Effects of stroke localization on nonlinear indexes of HRV

To evaluate the relationship between lesion's severity and nonlinear indexes of HRV, 20 first-ever stroke subjects and 10 healthy subjects were studied. All patients, divided in two groups according to presence of single or multiple medium cerebral artery lesion, underwent to a 24-hour Holter ECG recording. All RR time series were analyzed by Poincarè Plot, fractal dimension, power-law behaviour, spectral and time-domain techniques. A direct relationship between increasing lesion's severity and progressive collapsing of PPlots and FD index was observed, while lower significance were found for beta exponent, spectral and time-domain parameters. These results suggest that PPlots and FD analysis contains relevant information related to different HRV dynamics in normal and stroke subjects with different lesion's severity.