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.
In the USA, cardiology is a part of internal medicine. It is a discipline which includes the diagnosis, treatment, causes, as well as research into heart diseases and injuries.
In the USA, to become a cardiologist you have to complete a three-year residency in internal medicine, and then a three-year residency in cardiology.
Cardiology has several subspecialties
- 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).
A brief history of cardiology
- 1628 - William Harvey (15878-1657), an English doctor, was the first to describe the systemic circulation and properties of blood that is pumped throughout the body by the heart. Ibn al-Nafis had mentioned blood circulation in a rudimentary way in a commentary in Avicenna's Canon in 1241.
- 1706 - Raymond de Vieussens (1635-1715), a French anatomy professor, described the structure of the chamber and vessels of the heart. He is remembered for his research in cardiology, and his anatomical studies of the spinal cord, brain and heart. He is credited with being the first doctor to describe the left ventricle in the heart accurately, as well as some blood vessels.
- 1733 Stephen Hales,(1677-1761), a clergyman whose scientific contributions in the fields of botany, pneumatic chemistry and physiology were considerable. He invented the surgical forceps for removing bladder stones, and a type of ventilator. He was also the first person to measure blood pressure.
- 1816 - René-Théophile-Hyacinthe Laennec (1781-1826) a French doctor, invented the stethoscope and pioneered its use in diagnosing a number of chest infections. In 1826 Laennec died of TB.
- 1903 - Willem Einthoven, a Dutch physiologist and doctor, developed the electrocardiograph (ECG or EKG). In 1924 he received the Nobel Prize or Medicine.
- 1912 - James Bryan Herrick (1861-1954), an American doctor, described the signs and symptoms of heart disease, explaining that it is caused by the hardening of the arteries.
- 1938 Robert E. Gross (1905-1988), an American surgeon and a medical researcher, performed the first ever heart surgery.
- 1951 - the first artificial heart valve was created. A plastic valve to repair an aortic valve was developed by Charles Hufnagel (1916-1989), a US surgeon.
- 1952 - the first open heart surgery was performed by F. John Lewis, an American surgeon.
- 1953 - the first mechanical heart and blood purifier was used by Dr. John H. Gibbon (born 1929)
- 1961 - first time external cardiac massage was used to restart a heart. The procedure was perormed by J. R. Jude and team at Johns Hopkins University.
- 1965 - mechanical devices were implanted by Micahel DeBakey and Adrian Kantrowitz to help a diseased heart.
- 1967 - a whole heart transplant from one human to another was performed for the first time by Christiaan Barnard, a South African surgeon.
- 1982 - a permanent artificial heart was implanted into a patient by Willem DeVries, a US surgeon. The medical device was designed by Robert Jarvik, a US physician.