ABSTRACT
Myocardial fibrosis is a predominant pathological change of radiation-induced heart disease (RIHD) in late stage.It often occurs several or more than ten years after radiotherapy and can lead to myocardial remodeling, impaired cardiac function, and heart failure.At present there is no effective method to prevent or reverse the development of radiation-induced myocardial fibrosis.Many cells, cytokines, and other factors are involved in the development and progression of myocardial fibrosis in RIHD and some of them have been validated.But most investigators focused on the pathological changes and related mechanisms in early stage, and myocardial fibrosis was just regarded as an endpoint event.The definitive mechanisms of myocardial fibrosis in late stage remain unclear.This paper reveiws the studies about general mechanisms of myocardial fibrosis in RIHD and summarizes the roles of microcirculation dysfunction, mast cells, several cytokines, hypoxia, oxidative stress, and renin-angiotensin system, and points out the future research direction of the pathogenesis of myocardial fibrosis in RIHD.It provides new ideas for discovering the potential targets for clinical intervention of myocardial fibrosis in RIHD.