Multiresolution decomposition of heart rate fluctuations during carotid surgery using wavelet transform

In this study, multiresolution representations of the heart rate fluctuations using the wavelet transform method were proposed to characterize the autonomie nervous system regulation of cardiovascular activity during carotid surgery. We show that useful information from the approximation of the heart rate fluctuations at resolutions varying from 2^j+1 to 2^j can be extracted by decomposing the heart rate fluctuations on a wavelet orthonormal basis L²(R). Results suggest that the power in all frequency bands was low during surgery and increased after declamping of the carotid artery.