Multifractal characterization of the autonomous nervous system during prolonged coronary artery occlusion.

We assess the autonomic nervous system response during prolonged percutaneous transluminal coronary angioplasty (PTCA) by heart rate variability analysis using multifractal indices. These indices are also used to evaluate the effects of the PTCA at different arteries. The indices augmented significantly during transient ischemia and reperfusion periods indicating an increase of multifractal degree and a decrease of the long-range dependence on heartbeat fluctuations. This indicates that significant multifractal complex reactions of autonomic control of the heart rate occurred during coronary artery occlusions. Key words: multifractal analysis, heartbeat fluctuations, myocardial ischemia, coronary artery occlusion.