Average T-wave alternans activity in ambulatory ECGs

T-wave alternans (TWA) is considered as an index of susceptibility of sudden cardiac death (SCD). The utility of TWA testing during ambulatory monitoring is being increasingly studied. A common approach for ambulatory TWA testing is to quantify the maximum amplitude of TWA in an ECG record, which requires visual verification of the results to discard erroneous measurements due to noise or artifacts in the ECG. This work presents a fully-automated method to quantify the average TWA activity in ambulatory ECGs. Our results indicate that quantifying the average TWA activity instead of the maximum TWA amplitude allows the prediction of SCD in in patients with chronic heart failure (CHF).