When any person gets chest pain or any heart-related problems, a doctor’s first suggestion would be “Let’s get you an ECG Test ”.
Immediately a question may arise in the mind - What is an ECG?
Let us understand What is ECG then,
ECG is a graphical representation of the electrical activity of the heart over a period of time.ECG measures how the activity of the heart changes in accordance with time. ECG shows the electrical differences of the heart when electrical depolarization and repolarization occurs.
ECG Wave Form
ECG Graph is recorded in Time Versus Voltage Graph and measurings units are seconds and millivolts.
The below diagram shows electrode placements.
The above Diagram shows the placements of electrodes for measuring ECG. A negative electrode placed on the right wrist, a positive electrode placed on the left ankle and then the desired graph is obtained.
As shown in the Diagram. P-R interval measured from the starting of the P Wave and up to the beginning of the QRS Complex. During the S-T Segment, ventriculars are completely depolarized.
Q-T interval is measured from the beginning of the QTS complex and up to the end of the T wave.
The invention of electrocardiographs leads to advancement in the field of Cardiology. Electrocardiography provided an opportunity to understand the working of a healthy heart and also a diseased heart, History of the ECG dates back to 1842. In the year 1842 Italian physicist Carlo Matteucci showed that each heartbeat accompanies electrical current. In the year 1856 Rudolph yon Koelliker and Heinrich Miller recorded cardiac action potential with the help of Galvanometer. In the year 1870s y Gabriel Lippmann recorded the first ECG. The Next major breakthrough was in the year 1901, In that year String Galvanometer invented by Willem Einthoven, as shown in the below figure. He used String Galvanometer to record ECG. In 1912 He gave another contribution to Cardiology, He gave Einthoven's triangle approach to record ECG. He was awarded Nobel in the year 1924.
The ECG crossed a long way since Einthoven's String Galvanometer. Use of Computers for Screening the ECG reading begins in the year 1960s. Computer-Based Clinical analysis of ECG has begun in the 1970s. The present form of the ECG instrument has shown below.
These are alarming situation’s and one should not avoid such symptoms, because
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