Simulating the cardiac function requires the numerical solution of multi-physics and multi-scale mathematical models. This underscores the need for streamlined, accurate, and high-performance computational tools. Despite the dedicated endeavors of various research teams, comprehensive and user-friendly software programs for cardiac simulations are still in the process of achieving full maturity within the scientific community. This work introduces lifex-ep, a publicly available software for numerical simulations of the electrophysiology activity of the cardiac muscle, under both physiological and pathological conditions. lifex-ep employs the monodomain equation to model the heart's electrical activity. It incorporates both phenomenological and second-generation ionic models. These models are discretized using the Finite Element method on tetrahedral or hexahedral meshes. Additionally, lifex-ep integrates the generation of myocardial fibers based on Laplace-Dirichlet Rule-Based Methods, previously released in Africa et al., 2023, within lifex-fiber. This paper provides a concise overview of the mathematical models and numerical methods underlying lifex-ep, along with comprehensive implementation details and instructions for users. lifex-ep features exceptional parallel speedup, scaling efficiently when using up to thousands of cores, and its implementation has been verified against an established benchmark problem for computational electrophysiology. We showcase the key features of lifex-ep through various idealized and realistic simulations. lifex-ep offers a user-friendly and flexible interface. lifex-ep provides easy access to cardiac electrophysiology simulations for a wide user community. It offers a computational tool that integrates models and accurate methods for simulating cardiac electrophysiology within a high-performance framework, while maintaining a user-friendly interface.

翻译：心脏功能的模拟需要多物理场、多尺度数学模型的数值求解。这凸显了对精简、精确且高性能计算工具的需求。尽管各研究团队付出了不懈努力，但在科学界，全面且用户友好的心脏模拟软件仍在逐步成熟的过程中。本文介绍了 lifex-ep，一款用于心脏肌肉电生理活动数值模拟的公开可用软件，可模拟生理与病理条件下的情况。lifex-ep 采用单域方程来建模心脏的电活动，并整合了现象学与第二代离子模型。这些模型通过有限元方法在四面体或六面体网格上进行离散。此外，lifex-ep 集成了基于拉普拉斯-狄利克雷规则方法的肌纤维生成功能，该功能此前已在 Africa 等人（2023 年）的 lifex-fiber 中发布。本文简要概述了 lifex-ep 背后的数学模型和数值方法，并提供了全面的实现细节和使用说明。lifex-ep 具有出色的并行加速能力，可在多达数千个核心上高效扩展，其实现已通过与计算电生理学领域的标准基准问题进行验证。我们通过各种理想化与真实模拟展示了 lifex-ep 的关键特性。lifex-ep 提供用户友好且灵活的接口，为广泛的用户社区提供了便捷访问心脏电生理模拟的途径。它为用户提供了一个整合模型与精确方法、在高性能框架内模拟心脏电生理学，同时保持用户友好界面的计算工具。