Virtual heart models are multiscale computational tools for studying cardiac function from the cell to organ level. They are particularly useful for simulating the electrical activity of the heart, which is essential for triggering the muscle contractions necessary to pump life-sustaining blood throughout the body. Since studying 3D electrical activity within the heart of a patient is invasive, expensive, and time-consuming, virtual heart models can circumvent these limitations to more thoroughly investigate both normal and abnormal cardiac electrical function. This computational platform is also ideal for testing and developing cardiac electrotherapies in a safe, efficient, and cost-effective manner. This seminar will focus on the use of virtual heart models to develop safer and less painful electrotherapies for terminating ventricular fibrillation, a lethal electrical disturbance in the heart.