Recommendations for the Standardization and Interpretation of the Electrocardiogram

Abstract

Abstract-This statement examines the relation of the resting ECG to its technology. Its purpose is to foster understanding of how the modern ECG is derived and displayed and to establish standards that will improve the accuracy and usefulness of the ECG in practice. Derivation of representative waveforms and measurements based on global intervals are described. Special emphasis is placed on digital signal acquisition and computer-based signal processing, which provide automated measurements that lead to computer-generated diagnostic statements. Lead placement, recording methods, and waveform presentation are reviewed. Key Words: AHA Scientific Statements Ⅲ electrocardiography Ⅲ computers Ⅲ diagnosis Ⅲ electrophysiology Ⅲ intervals Ⅲ potentials Ⅲ tests I n the century since the introduction of the string galvanometer by Willem Einthoven, 1 the electrocardiogram (ECG) has become the most commonly conducted cardiovascular diagnostic procedure and a fundamental tool of clinical practice. 2,3 It is indispensable for the diagnosis and prompt initiation of therapy in patients with acute coronary syndromes and is the most accurate means of diagnosing intraventricular conduction disturbances and arrhythmias. Its interpretation may lead to the recognition of electrolyte abnormalities, particularly of serum potassium and calcium, and permit the detection of some forms of genetically mediated electrical or structural cardiac abnormalities. The ECG is routinely used to monitor patients treated with antiarrhythmic and other drugs, in the preoperative assessment of patients undergoing noncardiac surgery, and in screening individuals in high-risk occupations and, in some The American Heart Association, the American College of Cardiology, and the Heart Rhythm Society make every effort to avoid any actual or potential conflicts of interest that may arise as a result of an outside relationship or a personal, professional, or business interest of a member of the writing panel. Specifically, all members of the writing group are required to complete and submit a Disclosure Questionnaire showing all such relationships that might be perceived as real or potential conflicts of interest. Copies: This document is available on the World Wide Web sites of the American Heart Association (www.americanheart.org) and the American College of Cardiology (www.acc.org). A single reprint is available by calling 800-242-8721 (US only) or writing the American Heart Association, Public Information, 7272 Greenville Ave, Dallas, TX 75231-4596. Ask for reprint No. 71-0389. To purchase additional reprints, call 843-216-2533 or e-mail kelle.ramsay@wolterskluwer.com.Permissions: Multiple copies, modification, alteration, enhancement, and/or distribution of this document are not permitted without the express permission of the American Heart Association. Instructions for obtaining permission are located at http://www.americanheart.org/presenter.jhtml? Identifierϭ4431. A link to the "Permission Request Form" appears on the right side of the page.© 2007 American...

Fine Tuning of the Dynamic Low-pass Filter for Electromyographic Noise Suppression in Electrocardiograms

“…It is designed in compliance with the new low-pass filtering recommendations for cutoff [4]. The computational cost depends on the sampling frequency.…”

“…Setting the low-pass filter of the ECG to a lower cutoff level eliminates not only the muscle noise but also the clinically significant highfrequency components of the signals inside the QRS complex [1], J-waves and pacemaker spikes [2]. For that reason, in 2007, the American Heart Association (AHA) changed its low-pass filter recommendations from 35 Hz cutoff in 1967 [3] to 150 Hz for adolescents and adults and to 250 Hz for children [4].…”

The Shortest QRS Duration of an Electrocardiogram Might Be an Optimal Electrocardiographic Predictor for Response to Cardiac Resynchronization Therapy

“…Electrocardiographic analysis: Standard 12-lead ECGs were acquired at a speed of 25 mm/s and a scale of 10 mm/mV. 19) The QRS durations from the 12 leads of each ECG were measured. The QRS duration is measured from the beginning of the Q wave to the end of the S wave by moving the calipers based on the software incorporated in the ECG recording equipment (MUSE system, General Electric, USA) ( Figure 1).…”

Current Methods of Ambulatory Electrocardiogram Monitoring. Technical Aspects

“…Создание транзисторов, появление возможности осуществления записи на магнитные носители и отображения ЭКГ-сигнала на дисплее привели в 1952 г. к уменьшению массы габаритов прибора. На момент становления ме-тодики требования к холтеровскому монитору включа-ли в себя: длительность регистрации сигнала -не менее 24 ч, 2-3 ЭКГ-канала, частотный диапазон -не менее 0,5-40,0 Гц, частота дискретизации -125 Гц и выше, разрешающая способность -не ниже 5-20 мкВ; пре-образование ЭКГ-сигнала было аналого-цифровым [7].…”