What is an EKG?
What does that durned squiggle mean?
The basics: The heart generates electrical signals. By the movement of sodium, potassium and calcium through regulated channels, the voltage of a cell is manipulated. Myocytes form a syncytium so that the changes in voltage of one cell can trigger changse in the potentials of a nearby cells. In this way, autorhythmic portions of the heart (and in normal, healthy myocardium, the most notable area is the sinus node) can generate signals (changes in potentials) that cause the heart to contract in an organized and functionally useful manner.
The EKG (or anglicized ECG) is no more than a means of sensing, and transducing these electrical signals or potential changes into a seemingly meaningless squiggle that terrifies any newcomer to EKG reading. Well, maybe it's more accurate to say intimidates than terrifies. I believe that you can be a fair diagnostician by learning all of the criteria for normal and abnormal findings on an EKG, but to never understand what that squiggle really means will hold you back from being a EKG whiz.
