Mitochondrial dysfunction is increasingly recognized as a critical driver in the pathogenesis of cardiovascular diseases. Mitochondrial quality control (MQC) is an ensemble of adaptive mechanisms aimed at maintaining mitochondrial integrity and functionality and is essential for cardiomyocyte viability and optimal cardiac performance under the stress of cardiovascular pathology. The key MQC components include mitochondrial fission, fusion, mitophagy, and mitochondria-dependent cell death, each contributing uniquely to cellular homeostasis. The dynamic interplay among these processes is intricately linked to pathological phenomena, such as redox imbalance, calcium overload, dysregulated energy metabolism, impaired signal transduction, mitochondrial unfolded protein response, and endoplasmic reticulum stress. Aberrant mitochondrial fission is an early marker of mitochondrial injury and cardiomyocyte apoptosis, whereas reduced mitochondrial fusion is frequently observed in stressed cardiomyocytes and is associated with mitochondrial dysfunction and cardiac impairment. Mitophagy is a protective, selective autophagic degradation process that eliminates structurally compromised mitochondria, preserving mitochondrial network integrity. However, dysregulated mitophagy can exacerbate cellular injury, promoting cell death. Beyond their role as the primary energy source of the cell, mitochondria are also central regulators of cardiomyocyte survival, mediating apoptosis and necroptosis in reperfused myocardium. Consequently, MQC impairment may be a determining factor in cardiomyocyte fate. This review consolidates current insights into the regulatory mechanisms and pathological significance of MQC across diverse cardiovascular conditions, highlighting potential therapeutic avenues for the clinical management of heart diseases. Graphical Abstract Healthy cardiomyocytes feature a precise balance between mitochondrial fusion (mediated by MFN1/2 and Opa1) and division (mediated by Drp1). Fusion contributes to mitochondrial network stability and functional restoration, while division ensures mitochondrial renewal and the removal of damaged parts. PGC-1α, NRF1/2 and TFAM regulate mitochondrial biogenesis to ensure mtDNA transcription and replication and maintain mitochondrial quantity and quality. Mitochondrial autophagy selectively removes damaged mitochondria through LC3II, FUNDC1, PINK1-Parkin, and other molecular pathways to prevent the accumulation of cell damage. The cell begins to undergo a series of stress responses when the balance between mitochondrial fusion and division is disrupted or biogenesis and autophagy are impaired. Initially, BAX activates caspase-9, initiating the apoptosis pathway, leading to the activation of caspase-3 and cell death. If mitochondrial damage is aggravated, RIPK3 activates MLKL, which triggers necroptosis through CAMKII mediation, leading to cell structure destruction and loss of function. The interactions between mitochondrial fusion and division, biogenesis and autophagy were demonstrated, and the specific mechanisms of how these processes progressively affect cardiomyocyte survival are described. MFN1/2: mitofusin 1 and 2; Opa1: optic atrophy protein 1; Drp1: dynamin related protein 1; FUNDC1: Fun14 domain-containing protein 1; PINK1: PTEN induced putative kinase 1; RIPK3: receptor-interacting protein kinase 3; MLKL: mixed lineage kinase domain-like protein; CAMKII: Ca2+-calmodulin-dependent protein kinase II.