Heart Rate Variability and Slow-Paced Breathing in Mothers of Children with Disabilities: Autonomic Flexibility Under Chronic Caregiving Stress.

Abstract

This pilot study examined the psychological, physiological, and autonomic effects of chronic caregiving stress in mothers of children with disabilities and evaluated the acute impact of slow-paced breathing (SPB; ~0.1 Hz) on heart rate variability (HRV) and emotional responses. Fourteen caregiving mothers (M = 49.0 ± 8.6 years) and 14 age-matched controls (M = 43.9 ± 5.8 years) participated in three five-minute conditions: resting baseline, cognitive stress, and SPB. Measures included psychological distress, resilience, body composition, musculoskeletal pain, HRV, and emotional states. Caregivers showed greater psychological distress, lower resilience, and higher visceral adiposity and musculoskeletal pain than controls. Global HRV indices (SDNN, TP) were significantly reduced in caregivers, reflecting diminished integrative autonomic capacity, whereas vagally mediated measures (RMSSD, ln(HF)) remained comparable, indicating preserved basal vagal tone despite chronic stress exposure. During SPB, SDNN, TP, ln(LF), and LF/HF increased significantly, while RMSSD and ln(HF) remained stable, suggesting a resonance-driven reorganization of autonomic activity through enhanced baroreflex-vagal coupling rather than direct vagal amplification. Emotionally, both groups showed reduced anxiety and tension following SPB; however, caregivers continued to report elevated perceived stress, indicating a psychophysiological dissociation between physiological recovery and subjective experience. These findings provide preliminary evidence that SPB facilitates short-term autonomic recovery and emotional stabilization in chronically stressed caregivers. As a rapid, low-burden, and non-pharmacological intervention, SPB holds promise for enhancing autonomic coherence and stress resilience when incorporated into caregiver support programs.