Analysis of skin-temperature variability compared to variability of blood pressure and heart rate

High resolution skin-temperature measurement performed in normal human subjects and in patients with coronary artery disease revealed low-amplitude temperature oscillations (40×10^-3°C) designated as `Temperature Variability´ (TV). Spectral analysis of the filtered signal showed that most of the energy was in the range 0.015-0.04 Hz. Power spectra of temperature variability and pulse pressure amplitude were compared. Both of the signals exhibited similar peak frequency and similar stress-related response. Stress-related changes of TV power spectrum were similar to-changes of power in the spectrum of heart rate variability in the same frequency range. The TV signal showed greater sensitivity to stress than mean temperature. The TV phenomenon was attributed to vasomotor activity primarily mediated by sympathetic tone. In patients with coronary artery disease TV magnitude during baseline and stress was significantly lower than in normal subjects