Postoperative radiotherapy increase the overall survival rate offor breast cancer improves overall survivalpatients, but. Nevertheless, the heart is at risk of radioactive heart damageradiation-induced cardiac injury due to its anatomical location, which is inevitably exposed to radiation during radiotherapy. The heart is considered a "high-risk organ" sensitive to radiation, and its radiation dose should be as low as possible. Previous studies have evaluated the effect of overall heart radiation dose on long-term cardiovascular events, but the. However, new study has found that the average heart dose does not accurately reflect the degree of heart radiation exposure. In recent years, more and morewidespread attention has been paid to subclinical cardiac injury after radiotherapy, aiming at early identification of latent cardiac injury. In addition, the relationship between specific cardiac substructural doses and arrhythmias is unclear. This paper focuses onIn this article, the limitations of average cardiac dose in predicting radioactive heart injuryradiation- induced cardiac injury, the indicators of early identification of the indicators for cardiac injury and the influencing factors of radiation-induced cardiac injury in breast cancer radioactive heart injurywere illustrated, and focuses on the relationship between radiation damage of different cardiac substructures and arrhythmia was evaluated, so asaiming to achieve fine cardiac risk management in breast cancer patients and reduce the non-cancer mortality in breast cancer patients.