Evaluation of a sudden cardiac death indicator using linear approximation and curves alignment

Abstract

Ventricular Late Potentials make QRS complexes larger, that is why many algorithms are based on quantifying increases in the QRS complex duration. These elongations generate misalignments in the QRS, resulting in practice; the averaged algorithm considers the ECG components, including those VLPs, as well as random variables. We recorded High Resolution ECGs (HRECGs) from 50 subjects in resting position with no heart-stroke antecedents. VLPs were simulated added to the HRECGs, and then two cases were evaluated: (1) duration of the QRS complexes with VLPs without QRS-alignment, and (2) duration of QRS complexes with VLPs using time- and amplitude- QRS-alignment. When using amplitude- and time-alignment it is possible to reach a sensitivity of 0.96 and a specificity of 0.52, as opposed to 0.72 and 0.40, respectively, when using only SAECG without QRS-alignment.