History of the Heart, EKGs4U
EKG, or ECG, stands for electrocardiogram. It is a machine or “voltmeter” which reads electrical energy from the body. Some of the first EKG machines, called string galvanometer, were bulky, table sized apparatus built about 1895.
Today’s units are compact, light weight and placed on carts which can be wheeled to any location in the hospital. One of the biggest and best improvements on the early machines came with the invention of the electrode, the part that conducts the heart’s electrical activity to the machine. In the early 1900’s, hands and feet were placed In sodium chloride baths as a means of conducting the electrical currents from the body. But, by the 1940’s metal disks with leads were strapped to wrists and ankles. Now, the lead wires are attached to disposable patches which are self-adhesive. The electrocardiogram is still the basic cardiologic test and is widely applied to patients with suspected or known heart disease and as a basic reference for most other cardiologic tests.
The EKG machine receives electrical impulses from the body and changes them into a monitor tracing that can be analyzed to find problems with electrical conduction in the heart. The EKG machine simply picks up electrical impulses: it does not read mechanical activity.
Sometime in the 19th century it became known that electricity was generated from the heart. Augustus Waller working in London during the early 1900’s was the first to look at the heart from an electrical standpoint, but didn’t see much in the clinical applications. The break through came when Willem Einthoven invented the string galvanometer in The Netherlands. This device turned out to
be a lot more precise in its applications then that of Waller’s. In 1924, W. Einthoven won the Nobel Prize for his invention, the EKG machine.