In this work a simulation study of T-wave alternans is proposed in order to determine the ability of TWA detectors to quantify the performance characteristics in terms of amplitude estimation accuracy. ECG signals were simulated by repeating a single beat, and by adding four types of noise each at two different levels of power. TWA episodes with different amplitudes and waveforms were added to the signals. In simulated ECG signals sampling frequency as well as amplitude resolution were reduced. We can conclude from this study that all analysed methods of TWA detection are resistant to changes of amplitude resolution but there is strong influence of sampling frequency on the precision of TWA amplitude estimation .