title: Ecological assessment of heart rate complexity: Differences between high- and low-anxious adolescents.
abstract: Nonlinear measures can capture the complex structure of the heart beating, and recordings taken while the individual performs daily activities may help to understand the cardiac system's output in natural conditions. As healthy systems are characterized by having highly complex outputs, we hypothesized that the cardiac output from high anxious adolescents should be less complex than the output from their low anxious counterparts. In this study ECG was recorded for two hours in 50 adolescents while they performed regular school activities. Fractal dimension (FD), scaling exponents and multiscale entropy were calculated on the interbeat intervals time series. Both FD and entropy were significantly lower in the high-anxious group than the low-anxious group. These results suggest different heart-related regulation in adolescents who suffered from high anxious symptomatology.
authors.affiliation: University of the Balearic Islands, University Research Institute on Health Sciences, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Bornas
authors.affiliation: University of the Balearic Islands, University Research Institute on Health Sciences, Spain. Electronic address: ballemaria@gmail.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Balle
authors.affiliation: University of the Balearic Islands, University Research Institute on Health Sciences, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: De la Torre-Luque
authors.affiliation: University of the Balearic Islands, University Research Institute on Health Sciences, Spain.
authors.forename: Aina
authors.initials: A
authors.lastname: Fiol-Veny
authors.affiliation: University of the Balearic Islands, University Research Institute on Health Sciences, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Llabrés
mesh_terms: D000293:Adolescent; D001007:Anxiety / Q000503:physiopathology*; D015992:Body Mass Index; D002648:Child; D004562:Electrocardiography; D019277:Entropy; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D017711:Nonlinear Dynamics; D011569:Psychiatric Status Rating Scales; D057566:Self Report; D013694:Temperament
keywords: Adolescent; Anxiety; Complexity; Heart rate