A Cardiologist is an internist with super-specialized training in diagnosing and managing cardiovascular disease. All cardiologists will have basic training in diagnosing and treating these diseases using unusual techniques such as stress testing, ultrasound, and nuclear techniques. A large amount will also be able to perform cardiac catheterization, which includes performing coronary Angiography, balloon angioplasty and placement of stents to the arteries to the heart, as well as other organs. In some cases, cardiologists may refer patients for surgical procedures, including open-heart surgery valve replacement and Surgical procedures for congenital heart defects.