In recent years, with the large-scale use of plastic products, the degree of plastic pollution has increased, becoming a serious global problem. Microplastics and nanoplastics (MNPs), as emerging environmental pollutants, are widely found in organisms and the environment. These plastic particles enter the human body through 3 exposure pathways: breathing, the food chain’s bioaccumulation and transfer, and skin contact, thereby exerting toxic effects. The physical attributes of MNPs, including their shape, size, and surface characteristics, are not static but rather undergo dynamic transformations in response to changing environmental conditions. These changes can significantly influence their behavior and interactions within different ecosystems. When considering MNPs as carriers of chemicals, two primary mechanisms can be distinguished. (1) MNPs have the capacity to adsorb pollutants from their surrounding environment. These pollutants may encompass a wide range of substances, such as heavy metals, organic compounds, and other contaminants that are commonly found in water, soil, or air. (2) MNPs may also carry chemical agents that are artificially introduced during their commercial production process. For example, flame retardants and pigments are often added to plastics to enhance their performance or appearance. These artificially added chemicals can remain associated with MNPs throughout their lifecycle and may contribute to their overall toxicological impact. Cardiovascular diseases (CVDs) are a general term for diseases of the heart, arteries, veins, and capillaries, and are one of the main causes of disability and death. CVDs have higher incidence, mortality, and recurrence rates, and more complications, which reduce the quality of life and happiness of patients, the phenomenon is gradually showing a trend of early onset, therefore early-stage prevention for CVDs is of critical importance. This article reviews the properties of MNPs and their potential threats to the cardiovascular system, aiming to explore how MNPs cause CVDs through certain physiological effects, toxicity mechanisms, and related pathways. Our review primarily focus on elucidating several critical mechanisms through which MNPs exert their adverse effects. Specifically, the review examines how the enhancement of oxidative stress can trigger the expression of pro-inflammatory factors, which in turn leads to the formation of a chronic inflammatory microenvironment within biological systems. Additionally, MNPs possess the capacity to adsorb toxic metals and organic substances from their surroundings. Furthermore, the review summarizes that sewage irrigation and atmospheric deposition are significant factors contributing to the co-pollution of heavy metals with MNPs in environmental settings. The interaction between heavy metals and MNPs has been shown to have detrimental effects on agricultural productivity, as it can inhibit crop growth and simultaneously increase the absorption rate of heavy metals in plants. When these contaminated plants enter the food chain, the accumulated heavy metals can ultimately be ingested by humans. This process poses a potential risk for inducing acute coronary syndrome and other CVDs, thereby underscoring the importance of understanding and mitigating the impact of MNPs on human health. In addition, our review also gives examples of the long-term effects of MNPs on cardiovascular function and the adverse consequences such as arrhythmia and atherosclerosis, the limitations of the current studies of MNPs affecting cardiovascular system health and future directions are also explored.