Analysis of flux motion by the laser Doppler technique in the forefoot of healthy controls and patients with peripheral arterial occlusive disease was performed by establishing computerized frequency histograms. It was found that the low frequency components (1-10 cycles/min) are caused by local vasomotion. The prevalence of high frequency flux waves (15-25 cycles/min) is significantly increased in peripheral ischemia compared to normal conditions. After successful reopening of large arteries by angioplasty the prevalence decreases (p less than 0.001). Preliminary results indicate that these high frequency rhythmic fluctuations might by induced by respiration.