Physiologic Effect of Relaxation Therapies on Autonomic Tone Early After Acute Coronary Syndromes

by Friedman, Rachel Summer

Post-MI patients are at increased risk of arrhythmic sudden death. Stress and sympathetic activation are known to influence arrhythmogenesis. While relaxation therapies improve psychological well-being in multiple medical illnesses, whether these therapies can positively influence sympathovagal balance in the post-MI population is unknown. We explored the physiologic effects of Reiki, a light-touch relaxation therapy, and music on post- acute coronary syndrome (ACS) inpatients, using heart rate variability (HRV) to assess changes in cardiac autonomic function during treatment. Forty-eight patients with ACS within the last 72 hours were randomized to received a single 20-minute session of either Reiki, classical music, or a control minimal distraction environment. All subjects underwent ambulatory ECG Holter monitoring. Emotional state was assessed by Likert scale. HRV was analyzed by spectral analysis via fast Fourier transformation during the baseline, intervention, and post-intervention periods and high-frequency power (lognormalized) compared via ANOVA with repeated measures. Adequate Holters were recorded in 12 control, 13 music, and 12 Reiki patients. High frequency (HF) component of HRV, an index of parasympathetic tone, increased significantly during Reiki (0.58±0.16) but not during music (-0.1±0.16) or control (0.06±0.16). RR interval increased significantly with Reiki and control, but not with music. Reiki significantly reduced reported anxiety and increased sense of relaxation compared to control (p=0.04), whereas music did not. In conclusion, post-MI recipients of light-touch from nurses trained in Reiki experienced increased vagal activity and decreased anxiety. Whether longer-term use of this therapy can improve outcomes requires further study.