common cardiac arrhythmia and is associated with an increased risk of stroke, highlighting the need for accessible and engaging educational resources. This project, ‘AFib in AR’, is an interactive AR mobile application using an animated 3D anatomical heart to support understanding of AFib and its associated risks. An anatomically based heart model was developed from open-source medical imaging data and incorporated into an Android application with AR, educational information, animation, labels, and accessibility-focused design. The application was evaluated through usability, motivation and engagement, cognitive load, and perceived validity. Results were generally positive, with participants finding the application clear, easy to learn, and engaging, while anatomist expert feedback supported its perceived accuracy and educational appropriateness. However, the small and varied participant sample, adapted surveys, and limited number of expert reviewers mean the findings should be interpreted cautiously. Overall, ‘AFib in AR’ demonstrates the potential of combining animated cardiac anatomy and AR to support AFib education.