The Effect of Increasing HRV Resonance Frequency on Reduction of Depression in post-CABG patients

Two decades of researches showed a linear relationship between heart rate variability (HRV) and emotion regulation، health and disease. HRV reduction was associated with increasing depression symptoms، CHD progress and subsequent mortality. The purpose of the study was to investigate the effect of increasing HRV resonance frequency of post-CABG patients using psychological interventions (emotion-focused and cognitive techniques) on reduction of depression. We selected 75 CABG patients who participated in cardiac rehabilitation program of Tehran Heart Center. The patients randomly assigned to 3 groups: 1) emotion-focused intervention group 2) mixed (cognitive and emotion- focused) intervention group and 3) control group (common hospital interventions). All of the groups completed DASS-21 depression subscale before and after of interventions. Their HRV resonance frequency was also recorded before and after of interventions. They received interventions for 5 week included group sessions، individual sessions، personal practice، home assignments and HRV biofeedback. The results indicated emotion-focused and mixed (cognitive and emotion-focused interventions) interventions increased HRV resonance frequency and decreased depression in post-CABG patients. The findings were significant statistically for resonance frequency (p<0/01) as well as depression (p<0/05) and the reduction of depression symptoms were also significant clinically.