Electrocardiography is the technique by which the electrical activities of the heart are studied. The spread of excitation through myocardium (the heart muscle) produces a local electrical potential. This causes the flow of small currents through the body, which acts as a volume conductor. These small currents can be picked up from the surface of the body by using suitable electrodes and recorded in the form of the electrocardiogram. This technique was discovered by Dutch physiologist Einthoven Willem, who is considered the father of the ECG.
An electrocardiograph is an instrument by which the electrical activities of the heart are recorded. An electrocardiogram is a record or the graphical registration of electrical activities of the heart, which occur prior to the onset of mechanical activities. It is the summed electrical activity of all the cardiac muscle fibers recorded from the surface of the body. The electrocardiogram is recorded in 12 leads. The electrodes are fixed on the limbs. Usually, right arm, left arm, and left leg is chosen. The heart is said to be in the center of an imaginary equilateral triangle drawn by connecting the roots of these three limbs. This triangle is called Einthoven’s triangle. The electrical potential generated from the heart appears simultaneously on the roots of these three limbs.
The electrocardiogram has great application in cardiovascular physiology, and the heart health as a whole. This book, which can be listened to in less than 24 hours will furnish you with the skills you need to totally crush ECG and its interpretation. With it, you can successfully tackle NCLEX at first sitting!