Detection of T-Wave Alternans in ECGs by Wavelet Analysis

T wave alternans (TWA) is an acute and serious problem associated with the heart and mostly they are reflected in Electrocardiogram (ECG). It is identified as an alteration of the amplitude and morphology of the T wave that occurs in every other beat indicating electrical instability in acute ischemia, where it may precede ventricular tachyarrhythmia. The analysis of TWA is introduced recently as a new diagnostic tool for identification of patients with an increased risk of ventricular tachyarrhythmia or sudden cardiac death. ECGs recorded by sophisticated equipment with specific software can only diagnose TWA. The hard and software are exorbitantly costlier and therefore not available everywhere. In the present study, the TWA is brought out very well from the amplitude of continuous Wavelet transform (CWT) which is not only cheap and simple but also highly reliable and may be considered as an alternate tool for such investigations. This study is also substantiated by the exclusively proposed new mother wavelet namely ECG wavelet. The results are presented highlighting the salient features.