A computer-aided instruction program for teaching cardiac rhythms and arrhythmias to second year medical students at Case Western Reserve University was created. The program seeks to integrate multiple levels of information in a visually exciting way by combining various simultaneous animations of the heart, its electrical system, and the standard representations of the electrical system (the ladder diagram and the EKG). The program features a text that covers the most important information about 22 cardiac arrhythmias in a step-by-step approach, illustrating all didactic points with high-resolution graphics. Students are instructed in the genesis and propagation of arrhythmia, as well as in the recognition of characteristic EKG features. The program is menu-driven, offering a teaching series, a quiz, and random access to each individual arrhythmia. The text describes the development of the program, its architecture, animation techniques, use, and evaluation by cardiologists and medical students. Copies of sample graphics screens are provided.