Abstract
Heart failure (Heart failure, HF) is a complex clinical syndrome caused by any abnormality in the structure or function of the heart, resulting in impaired ventricular filling or ejection capacity, with mitochondrial dysfunction recognized as one of the key pathological foundations. In recent years, numerous studies have demonstrated that mitochondrial DNA (mtDNA) mutations play a significant role in cardiomyopathy and HF; however, systematic understanding of their modes of action in disease progression remains limited. Most studies have attributed the pathogenic effects of mtDNA mutations to impaired energy metabolism, emphasizing the consequences of defective oxidative phosphorylation and insufficient ATP production on myocardial function. Emerging evidence, however, indicates that mtDNA mutations also contribute to the development and progression of HF by inducing reactive oxygen species accumulation, disrupting mitochondrial structural and dynamic homeostasis, and activating innate immune inflammatory signaling pathways. Furthermore, variations in mtDNA mutation load and heteroplasmy levels constitute an important molecular basis for the diverse clinical phenotypes of HF, although the underlying mechanisms have yet to be systematically integrated. This review comprehensively summarizes the pathogenic mechanisms of cardiac mtDNA mutations and their heteroplasmy in HF, with particular emphasis on the intrinsic links among mitochondrial metabolic reprogramming, oxidative stress, immune activation, and myocardial remodeling, and outlines potential diagnostic and therapeutic strategies based on mitochondrial dysfunction and mtDNA stability.