Noise processing in exercise ECG stress test for the analysis and the clinical characterization of QRS and T wave alternans

A particular database of 106 ECG records during stress testing was considered. The signal quality analysis performed in this study has permitted to obtain reliable and noise-tolerant measurements of TWA and QRSA indices. The different diagnostic groups were used for the evaluation of the clinical significance of the alternans. Men have significantly higher values of QRSA than women. Smokers have significantly higher TWA values as compared with non-smokers. Significant negative correlation was obtained between age and both TWA and QRSA. Correlations between TWA and QRSA and the double product of arterial hypertension and the maximal heart rate during the stress test were statistically significant, positive and relatively strong.