title: Scaling and universality in heart rate variability distributions.
abstract: We find that a universal homogeneous scaling form describes the distribution of cardiac variations for a group of healthy subjects, which is stable over a wide range of time scales.  However, a similar scaling function does not exist for a group with a common cardiopulmonary instability associated with sleep apnea. Subtle differences in the distributions for the day- and night-phase dynamics for healthy subjects are detected.
authors.affiliation: Department of Physics, Boston University, MA 02215, USA.
authors.lastname: Ivanov PCh
authors.forename: M G
authors.initials: MG
authors.lastname: Rosenblum
authors.forename: C K
authors.initials: CK
authors.lastname: Peng
authors.forename: J E
authors.initials: JE
authors.lastname: Mietus
authors.forename: S
authors.initials: S
authors.lastname: Havlin
authors.forename: H E
authors.initials: HE
authors.lastname: Stanley
authors.forename: A L
authors.initials: AL
authors.lastname: Goldberger
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D003627:Data Interpretation, Statistical; D005260:Female; D017709:Fractals; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D013997:Time Factors