Evaluation of T wave alternans detectors based on a simulation study

A simulation study of T wave alternans (TWA) is proposed in order to evaluate the performance of typically used TWA detectors, as well as to quantify the performance characteristics in terms of sensitivity, positive predictivity and beat-to-beat amplitude estimation accuracy. ECG signals are simulated repeating a single beat, and adding mixed noise from 4 different noise sources at different levels. TWA episodes with different amplitudes and waveforms were added to the signals. We can conclude from this study that the correlation-based detector obtained much lower detection rates than the other detectors, especially in sensitivity for low amplitude TWA. The amplitude accuracy in the detected episodes was also found to be the worst with correlation-based detector. The other detectors have shown a similar behavior. However, the complex demodulation detector needs a much higher computational complexity. In general, alternans are detected with rates near 100% for SNR greater than 10 dB for physiological noise sources.