Complexity Study in Multi-lead Paced ECG Signals

ECG signals have their own inherent orbit as a nonlinear attractor, but for patients with pacemaker, the pacemaker electrical pulse may disturb this natural inherent process and change the natural normal sinus beat ECG attractor. ECG signals of different leads come from the same ECG attractor, they should have the same dimension, whereas it is not true in our experiment. Using nonlinear dynamics techniques such as correlation dimension (CD) can probe the nonlinear property variation of multi-lead ECG. The CDs of 2 leads every 6 second ECG segments from several recordings of MIT-BIH Arrhythmia Database are calculated, including 4 paced recordings. Results show that CDs of different leads ECG signals have significant difference although they come from the same ECG attractors. The paced ECG signals have less complicated properties than normal sinus ECG