Cardiovascular disease (CVD) is a leading global cause of death and strains healthcare systems significantly. Early diagnosis is crucial and can be achieved through cardiac biomarker assessment, which enables timely treatment and reduces mortality rates. Traditional diagnostic methods require large hospital equipment for electrocardiography and laboratory analysis, leading to lengthy procedures. To address this, there is increasing interest in advanced biosensing technologies for rapid CVD marker screening. Advances in nanotechnology and bioelectronics have led to new biosensor platforms that offer rapid detection, accurate quantification, and continuous monitoring. This comprehensive review focuses on blood-based RNA cardiac biomarkers, which are widely used in clinical settings, and examines the development of electrochemical nanobiosensors for detecting RNA biomarkers. It provides a thorough evaluation of the benefits and drawbacks of these biosensing devices and offers insights into future research directions for electrochemical nanobiosensors in CVD, particularly those based on RNA markers.