Spectral characteristics of heart rate variability before and during postural tilt. Relations to aging and risk of syncope.

• DOI: 10.1161/01.cir.81.6.1803
• Publication Date: 2011-06-17T20:29:13Z
• Authors: L A Lipsitz; J Mietus; G B Moody; A L Goldberger
• Keywords: Supine position; Vasovagal Syncope; Tilt table test; Spectral Analysis

Fourier analysis of heart rate (HR) may be used to characterize overall HR variability as well low- and high-frequency components attributable sympathetic vagal influences, respectively. We analyzed spectral characteristics 12 healthy young (18-35 years) 10 old (71-94 subjects before during 60 degrees head-up tilt. Total power in the 0.01-0.40-Hz frequency range low-frequency (0.06-0.10 Hz) (0.15-0.40 spectrum were significantly lower than supine upright positions. To compare subjects, we computed regression lines relating log amplitude spectra (l/fx plots). The for steeper (mean slope, -0.78 [5%, 95% confidence limits (CL), -0.73, -0.83]) -0.67 [CL, -0.62, -0.72]), indicating not only reduced but also relatively greater attenuation subjects. This finding illustrates a novel way quantify loss autonomic influences on regulation function age. During postural tilt, was unchanged For entire group total increased Six developed vasovagal syncope enabling us examine differences these while they asymptomatic syncope.(ABSTRACT TRUNCATED AT 250 WORDS)