Modified ehlers' index for improved detection of heart rate asymmetry in poincaré plot

Abstract

Heart rate asymmetry (HRA) is a quantifiable and visible phenomena in Poincaré plot which is defined with respect to line of identity (RR(i)=RR(i+1)). In general, third moment measure (skewness) is most appropriate for quantifying asymmetry of any time series signal. Existing Elhers' index (EI) is the third moment measure but it is defined based on the actual time series signal. The aim of this study is to redefine EI as EIR in view of stated HRA definition. The new index calculated as a third moment along the minor axis of the plot from the derived signal along this axis. To show the benefit of EIR over EI, we have calculated both index values of 54 Normal Sinus Rhythm (NSR) and 272 Arrhyth..