RT Book, Section A1 Goldberger, Ary L. A2 Jameson, J. Larry A2 Fauci, Anthony S. A2 Kasper, Dennis L. A2 Hauser, Stephen L. A2 Longo, Dan L. A2 Loscalzo, Joseph SR Print(0) ID 1157018608 T1 Electrocardiography T2 Harrison's Principles of Internal Medicine, 20e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781259644016 LK accesspharmacy.mhmedical.com/content.aspx?aid=1157018608 RD 2024/03/28 AB An electrocardiogram (ECG or EKG) is a graphic 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. 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. 299 and 401).