[Quantifying the amplitude of microvolt T wave alternans with sparse principal component analysis].

T wave alternans in ECG is an important prediction factor for a sudden death. It is crucial in clinic to quantify the amplitude of T wave alternans. However, T wave alternans are highly non-stationary, which makes accurate quantification very difficult. In this study, we proposed a new method to improve the amplitude quantification. We identified T wave alternans by principal component analysis (PCA) with statistical test, and processed the principal components with T wave alternans further by imposing sparse constraint. We evaluated and compared our method against other 4 popular solutions on an international benchmark database. The results including rank correlation coefficient and relative error indicate that this sparse principal component (SPC) based method is better than others.