Infective endocarditis is an inflammation of the endocardium of the heart valves or ventricular wall due to direct infection by bacteria, fungi, or other microorganisms (e.g., viruses, rickettsia, chlamydia, spirochetes, etc.), which may be accompanied by the formation of superfluous organisms. The redundant organisms are platelet and fibrin clumps of varying size and shape, containing a large number of microorganisms and a small number of inflammatory cells. There are two main types of infective endocarditis: one is “autologous valve endocarditis”, which occurs in an autologous heart valve. Most of these patients have underlying cardiac pathology, such as ventricular septal defect, patent ductus arteriosus, or stenosis or incomplete closure of the valve. There is also “prosthetic valve infective endocarditis” or “implant-associated endocarditis,” which occurs in patients with intracardiac implants, most of which are intracardiac implants such as prosthetic valves, pacemakers, and prosthetic patches. In addition, depending on the urgency of the onset of the disease, it can be divided into “acute infective endocarditis” and “subacute infective endocarditis”. Infective endocarditis clinical manifestations: 1. fever Fever is the most common manifestation of endocarditis patients, holding such patients often show repeated fever, some fever may be preceded by chills, body temperature can be high, long history of disease, temperature can be repeatedly increased, the general anti-infective treatment is not effective. 2, embolic manifestations Some patients with endocarditis have peripheral vascular embolism as the first manifestation, and some patients even have acute cerebral infarction as the first manifestation, with serious consequences. This is caused by the detachment of intracardiac redundant organisms, which can also manifest as mesenteric artery embolism, splenic infarction, etc. 3.Heart murmur Heart murmur may appear when endocarditis causes valve insufficiency. 4.Lethargy Repeated fever, cardiac structural damage causing cardiac insufficiency, etc., can be manifested as weakness, and in severe cases, heart failure: such as shortness of breath, wheezing, inability to lie down, edema, etc. 5. Positive blood culture Patients with endocarditis often have positive blood culture when the infection is poorly controlled.