TY - CHAP M1 - Book, Section TI - Electrocardiography A1 - Goldberger, Ary L. A2 - Loscalzo, Joseph A2 - Fauci, Anthony A2 - Kasper, Dennis A2 - Hauser, Stephen A2 - Longo, Dan A2 - Jameson, J. Larry PY - 2022 T2 - Harrison's Principles of Internal Medicine, 21e AB - An electrocardiogram (ECG or EKG) is a graphical representation of electrical activity generated by the heart. The signals, detected by means of metal electrodes attached to the extremities and chest wall, are amplified and recorded by the electrocardiograph device. ECG leads (derivations) are configured to display the instantaneous differences in potential between specific pairs of electrodes. The utility of the ECG derives from its immediate availability as a noninvasive, inexpensive, and highly versatile test. In addition to its use in detecting arrhythmias and myocardial ischemia, it may reveal findings related to life-threatening metabolic disturbances or to increased susceptibility to sudden cardiac arrest (see also Chaps. 306 and 408). SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1190520693 ER -