Dynamics of cardiac system through unstable periodic orbits

For the first time unstable periodic orbits (UPO´s) are extracted from experimental human ECG signals for the quantitative classification of normal and abnormal cases. The normal cardiac system is characterized by three or four UPO´s whereas pathological conditions such as premature ventricular contraction, ventricular fibrillation, and atrioventricular block shows different trends in the number and distribution of the UPO´s