[Pressure variability in the cold-pressure response test].
The effect of the immersion of the hand in ice water for 5 minutes on the short-term variability of blood pressure (BP) and heart rate (HR) was evaluated in 10 normal subjects. Indirect finger BP was measured by a non-invasive device (Finapres). Analogue-to-digital conversion of the BP was used to determine systolic, diastolic BP and HR every 0.5 second. The equidistant sampling allowed a direct spectral analysis using a fast Fourier transform algorithm on 256 point time series of a stationary period. BP was increased (+28 mmHg for systolic BP and +13 mmHg for diastolic BP) and an increased overall variability of BP and HR was observed during the cold pressor test. The increased areas under the curve of the systolic, diastolic BP and HR spectra were documented with the selective analysis of the two main components of the spectra: the increase in the oscillations of BP and HR during the test predominated in the 70-140 mHz region (+30% for systolic BP, +24% for DBP and +21% for HR), corresponding to Mayer waves. The high-frequency (respiratory) component of BP and HR variability was unchanged. The significant increase in the 10 second period oscillations of BP could reflect the cold-induced sympathetic vasoconstriction.
Girard
A
A
Pharmacologie clinique, Association Claude-Bernard, CNRS URA 1482, hôpital Necker-Enfants Malades, Paris.
Weise
F
F
Laude
D
D
Elghozi
J L
JL
D000222:Adaptation, Physiological; D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D003080:Cold Temperature; D005260:Female; D006801:Humans; D008297:Male; D013564:Sympathetic Nervous System / Q000502:physiology
Variabilité tensionnelle au cours de la réponse pressive au froid.