Myocardial densification insufficiency is not a terminal disease and can last for many years asymptomatically, but it can also lead to severe heart failure and death at an early stage, for which there is no effective treatment and symptomatic management is the mainstay. Myocardial densification insufficiency (NVM) refers to a genetically related hereditary cardiomyopathy characterized by deep crypt fossae interspersed within the ventricles and abnormally thick trabeculae. The etiology and pathogenesis of NVM are unclear, and it may be caused by the cessation of the process of myocardial densification in the embryonic period, which is associated with genetic variants. The first symptoms of NVM often appear in adulthood, with progressive arrhythmias, systemic thromboembolism, and cardiac dysfunction as the main clinical manifestations. Some patients may die of severe heart failure at an early age, which may be related to the extent of the nondensified myocardium and the degree of chronic ischemia. There is no standardized protocol for the treatment of patients with NVM, which focuses on the treatment of arrhythmias, heart failure, and comorbid cardiac malformations, with prophylactic anticoagulation in the presence of atrial fibrillation and other thrombotic risks. Surgery can be performed when combined with other congenital heart disease, and the only option for patients with severe NVM in the end stage is heart transplantation. Early diagnosis and intervention of NVM can help prolong the patient’s life and should be treated aggressively in the hospital.