Cardiac densification insufficiency may cause weakness in the extremities. Myocardial densification insufficiency is a cardiomyopathy. It is characterized by the presence of abnormally large myofibrillar trabeculae and interlocking deep saphenous fossae within the ventricles, primarily involving the left ventricle. The trabecularized myocardium of the ventricle leads to perfusion derangement within the ventricular wall, making the myocardium insufficiently supplied with blood, thus causing heart failure, resulting in diminished pumping function of the heart, and further leading to symptoms of peripheral ischemia and hypoxia, which may then cause weakness in the extremities. Other clinical manifestations of myocardial densification insufficiency are arrhythmias, mostly fatal ventricular arrhythmias such as ventricular tachycardia. It can also cause endocardial thrombosis, and dislodged thrombus can cause embolism in the physical circulation. When the diagnosis of myocardial densification insufficiency is confirmed, it is recommended to consult the doctor in time and carry out standardized treatment under the guidance of the physician, do not do it on your own to avoid adverse consequences.