A Harmonic Analysis of Cardiac Response of Normotensive and Hypertensive Adolescents during Stress

In this paper, a statistical analysis is applied to the systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) data of 23 normotensive (NT) and 24 hypertensive (HT) adolescents who underwent a 10-minute mental stress regimen. Readings were measured at one-minute intervals. The harmonic time series analysis is based on the data of an eight-minute interval of the stress phase. The NT group established a statistically significant (p less than .05) rhythmic variation described by a sinusoidal wave about a near pre-stress mean. The HT group exhibits for the three parameters a near constant response about a significantly elevated level. The consistent existence of a rhythmic pattern for the NT subjects under mental stress, in contrast to the constant response for the HT subjects, suggests that mental stress causes a change in the "natural" rhythmic pattern of cardiac response for the HT subject alone.