Comparison of Neurophysiological Characteristics Using Heart Rate Variability Between Patients With Korean Hwa-byung and Healthy Individuals

Objective Hwa-byung (HB) is a syndrome associated with stressful events within Korea’s social and cultural contexts. The clinical symptoms of HB may be associated with autonomic imbalance. This study investigated the neurophysiological characteristics of HB by comparing heart rate variability (HRV) between patients with HB and healthy controls (HCs).Methods This study included 67 patients with HB and 72 HCs. We used psychological assessments, including trauma, life events, anger, and affective symptoms, along with the Hwa-Byung Scale (HBS). Neurophysiological data were evaluated by measuring HRV parameters. Statistical analyses included independent t-tests, chi-square tests, and Pearson correlation analyses.Results Patients with HB showed significantly higher early trauma, and total HBS, Aggression Questionnaire-hostility, and State-Trait Anger Expression Inventory-2 (STAXI-2) state anger and anger suppression subscale scores. The HB group exhibited a higher low-frequency (LF)/ high-frequency (HF) ratio, higher LF, lower HF, lower total power, and lower very low frequency values. Within the HB group, Pearson’s correlation analyses revealed positive significant correlations of the LF/HF ratio with HBS total score, HBS symptom subscale score, and STAXI-2 anger control-in scores.Conclusion The study findings provide new insights into the neurophysiological characteristics of patients with HB compared with those of HCs, as measured by HRV. The HB group exhibited an imbalance in the autonomic nervous system. Moreover, the significant correlations between HB symptoms and the LF/HF ratio suggest that the LF/HF ratio may serve as a physiological marker of the severity of the clinical symptoms of HB.