Cardiotoxicity is one of the major toxicity concerns when developing new drugs. However, these cardiotoxicity tests aren’t done until a drug has gone through years of development. LLNL scientists have developed a software suite called Cardioid that simulates the electrical current running through the heart tissue, triggering cells to contract like cascading dominoes and causing the heart to beat. These simulations, which generate copious amounts of virtual data, can be used to train a patented machine learning system. Once trained, actual clinical results could be used as a ground truth to develop a more accurate ML system that can determine how the heart is functioning. Cardioid along with the patented ML system have the potential to make drugs safer, save time, money and lives.