Cardiology is a branch of medicine dealing with disorders of the human and animal heart. Medical diagnosis and treatment of heart failure, valvular heart disease, congenital heart defects, coronary artery disease,and electrophysiology are subjects of this field. Doctors specialized in this field are called cardiologists, a specialty of internal medicine. Pediatric cardiologists are pediatricians who specialize in cardiology. Physicians who specialize in cardiac surgery are called cardiothoracic surgeons or cardiac surgeons. The latter should not be confused with cardiologists since it is a specialty of general surgery.