Influence of electroacupuncture stimulation on skin temperature, skin blood flow, muscle blood volume and pupil diameter.

OBJECTIVE: To examine the effect of electroacupuncture (EA) stimulation on multiple physiological indices and to evaluate both local and systemic physiological responses induced by the stimulation. METHODS: 15 healthy male college students participated in an experimental crossover study. They received two kinds of interventions: one with EA stimulation and one without EA stimulation on different days. Two disposable acupuncture needles were inserted at two traditional acupuncture points (ST36 and ST38), located along the anterior tibialis muscle. EA stimulation was administered for 10 min. Skin temperature (ST), skin blood flow (SBF) and muscle blood volume (MBV) were recorded near the stimulation sites, while the pupil diameter (PD) was measured before, during and after the interventions. RESULTS: ST, SBF and MBV increased significantly following EA stimulation. PD of the right and left eyes decreased significantly following EA stimulation. There was a significant difference in ST responses between the groups (P=0.001). For SBF, MBV and PD, no significant differences were demonstrated between the groups. CONCLUSIONS: Our study showed that 10 min of EA stimulation increased ST, SBF and MBV, and decreased PD, compared to baseline, while no significant change was observed in the control group. This suggests that EA stimulation alters local blood flow and ST, and these responses are likely mediated via segmental spinal reflexes, supraspinal reflexes involving parasympathetic activation, and other mechanisms.

Effects of drug, biobehavioral and exercise therapies on heart rate variability in coronary artery disease: a systematic review.

BACKGROUND: Heart rate variability (HRV) is reported as a surrogate index for clinical outcome in trials of secondary prevention strategies for coronary artery disease (CAD), but a standardized guide for interpreting HRV change is not established. DESIGN: We evaluated HRV change in trials with CAD patients who received conventional medications (beta-blockers, calcium channel blockers, angiotensin converting enzyme inhibitors), biobehavioral treatment (psychotropics, biofeedback, relaxation) or exercise training. METHODS: Medline, Pubmed, Psycinfo, the Cochrane database, and Embase were searched until July 2007, without language restriction. We identified 33 randomized controlled trials. Two reviewers independently abstracted all trials using a standardized form. A hierarchy of frequency and time domain HRV indices defined outcome. RESULTS: A random-effects model yielded an overall pooled standardized mean difference (SMD) between treatment and control groups of moderate magnitude across treatment classes, based on a composite of time and frequency domain indices (SMD=0.40, P<0.0001), or only time or frequency indices (SMD=0.37 and 0.43, respectively, both P<0.0001). This change was equivalent to an increase in standard deviation of all normal-to-normal RR intervals of 9.0 ms (95% Confidence Interval, CI, 7.3, 10.7 ms) or a relative increase of 15.9% (95% CI, 13.2, 18.6%). To detect HRV change of this magnitude, a hypothetical trial would require a sample size of 660 patients for conventional medications or 1232 patients for all treatment classes. CONCLUSION: Pharmacologic, biobehavioral and exercise strategies for secondary prevention of CAD significantly increase HRV. This review provides a framework to assist efforts to evaluate the contribution of HRV change to CAD prognosis.