Kristen Sparrow • August 15, 2011
Here is my abstract I’m submitting for an Acupuncture Research Conference in the fall. I hope they accept it. If so, I’ll have a poster presentation, the lowest rung of a research presentation, but they’re fun to do. Wish me luck! (Other research, on same topic of course, here.)
Heart Rate Variability Analysis in the Acupuncture Clinic: Correlation with Clinical Outcomes
Kristen Sparrow, MD
San Francisco, California
Background: Heart Rate Variability (HRV) analysis is a non-invasive method of assessing autonomic tone and has been studied in conjunction with acupuncture in a number of contexts. Poor health outcomes such as impaired immunity, lowered pain thresholds, mood disorders, and even accelerated aging accompany chronic stress. Acupuncture has been shown to lower sympathetic tone and enhance vagal activity, i.e decrease the stress reponse.
In contrast to the research setting, there are time and efficiency constraints in the private acupuncture practice.In addition there can be monitoring artifacts which make frequency and time domain HRV analysis impractical and unreliable.The author hypothesizes that analysis using nonlinear analysis in addition to the aforementioned analysis methods will give a more sensitive and dependable evaluation of the patients’ autonomic state and show a more consistent correlation with clinical outcomes.
1. Assess the feasibility of evaluating HRV across time, frequency and nonlinear domains in the acupuncture clinic setting.
2. To compare intra-treatment HRV response in patients who have positive treatment outcomes to those who do not.
Design, Setting, and Patients: Case study of 20 patients presenting to a private acupuncture clinic, representing 80 treatment sessions.
Intervention: All patients received body acupuncture prescribed by the tenets of Traditional Chinese Medicine. HRV data was collected after needle placement for 20 minutes using J and J Engineering I 330 2 Biofeedback Device. . HRV data were analyzed after each treatment.
Main Outcome Measure: Patients were assessed by symptom resolution. Their HRV data were compared for the time frames “a” (60 sec to 360 sec) and “b” (360 sec to 660 sec) using Kubios shareware for the following:
1. Time series: pnn50 %
2. Frequency Domain: FFT (LFR/HFR) ratios and HFR%
3. Nonlinear results: Poincaré Plots (SD1/SD2) and Sample entropy
Patients who responded to their acupuncture treatment tended to exhibit a decrease in LFR/HFR in the segment “a,” compared to “b” by at least 30% and/or an increase from “a” to “b” in the nonlinear measurement SD1/SD2 by at least 20%.
Non-responders, or patients who were aggravated by a particular treatment tended to show no change or an increase in their LFR/HFR from “a” to “b” and a decrease in their SD1/SD2 from “a” to “b.”
Conclusions: In this study the correlation between increased HRV suggesting vagal enhancement during acupuncture treatment and positive response to acupuncture was supported. Use of nonlinear analysis in addition to frequency domain measures added to the sensitivity of HRV outcome measures.