Short-term heart rate variability measures in students during examinations

Area of Science:

• Cardiology
• Autonomic Nervous System Function
• Psychophysiology

Background:

• Heart rate variability (HRV) alterations are observed in various diseases, suggesting cardiac autonomic dysfunction.
• The role of anxiety-induced mental stress in these HRV changes remains unclear.
• This study investigates the impact of acute mental stress on HRV.

Purpose of the Study:

• To determine if mental stress alone can alter heart rate variability parameters.
• To compare HRV during a stressful event (university examinations) versus a relaxed state (holidays).

Main Methods:

• Short-term (5-minute) electrocardiogram recordings were obtained from 18 healthy students.
• HRV parameters, respiratory rate, and blood pressure were measured during examinations and holidays.
• Data were analyzed to compare HRV metrics between the two conditions.

Main Results:

• Mean RR interval and mean arterial pressure were significantly altered during examinations.
• Total HRV measures, including standard deviation of normal-to-normal intervals and total spectral power, were significantly reduced during examinations.
• Normalized low frequency (LF nu), high frequency (HF nu), and the LF/HF ratio showed no significant differences.

Conclusions:

• Mental stress during examinations leads to decreased mean RR interval, indicating increased heart rate and cardiac sympatho-excitation.
• Total HRV is diminished under mental stress.
• The sympathetic-to-parasympathetic balance, as indicated by LF/HF ratio, was not significantly affected by acute mental stress.