Abstract
Introduction: Hypertension is a leading modifiable risk factor for cardiovascular disease and is commonly associated with autonomic dysfunction, characterized by increased sympathetic activity and reduced parasympathetic modulation. In addition to pharmacological treatment, non-pharmacological interventions such as aerobic exercise and breathing- based therapies have gained increasing attention for their beneficial effects on cardiovascular regulation. Digital heart rate variability (HRV) biofeedback-guided resonance breathing is an emerging intervention that combines paced breathing with real-time physiological feedback to enhance vagal activity and improve autonomic balance.
Methods: A three-arm parallel experimental study was conducted among 48 individuals with hypertension receiving antihypertensive medication. Participants were equally assigned to three groups (n=16 each). Group A received medication alone and served as the control group. Group B performed moderate-intensity aerobic exercise at 60–70% of maximum heart rate for 30 minutes per session. Group C completed the same exercise program followed by HRV biofeedback-guided resonance breathing using a chest-strap heart rate monitor integrated with a mobile biofeedback application. The intervention was delivered three times per week for eight weeks. Systolic and diastolic blood pressure were assessed as primary outcomes, while HRV parameters (RMSSD, SDNN, LF, HF, and LF/HF ratio) were evaluated to assess autonomic function.
Findings: Participants in the combined intervention group demonstrated greater reductions in systolic blood pressure and more favorable changes in HRV parameters than those in the exercise-only and control groups. One-way ANOVA demonstrated a statistically significant between-group difference in the change in systolic blood pressure (P<0.001). In contrast, the between-group difference in diastolic blood pressure was not statistically significant (P=0.221). Significant between-group differences were also observed for the HRV parameters.
Conclusion: The combination of HRV biofeedback-guided resonance breathing and moderate-intensity aerobic exercise may be an effective complementary intervention to improve blood pressure regulation and autonomic function in individuals with hypertension.