Measurement of QT interval prolongation: A comparative evaluation of six algorithms using simulated electrocardiograms

While measurement of QT prolongation in electrocardiogram (ECG) is important to clinical applications, but it is difficult to quantitatively evaluate the performance of QT measurement algorithms using clinical ECGs because the true values of the QT changes are usually unknown. In this paper, we report a comparative study to evaluate the performance of the six algorithms for QT interval prolongation measurement with computer-simulated ECGs based on a whole-heart model. Artificial zero-mean Gaussian noise with variable signal-to-noise ratios (SNR) was added to the simulated ECGs for quantitative evaluation of these algorithms with variations thresholds. The study showed that, the measurement accuracies of these six methods augment with the increase of the SNR of simulation data, while the variations of threshold of these methods have little influence on the measurement accuracy of QT interval variation. Through evaluating the QT interval prolongation values measured from the same simulated ECGs contaminated with noises, the best performance was obtained from the continuous wavelet transform based method with the mean error less than 1 ms even when the SNR is as low as 0 dB. Our study suggests that the continuous wavelet transform based method may outperform the traditional methods in estimating QT interval prolongation for ECGs with strong noise as evaluated with artificial ECGs.