Effect of sample rate on saECG spectrum

Signal-averaged ECG (saECG) has been used to show delayed ventricular activation and myocardial infarction, but alignment jitter acts as a low-pass filter. Jitter arises due to sampling of the signal, and due to imperfect alignment algorithms. In this study we investigated the influence of the sample rate on the saECG spectrum, i.e. if the jitter can be minimized by increasing the sample rate. High speed high resolution ECGs were recorded from 6 volunteers in a shielded room. The spectrum of both raw beats and the saECG were computed and compared, and we found that sample rate does indeed influence the intrinsic low-pass filtering of the signal caused by jitter.