Complexity Assessment of ECG RR Interval

Abstract

Human organism adaptation to physical load peculiarities and opportunities is an actual task of physiology, sports and clinical medicine. The solution of this task is tight-knit to human functional state evaluation. During bicycle ergometry work we can evaluate the functionality of the human organism. The main task of this work was to find the complexity measure for ECG RR interval, which could integrally and simple evaluate organism reaction to physical load. There were used the standard stress test method of provocative incremental bicycle ergometry work. For evaluation of cardiovascular system reactions the ECG analysis system “Kaunas-Load”, developed at the Institute of Cardiology was used. The investigated contingent consisted of 15 asymptomatic women (20-45 years old), participating in aerobics exercise program. We used RR intervals (ms) during every cardio-cycle. We divided data sequences to the same size intervals and calculated averages and variances (for each investigative individually). We hypothesized that the algebraic form of the dependence variance(average) is the power function. All our data satisfied this hypothesis (p<0, 05). The relation between averages and variances is called allometric. We used the logarithmic function for the lining the dependence between averages and variances. The slope of logarithmic dependence we called the allometric complexity measure. According to B J West, we hypothesized, that if the slope is negative, the complexity of the process is low and organism reaction to physical load is inadequate, if positive – the complexity is high. The higher value of complexity means better organism adaptation to physical load. For all tested women RR interval allometric complexity was positive (p<0, 05). We showed that RR interval allometric complexity for young women (20-30 years old, 8 women) is significant higher. It means, that young women organism adaptation to physical load is better and all organism systems interac.