A cardiologist is a physician who has specialty training in the area of cardiology. Cardiologists are often MD trained, and typically had general training in internal medicine (or pediatrics if a pediatric cardiologist) prior to the completion of cardiology fellowship. Cardiologists are often confused with cardiac or cardiothoracic surgeons, who primarily perform operations on the heart. A “board-certified cardiologist” is a physician who trained in cardiology, met minimum training requirements, and also passed the cardiology board exams. After cardiology fellowship, physicians can choose to undergo additional training in a subspecialty of cardiology (e.g., echocardiography, nuclear cardiology, intervention, etc.).