Bernaola-Galvan, PedroIvanov, Plamen C.Nunes- Amaral, Luis A.Stanley, H. E.2020-03-312020-03-312001-10-15P. Bernaola-Galvan, P.C. Ivanov, L.A.N. Amaral, H.E. Stanley. 2001. "Scale invariance in the nonstationarity of human heart rate." PHYSICAL REVIEW LETTERS, Volume 87, Issue 16, 3 pages. https://doi.org/10.1103/PhysRevLett.87.1681050031-90071079-7114https://hdl.handle.net/2144/39908We introduce a segmentation algorithm to probe temporal organization of heterogeneities in human heartbeat interval time series. We find that the lengths of segments with different local values of heart rates follow a power-law distribution. This scale-invariant structure is not a simple consequence of the long-range correlations present in the data. We also find that the differences in mean heart rates between consecutive segments display a common functional form, but with different parameters for healthy individuals and for patients with heart failure. This finding may provide information into the way heart rate variability is reduced in cardiac disease.3 pagesen-US©2001 American Physical SocietyScience & technologyPhysics, multidisciplinaryPhysicsLong-range correlationsTime- seriesDynamicsStabilityAlgorithmsAstronautsHeartHeart diseasesHeart rateHumansMonte Carlo methodQ-bioGeneral physicsPhysical sciencesArticle10.1103/PhysRevLett.87.16810593105