Aging reduces complexity of heart rate variability assessed by conditional entropy and symbolic analysis

Autor(es)

Takahashi, Anielle C. M. ^[1] ; Porta, Alberto ^[2] ; Melo, Ruth C. ^{[3, 1]} ; Quiterio, Robison J. ^{[4, 1]} ; da Silva, Ester ^{[1, 5]} ; Borghi-Silva, Audrey ^[1] ; Tobaldini, Eleonora ^[6] ; Montano, Nicola ^[6] ; Catai, Aparecida M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Cardiovasc Physiotherapy Lab, Physiotherapy Dept, BR-13565905 Sao Paulo - Brazil

^[2] Univ Milan, Dept Technol Hlth, Galeazzi Orthopaed Inst, Milan - Italy

^[3] Univ Sao Paulo, Sch Arts Sci & Humanities, Sao Paulo - Brazil

^[4] UNESP Univ Estadual Paulista, Sao Paulo - Brazil

^[5] Univ Metodista Piracicaba, Fac Hlth Sci, Sao Paulo - Brazil

^[6] Univ Milan, Dept Clin Sci, L Sacco Hosp, Milan - Italy

• Tipo de documento: Artigo Científico
• Fonte: Internal and Emergency Medicine; v. 7, n. 3, p. 229-235, JUN 2012.
• Citações Web of Science: 33

Resumo

Increasing age is associated with a reduction in overall heart rate variability as well as changes in complexity of physiologic dynamics. The aim of this study was to verify if the alterations in autonomic modulation of heart rate caused by the aging process could be detected by Shannon entropy (SE), conditional entropy (CE) and symbolic analysis (SA). Complexity analysis was carried out in 44 healthy subjects divided into two groups: old (n = 23, 63 +/- A 3 years) and young group (n = 21, 23 +/- A 2). It was analyzed SE, CE {[}complexity index (CI) and normalized CI (NCI)] and SA (0V, 1V, 2LV and 2ULV patterns) during short heart period series (200 cardiac beats) derived from ECG recordings during 15 min of rest in a supine position. The sequences characterized by three heart periods with no significant variations (0V), and that with two significant unlike variations (2ULV) reflect changes in sympathetic and vagal modulation, respectively. The unpaired t test (or Mann-Whitney rank sum test when appropriate) was used in the statistical analysis. In the aging process, the distributions of patterns (SE) remain similar to young subjects. However, the regularity is significantly different; the patterns are more repetitive in the old group (a decrease of CI and NCI). The amounts of pattern types are different: 0V is increased and 2LV and 2ULV are reduced in the old group. These differences indicate marked change of autonomic regulation. The CE and SA are feasible techniques to detect alteration in autonomic control of heart rate in the old group. (AU)

• Processo FAPESP: 06/52860-0 - Efeito do treinamento de forca excentrica na modulacao da frequencia cardiaca e nas respostas da eletromiografia durante contracoes isometricas.
• Beneficiário: Anielle Cristhine de Medeiros Takahashi
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 05/54838-9 - Avaliação cardiorrespiratória e da variabilidade da frequência cardíaca de pacientes submetidos à intervenção fisioterapêutica: fases I e II da reabilitação cardiovascular
• Beneficiário: Aparecida Maria Catai
• Modalidade de apoio: Auxílio à Pesquisa - Regular