Signal averaged ECG

Abstract

The signal averaged electrocardiogram (SAECG) is one of several proposed methods for noninvasive risk stratification for sudden cardiac death (SCD). The term SAECG refers to techniques improving the signal-to-noise ratio, thus allowing analysis of signals that are too small to be detected by routine measurement. Among such signals are those arising from areas of slow and inhomogeneous conduction in diseased ventricular myocardium, which may represent a substrate for malignant reentrant ventricular tachyarrhythmias. A recently published AHA/ACC/HRS Consensus Document acknowledged that an abnormal SAECG may identify patients with prior myocardial infarction at risk of SCD. Given its high negative predictive accuracy, the SAECG could be useful for identification of low-risk patients. However, the document noted that routine use of the SAECG to identify patients at high risk for SCD is not adequately supported by existing data and further studies would be required to assess the utility of this test. It is possible that improved risk stratification may be accomplished if the SAECG is utilized as part of an algorithm in conjunction with other risk stratifiers. Large prospective studies to develop a robust prediction model are still warranted.