An ECG machine is used for graphically recording and monitoring the electrical activity of various phases of heart beat. This is done with the help of electrodes externally attached to the outer surface of skin, on the chest and limbs of patients with heart diseases. It enables monitoring the functions of heart accurately in a very short span of time, there by helping in efficient diagnosis and treatment of heart related problems.
Functions of ECG machine involve recording of the heart beats of patients being examined in the form of waves on a graphic paper. These waves are known as ECG waves. Each electrical stimulus takes the shape of a wave and patterns are formed on the paper with inter related waves. The graphic ECG paper is made up of small squares of 1mm. A standard ECG prints 25 such small squares per second. So duration of a particular wave is easily calculated in a given time span. 10 small squares vertically equal to one mille volt. In this way, amount of voltage released by heart is also measured. If the graph is flat at any time without waves, it means no electrical activity is happening at that particular moment.
To understand the functioning of ECG machine, one needs to be aware of the basic functions and working of heart. Heart is composed of four chambers making up two pumps. The right pump receives blood from the body and pumps it to the lungs. The left pump gets blood from the lungs and pumps it to other parts of the body. Each pump has two chambers Atrium and Ventricle. Atrium collects the blood and sends it to the ventricle. On contraction of ventricle, blood is pumped from the heart to the body.
Electrical impulses created in the pacemaker region of right atrium cause contraction, thereby pushing the blood to ventricle. When the impulse moves to the ventricle, it causes contraction in ventricle and pushes blood away from the heart. Soon as the impulse moves away from heart, it relaxes. These electrical impulses flowing in the body can be measured from the body surface in the form of electrical currents at specific areas. ECG machine reads these currents with the help of electrodes attached to the skin of the body.
Each heart beat produces three different pulses of ECG waves. The first pulse is known as P wave and represents the electrical signal produced by pacemaker. The second is a larger signal and called QRS complex which represents the signals created by relaxation of atrium and contraction of ventricle. The last one of the cycle is called the T wave which represents relaxation of ventricle. The heart sound represents this compound of QRS complex and T waves.
An ECG machine is capable of capturing and recording all these functions of the heart in a graphical form enabling accurate diagnosis and treatment of functions of the heart. By studying the movements of these ECG waves depicted by ECG machines, doctors can easily study the heart beat variations. This helps them in locating the defects of heart functions and thereby to prescribe the correct treatment.
ECG machine is safe and easy to use as and when required without requirement of any elaborate arrangement. Further, it is very economical for the patient to have ECG reports.