Long-term cognitive-behavior therapy improves autonomic heart rate control in patients after cardiac surgery

Abstract

Various studies have demonstrated that effective cognitive behavior therapy (CBT) reduces stress and anxiety levels. However, little is known about the effect of CBT on autonomic responses as measured by heart rate variability (HRV) in patients after cardiac surgery. This study is a randomised controlled clinical investigation of CBT efficacy on autonomic heart rate control in patients who had undergone coronary bypass surgery or coronary bypass combined with valve procedure surgery. Objective: To examine the impact of CBT for stress management on the HRV parameters. Methods: The CBT and control groups both consisted of 36 patients. The therapy course lasted nine months (18 sessions). The final analysis was done for 15 therapy group patients and for 11 control group patients. Autonomic heart rate control was investigated by ECG registration for five minutes at rest and during active orthostatic test (AOT). Assessment of autonomic heart rate control was carried out by heart rate power spectral analysis. The parameters of HRV were investigated: the RR interval, RR interval variability (sRR), high frequency power (HF%), low frequency power (LF%), sympathetic activity index (LF/ HF), heart rate reaction to AOT (RRBms). Markedly reduced heart rate reaction to AOM was considered RRb≤0.2 s; increased LF/HF≥1.1 and decreased HFC%≤19.99%. Results: The results have shown significant changes in some HRV parameters dynamics. The number of patients with low sRR, with shortened heart rate reaction to AOT, and the mean RR interval have decreased (pb0.05). The mean of sRR and the mean of heart rate reaction to AOT have increased (pb0.05). The frequency domains of HRV didn't change. There were no changes in HRV parameter dynamics in the control group. [...]