1628:
William Harvey, United Kingdom, published his thesis that the heart pumped blood around the body.
1791:
In Italy, Luigi Gamvani discovered that electrical stimulation of frogs hearts lead to contraction of the cardiac muscle.
1820:
On the 16th of September Schweigger invented the galvanometer which was the basis of the modern day ECG machine.
1887:
First human electrocardiogram was recorded.
1893:
In Holland, Willem Einthoven (1860 - 1927) introduced the term electrocardiogram (ECG).
1895:
Willem Einthoven distinguished five deflections (PQRST).
1901:
Willem Einthoven constructed the first electrocardiograph, it weighed 270kg, occupied two rooms and required 5 people to operate it.
1905:
First ECG transmitted from hospital to the laboratory 1.5km away via a telephone cable.
1906:
Willem Einthoven published the first normal and abnormal ECG.
1920:
First ECG of an acute myocardial infarction by Harold Pardee in the USA.
1924:
Willem Einthoven won the Nobel prize for his work with ECG's.
1931:
Frank Wilson, USA, described the concept of a unipolar system that could record the activity of the heart from anywhere on the body.
1938:
The American Heart Association and the Cardiac Society of Great Britain defined the standard position of the chest leads and called them V1 - V6.
1942:
Emmanual Goldberger was able to increase Wilsons voltages by 50% and the leads then became known as aVR, aVL and aVF (where 'a' means augmented).
Present Day:
The 12 Lead ECG has become one of the most common cardiac investigations which is important in acute and long term care.
Whilst the ECG is often performed in an emergency situation, it is also a common procedure in primary and continuing care. The ECG is one of the most basic, noninvasive investigations in medicine and is an important tool in cardiology. It is perhaps the most useful in the detection and identification of irregular heart rhythms. It is also a major tool in the diagnosis and treatment of heart attacks and other forms of heart disease. Other indications include:
The ECG represents electrical changes associated with contraction of the heart tissue.
The 12 lead ECG displays 12 different views of the heart's electrical activity and is composed of 12 leads which is obtained by 10 electrodes connected to the body in a standardised pattern.
The ECG machine is a complex piece of equipment and it is essential that it is checked and maintained on a regular basis. There are a variety of machines available in practice. For servicing and maintenance of equipment, please refer to the manufacturers instructions.