Evaluation of Multiscale Entropy based HRV for Ectopic Beats

The concomitant effect of the cardiovascular regulating mechanisms known as heart rate variability (HRV) occurs over a large set of time scales. Multiscale entropy (MSE) is a promising technique for measuring the complexity based HRV of finite length time series at different time scales. Ectopic beats, originating from other than the normal site, are the artifacts that cause a serious limitation to HRV analysis. In this study, normal RR interval time series of 10 healthy subjects with 2000 RR intervals were analysed by inserting high (g=0.1), medium (g=0.4) and low level (g=08) artificial ectopic beats. Addition of artificial ectopic beats lead to reduced complexity, resulting in decreased MSE. This reduction has been found to be dependent on amount and level of ectopic beats. Therefore certain form of ectopic editing methods are required to be apply for MSE based HRV. Interpolation methods are found to be more suitable editing methods than deletion of ectopic beats. The findings of the study can be partly used as a reference for the acceptable amount of ectopic beats for the MSE based HRV.