It is a branch of science that deals with the diagnosis and treatment of diseases that occur in the hearts and partly in the circulatory system of children, starting from the womb until the age of 18. They also undertake the prevention of heart diseases in risk groups. The cardiovascular system is one of the first organs that begin to develop in the womb. It begins to form in the form of a tube in the third week, and at about two months of age, it regains its shape almost similar to that at birth and begins a process of uninterrupted functioning. This process does not always work perfectly and some problems occur. These structural and rhythm-related problems affect approximately one in every hundred live-born babies (0.8-0.9%). With the development of technology, it has become possible to detect these problems. Detecting and managing these problems, which can also be diagnosed in the womb, is a team effort;