Electrocardiography

Background

An electrocardiogram (EKG) is a noninvasive test that provides a visual representation of the electrical conduction of the heart. It is called EKG because the test produces a “-gram” (something written or drawn—e.g., telegram, diagram—the “G”) of the electrical (the “E”) conduction through the heart (cardio—the “K” or “C”). The abbreviation ECG can be used interchangeably with the more common EKG, a reflection of the original Dutch spelling of “electrokardiogram.” There are different types of EKGs, but one of the most common is the 12-lead EKG, named so because the conduction is visualized in 12 directions, or vectors, in space. The 12-lead EKG is the primary focus of this chapter.