Influence of exam stress on the structure of the circadian heart rate

Abstract

We analyzed the circadian rhythms of some characteristics of the ECG (heart rate and the number of completed QRS) of students of an university during examinations. Paired t-test daily dynamics of average heart rate and QRS data during examinations and control, regardless of the season showed a significant increase of MESOR (p = 0.019) and a shift of acrophase during exams (p = 0.008). Spectrum of heart rate of students showed high statistical significance for 24-hour rhythm in control (p<0,001 at summer and p=0,001 at winter), during summer exam session significance for this rhythm decreased (p<0,005), during winter exam session 24-hours rhythm is not significant (p=0,07). Also during exam days appear ultradian rhythms with periods 12 h, 8 h and 2,7 h, in most of cases for student в students with good academic performance.