Changes in heart rate variability during psychological stress in cardiorespiratory failure patients

Abstract

Background: Cardiorespiratory failure (CRF) patients have autonomic alterations, in rest or in physical activity. The Heart Rate Variability (HRV) is a biomarker of the autonomic changes during external or internal events including psychophysiological stress. But, the changes in HRV associated to psychological stress have been few explored. Purpose: To observe the changes in HRV of CRF patients during psychological stress. Methods: A descriptive cross-sectional study was conducted, involving 72 CRF patients. The psychophysiological evaluation of three phases was performed: repose, arithmetic stressor and natural relaxation. The HRV was recorded through a photoplethysmography sensor. The HRV level was calculated by dividing low frequencies between high frequencies and patients were classified into three groups: high variability (HV; 0 to 0.8), medium variability (MV; 0.9 to 1.1) and low variability (LV; >1.1). Results: For the LV group, the age average was 67± 12.08 years old, 44.4% were women, whilst to the HV group was 67±13.76 years old, 13.8% were men. The LV patient’s percentage in the three phases was: 61, 65.27 and 63.88% respectively. The most part of the patients didn’t present a correct recovery, they decremented their HRV, both in LV group (85.36%) and in the HV group (57.14%). Only the 34.74% of the patients achieved a correct psychophysiological recovery. Conclusions: Most of the patients showed an autonomic dysregulation, observed like a hyperactivity associated with a low or null optimal capacity of recovery and with low levels of HRV. It is important generate a multidisciplinary treatment focused on the management of the psychological stress in these patients.