Cardiology is the study and treatment of disorders of the heart; it is a medical specialty which is involved in the care of all things associated with the heart and the arteries. A cardiologist is not the same as a cardiac surgeon - the cardiac surgeon opens the chest and performs heart surgery, a cardiologist, on the other hand, carries out tests and procedures, such as angioplasty.
Heart disease differs from cardiovascular disease, in that the latter refers to disorders and illnesses of the heart and blood vessels, while the former is only concerned with the heart.
Nuclear Cardiology - using nuclear imaging techniques in the non-invasive study of cardiovascular disorders and diseases, including infarction imaging, SPECT (single-photon-emission computed tomography), planar imaging, and myocardial perfusion imaging. The nuclear cardiologist uses radioactive materials.
Interventional Cardiology - involves the use of intravascular catheter-based techniques with fluoroscopy to treat congenital cardiac, valvular and coronary artery diseases.
Interventional cardiologists may perform angioplasties, valvuloplasties, congenital heart defect corrections, and coronary thrombectomies.
Echocardiography - the use of ultrasound waves to create images of the heart chambers, valves and surrounding structures. Echocardiography can measure how well the heart is pumping blood (cardiac output), as well as determining levels of inflammation around the heart (pericarditis). Echocardiography can also be used to identify structural abnormalities or infections of the heart valves.
Cardiac electrophysiology - the study of the mechanism, spread, and interpretation of the electric currents which occur inside heart muscle tissue - the system that generates the heart beat.
During an electrophysiology study (EPS) of the heart, catheters are threaded into a vein at the top of the leg; guided under fluoroscopy, the catheter makes its way to the heart. The catheters measure the electrical signals within the heart. EPS of the heart may be performed to determine whether the patient needs a pacemaker, why somebody is fainting if other tests have found no cause, and to help decide the best treatment for patients with arrhythmia (abnormal heart rhythm). EPS may also determine how prone a patient is to tachycardia (accelerated heart beat).