Radial Artery Hemodynamic Changes Related to Acupuncture

Background: Assessment of the radial pulse by palpation (pulse diagnosis) is an important diagnostic technique in Traditional Chinese Medicine (TCM), but the changes of blood flow volume in the radial artery during and after acupuncture are unknown. Objective: The aim of this study was to explore the changes of radial artery blood flow volume during and after acupuncture in healthy subjects. Design: This study was conducted as a pilot study utilizing a one-group intervention design. Setting: The study was conducted at a TCM outpatient clinic of Tohoku University Hospital. Participants: Twenty-six healthy volunteers participated in the study. Intervention: Acupuncture was performed at LR-3 bilaterally with manual rotation of the needles. Outcome Measures: Blood pressure was measured at rest and 180 seconds after acupuncture. Radial artery hemodynamics were monitored continuously with a high-resolution ultrasound echo-tracking system. The vessel diameter and blood flow volume of the right radial artery and heart rate were measured at rest, before acupuncture, during acupuncture, and 30, 60, and 180 seconds after acupuncture. Results: The systolic and diastolic diameter of the radial artery did not significantly change. Radial artery blood flow volume decreased significantly during acupuncture (mean ± SD, 0.16 ± 0.11 mL/sec per m²; P < .01) compared with baseline (0.43 ± 0.27 mL/sec per m²), but was increased at 180 seconds after acupuncture (0.54 ± 0.28 mL/sec per m²; P < .01). Conclusions: The present study showed that radial artery blood flow volume decreased immediately during acupuncture at the LR-3 acupoint, but was increased at 180 seconds after acupuncture.