All cardiologists in the branch of medicine study the disorders of the heart, but the study of adult and child heart disorders each require different training pathways. Therefore, an adult cardiologist (often simply called “cardiologist”) is inadequately trained to take care of children, and pediatric cardiologists are not trained to treat adult heart disease.
Surgical aspects are not included in cardiology and are in the domain of cardiothoracic surgery. For example, coronary artery bypass surgery (CABG), cardiopulmonary bypass and valve replacement are surgical procedures performed by surgeons, not cardiologists. However, some minimally invasive procedures such as cardiac catheterization and pacemaker implantation are performed by cardiologists who have additional training in non-surgical interventions (interventional cardiology and electrophysiology respectively).
Clinical cardiac electrophysiology is a branch of the medical specialty of cardiology and is concerned with the study and treatment of rhythm disorders of the heart. Cardiologists with expertise in this area are usually referred to as electrophysiologists. Electrophysiologists are trained in the mechanism, function, and performance of the electrical activities of the heart. Electrophysiologists work closely with other cardiologists and cardiac surgeons to assist or guide therapy for heart rhythm disturbances (arrhythmias). They are trained to perform interventional and surgical procedures to treat cardiac arrhythmia
Adult congenital heart disease
As more children with congenital heart disease are surviving into adulthood, a hybrid of adult & pediatric cardiology has emerged called adult congenital heart disease (ACHD). This field can be entered as either adult or pediatric cardiology. ACHD specializes in congenital diseases in the setting of adult diseases (e.g., coronary artery disease, COPD, diabetes) that is, otherwise, atypical for adult or pediatric cardiology.