Effect of Mental Stress on R Wave Amplitude of the Electrocardiogram in Young Healthy Male Subjects

Abstract

The electrocardiographic effects of mental arithmetic stress were studied in 19 young, healthy male subjects. Blood pressure was measured by the cuff method before and during mental stress and electrocardiogram (V5) was monitored and recorded continuously throughout the study using a computerized ECG monitoring system. Heart rate increased from 65.8±7.0 (mean+standard deviation) to 76.7±9.9 beats/min (p<0.001). Systolic blood pressure rose from 122.7±9.6 to 129.1±11.7 mmHg (p<0.05), diastolic blood pressure from 76.2±8.8 to 83.0±11.0 mmHg (p<0.001), and mean blood pressure from 91.7±7.9 to 98.5±10.1 mmHg (p<0.001). These changes were all statistically significant, R wave amplitude decreased significantly from 18.6±6.9 to 17.0±6.5 mm for the group (p<0.001). No changes in the ST segment were observed; ST depression decreased from 0.56±0.47 to 0.54± 0.43 mm (N.S.) and ST slope from 0.87±0.59 to 0.77±0.63 mm/sec (N.S.). Thus it is apparent that mental stress reduced R wave amplitude without causing ST segment changes in young, healthy subjects. The mechanism and clinical implications are discussed. © 1983, International Heart Journal Association. All rights reserved.