Essay by PaperNerd ContributorCollege, Undergraduate November 2001

download word file, 5 pages 0.0

Downloaded 23 times

To understand the electrocardiograph, otherwise known as the "ECG" or "EKG", one must first get to know the human heart. Most people know that the electrocardiogram measures the electrical impulses of the heart, but have no idea of how or why the heart produces these impulses and what they mean. Next, a brief history of the events that led up to the invention of the electrocardiograph is in order. It is always insightful to delve into the thought processes and/or events that resulted in the formation of the tools used in present day. Upon completing these two exercises, one can move on to the details surrounding the electrocardiograph itself. Only then, will there be an appreciation of the important function it serves and a true understanding of how it works.

The human heart is in actuality a four-chambered pump for the circulatory system. The ventricles perform the main pumping function of the heart.

The atria are blood storehouses while the ventricles are pumping. This resting/filling phase is called the "diastole". The contractile, or pumping, phase is called "systole". A series of electrical events take place in the heart during both of these phases. A specific pattern of electrical activation in the musculature of the atria and ventricles causes the contraction of these structures. The electrical activation patterns are initiated by a coordinated series of events that take place in the "specialized conduction system" of the heart, which is very small in comparison to the total mass of the heart. Several different types of tissue make up the heart: SA and AV nodal tissue, atrial, Purkinje, and ventricular. Each tissue is electrically excitable and exhibits different characteristics which makes their rhythm distinguishable in measurement. Each heartbeat of the normal human heart originates in the SA node. A normal heart...