Heart Rate Variability during Cold Water Immersion Test in Patients with Hand-arm Vibration Syndrome

Autonomic nervous function during cold water immersion test in patients with hard-arm vibration syndrome (HAVS) was investigated. Fourteen patients with vibration-induced white finger and 14 healthy control subjects individually age-matched to the patients volunteered for this study. The subjects immersed the left hard into cold water at 10 ℃ for 10 min and at 15 ℃ for 3 min. These tests were conducted in summer and winter. R-R interval of electrocardiography (ECG) was analyzed with a fast Fourier transformation program and component powers of heart rate variability were calculated. Ｉｎ both seasons, normalized high frequency component power (HF%), which is an index of parasympathetic nervous activity during the immersion tests involving 10 ℃ water and 15 ℃ water, was lower in the patients than that in the controls. The difference between the patient and control groups was greater in winter than in summer. The findings indicate that cardiac parasympathetic activity in HAVS patients was lower than that cardiac parasympathetic activity in HAVS patients was lower than that in controls. Ratio of low frequency component power and high frequency component power (LF/HF ratio), Whicｈ is　an index of the 15 ℃ water, was higher in the patients than that in controls in both seasons. The findings indicate the sympathetic nervous activity of HAVS patients was higher than that of controls.

hard-arm vibration syndrome

cold water immersion test

autonomic nervous activity

heart rate variation

FFT analysis