Cardiac Coherence and the Effectiveness of Cardiovascular Biofeedback in the Nursing Team: A Randomized Clinical Trial

Abstract

Introduction: Through guided and conscious deep breathing, cardiovascular biofeedback, an innovative technological tool that enables improved cardiac coherence and activation of the parasympathetic nervous system, which are vital for recovering and maintaining homeostasis and psycho-emotional health. Objective: To verify the effect of cardiovascular biofeedback on heart rate variability parameters in nursing professionals. Materials and Methods: This is a randomized clinical trial conducted in two groups — biofeedback and placebo — with 115 nursing professionals working in clinical and surgical inpatient units at a university hospital, who presented an overall stress level higher than 1, according to the Stress Symptom Scale. The groups participated in nine appointments over three weeks. The outcome was assessed by rMSSD parameters and cardiac coherence at the end of each appointment, which were measured using EmWave Pro Plus®, which uses photoplethysmography to quantify physiological data related to the heartbeat. The analysis was performed using generalized estimation equations, considering α = 5 %. Results: There was a significant time-group interaction in cardiac coherence parameters; the intervention group presented an increase in the mean cardiac coherence parameters at all measurement times, when compared to the control group (p < 0.001; r > 0.98). There was no significant time-group interaction in the rMSSD parameters at any of the measurement times (p = 0.432). As a mind-body therapy, cardiovascular biofeedback proved to be useful and promising. By promoting parasympathetic activation and relaxation, it is possible to prevent the deleterious effects associated with occupational stressors. Conclusion: The intervention with cardiovascular biofeedback proved to be superior to placebo in improving cardiac coherence, resulting in the recovery of the body’s homeostasis.