Assessing Psychological Stress in Coronary Artery Disease Through Heart Rate Variability

Coronary artery disease (CAD) is intricately associated with physiological and psychological stress, which can negatively affect cardiac autonomic control. Heart rate variability (HRV), a noninvasive indicator of autonomic nervous system function, has become an important instrument for evaluating stress levels.

A cross-sectional observational study was performed on 100 patients diagnosed with coronary artery disease at a tertiary care facility during a 6-month duration. The Perceived Stress Scale (PSS-10) was utilized to evaluate standardized psychological stress. Heart rate variability (HRV) was measured using a 5-minute electrocardiogram (ECG) in a supine resting position, with subsequent analysis of both time-domain (SDNN, RMSSD) and frequency-domain (LF, HF, LF/HF ratio) parameters with Kubios HRV software. Patients were classified into low, moderate, and high stress categories according to PSS ratings, and HRV value.

Among 100 participants, 38% exhibited high stress levels, 42% demonstrated moderate stress, and 20% reported low stress scores. A notable decrease in SDNN and RMSSD values was seen in the high stress group (SDNN: 23.5 ± 7.2 ms; RMSSD: 18.3 ± 5.6 ms) relative to the low stress group (SDNN: 42.8 ± 10.4 ms; RMSSD: 34.1 ± 8.9 ms) (P < 0.001). The frequency-domain characteristics indicated a larger LF/HF ratio in the high-stress group (3.1 ± 1.2) compared to the low-stress group (1.4 ± 0.6). Pearson's correlation indicated a robust negative association between PSS scores and RMSSD (r = -0.68, P < 0.001).

HRV research reveals substantial changes in CAD patients under psychological stress, signifying diminished parasympathetic activity and autonomic dysregulation.