Fractal correlation property of heart rate variability in chronic obstructive pulmonary disease

• Autor(a) principal: Carvalho, Tatiana D. [UNESP]
• Data de Publicação: 2011
• Outros Autores: Pastre, Carlos Marcelo [UNESP], de Godoy, Moacir Fernandes, Fereira, Celso, Pitta, Fabio O. [UNESP], de Abreu, Luiz Carlos, Cipulo Ramos, Ercy Mara [UNESP], Valenti, Vitor E., Marques Vanderlei, Luiz Carlos [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.2147/COPD.S15099; http://hdl.handle.net/11449/7063
• topic: pulmonary disease; chronic obstructive; heart rate; nervous system; cardiology

Background: It was reported that autonomic nervous system function is altered in subjects with chronic obstructive pulmonary disease (COPD). We evaluated short-and long-term fractal exponents of heart rate variability (HRV) in COPD subjects.Patients and methods: We analyzed data from 30 volunteers, who were divided into two groups according to spirometric values: COPD (n = 15) and control (n = 15). For analysis of HRV indices, HRV was recorded beat by beat with the volunteers in the supine position for 30 minutes. We analyzed the linear indices in the time (SDNN [standard deviation of normal to normal] and RMSSD [root-mean square of differences]) and frequency domains (low frequency [LF], high frequency [HF], and LF/HF), and the short-and long-term fractal exponents were obtained by detrended fluctuation analysis. We considered P < 0.05 to be a significant difference.Results: COPD patients presented reduced levels of all linear exponents and decreased short-term fractal exponent (alpha-1: 0.899 +/- 0.18 versus 1.025 +/- 0.09, P = 0.026). There was no significant difference between COPD and control groups in alpha-2 and alpha-1/alpha-2 ratio.Conclusion: COPD subjects present reduced short-term fractal correlation properties of HRV, which indicates that this index can be used for risk stratification, assessment of systemic disease manifestations, and therapeutic procedures to monitor those patients.