The overall goal of this project is to develop a 3D patient specific computational framework in FEniCS to simulate cryoballoon ablation. The model is validated, and the same framework is used to analyze the hemodynamics and temperature distribution in the left atrium during surgery. Different leakage positions of the cryoballoon are simulated to investigate the lesion formation and heat transfer rates across the cryoballoon. Analysis of a patient specific mitral regurgitation case is also considered.