Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Involvement of sympathetic nerve activity in skin blood flow oscillations in humans
AU - Söderström , Torbjörn
AU - Stefanovska, Aneta
AU - Veber, Mitja
AU - Svensson, Henry
PY - 2003/5
Y1 - 2003/5
N2 - We have used the wavelet transform to evaluate the time-frequency content of laser-Doppler flowmetry (LDF) signals measured simultaneously on the surfaces of free microvascular flaps deprived of sympathetic nerve activity (SNA), and on adjacent intact skin, in humans. It was thereby possible to determine the frequency interval within which SNA manifests itself in peripheral blood flow oscillations. The frequency interval from 0.0095 to 2 Hz was examined and was divided into five subintervals: I, similar to0.01 Hz; II, similar to0.04 Hz; III, similar to0.1 Hz; IV, similar to0.3 Hz; and V, similar to1 Hz. The average value of the LDF signal in the time domain as well as the mean amplitude and total power in the interval from 0.0095 to 2 Hz and amplitude and power within each of the five subintervals were significantly lower for signals measured on the free flap (P <0.002). The normalized spectral amplitude and power in the free flap were significantly lower in only two intervals: I, from 0.0095 to 0.021 Hz; and II, from 0.021 to 0.052 Hz (P <0.05); thus indicating that SNA is manifested in at least one of these frequency intervals. Because interval I has recently been shown to be the result of vascular endothelial activity, we conclude that we have identified SNA as influencing blood flow oscillations in normal tissues with repetition times of 20-50 s or frequencies of 0.02-0.05 Hz.
AB - We have used the wavelet transform to evaluate the time-frequency content of laser-Doppler flowmetry (LDF) signals measured simultaneously on the surfaces of free microvascular flaps deprived of sympathetic nerve activity (SNA), and on adjacent intact skin, in humans. It was thereby possible to determine the frequency interval within which SNA manifests itself in peripheral blood flow oscillations. The frequency interval from 0.0095 to 2 Hz was examined and was divided into five subintervals: I, similar to0.01 Hz; II, similar to0.04 Hz; III, similar to0.1 Hz; IV, similar to0.3 Hz; and V, similar to1 Hz. The average value of the LDF signal in the time domain as well as the mean amplitude and total power in the interval from 0.0095 to 2 Hz and amplitude and power within each of the five subintervals were significantly lower for signals measured on the free flap (P <0.002). The normalized spectral amplitude and power in the free flap were significantly lower in only two intervals: I, from 0.0095 to 0.021 Hz; and II, from 0.021 to 0.052 Hz (P <0.05); thus indicating that SNA is manifested in at least one of these frequency intervals. Because interval I has recently been shown to be the result of vascular endothelial activity, we conclude that we have identified SNA as influencing blood flow oscillations in normal tissues with repetition times of 20-50 s or frequencies of 0.02-0.05 Hz.
KW - SPECTRUM ANALYSIS
KW - FREQUENCY
KW - time-frequency analysis
KW - WAVES
KW - blood flow variability
KW - CONSCIOUS RATS
KW - wavelet transform
KW - HEART-RATE
KW - POWER SPECTRUM
KW - autoregulation
KW - microvascular free flaps
KW - PRESSURE
KW - NEURONS
KW - SMOOTH-MUSCLE
U2 - 10.1152/ajpheart.00826.2000
DO - 10.1152/ajpheart.00826.2000
M3 - Journal article
VL - 284
SP - H1638-H1646
JO - Anerican Journal of Physiology - Heart and Circulatory Physiology
JF - Anerican Journal of Physiology - Heart and Circulatory Physiology
SN - 0363-6135
IS - 5
ER -