Effects of acupuncture on the harmonic components of the radial arterial blood-pressure waveform in stroke patients

Abstract

MOTIVATION: Stroke induces abnormal microcirculatory blood flow perfusion resistance in cerebral vascular beds, which may in turn alter the arterial pulse transmission. This study aimed to determine if the frequency-domain harmonic index for the blood-pressure waveform is useful in monitoring the microcirculatory blood flow perfusion response in cerebral vascular beds of stroke patients following acupuncture stimulation.

METHODS: Bilateral radial arterial blood-pressure waveform and laser-Doppler flowmetry signals were obtained noninvasively before and after acupuncture in 17 stroke patients. The amplitude proportion (C_n) for all the acquired pulses and the coefficient of variance (CV_n) for harmonics 1–10 were calculated to evaluate the blood-pressure harmonic variability.

RESULTS: The laser-Doppler flowmetry parameters showed that the cerebral microvascular blood flow supply could be improved following acupuncture. For the blood pressure waveform harmonic index, there were significant increases in C₅ and C₆ and decreases in CV₅ and CV₇ on the stroke-affected side, but no significant changes on the contralateral side.

CONCLUSION: C_n values might reflect changes in arterial pulse transmission, and the blood-pressure-harmonic-variability response might be partly attributable to cardiovascular regulatory activities caused by acupuncture-induced changes in the cerebral microvascular blood flow perfusion. The present findings of blood pressure waveform harmonic analysis may be useful to the development of a noninvasive and real-time technique for evaluating treatment efficacy in stroke patients.