The relationship between heart rate and blood pressure reactivity in the laboratory and in the field:: Evidence using continuous measures of blood pressure, heart rate and physical activity

The relationship between cardiovascular reactivity in the laboratory and in everyday life has been under discussion for many years. Manuck and Krantz (1984) and light (1987) proposed three models of how laboratory reactivity could relate to real life reactions (recurrent activation, prevailing state and combined model). The aim of the present study was to test the relationship of cardiovascular reactivity in the laboratory and in the field using continuous measures of blood pressure and heart rate as well as physical activity and posture. Seventeen high and low laboratory rate pressure product (RPP) reactors were selected from a sample of 50. Continuous Finger blood pressure and heart rate (HR) were measured noninvasively with PORTAPRES for 22 hours in everyday life together with continuous measures of thigh EMG, arm movement and posture. Adrenaline, noradrenaline, cortisol, and dopamine urinary excretion Fates were determined for the same period. As predicted, high laboratory reactors showed higher daytime variability of their RPP after eliminating the effects of serial dependency and they also showed larger responses to stressful situations in everyday life. Similar, but less pronounced effects were seen for HR. High reactors also had higher daytime diastolic blood pressure (DBP) levels. In systolic blood pressure no group differences were seen. High reactors also showed higher urinary adrenaline and noradrenaline excretion rates during the day. In this study, different cardiovascular variables follow different models for the relationship between laboratory and field reactivity. For RPP and HR the "recurrent activation model" is supported. DBP may follow the "prevailing state model." Endocrine sympathetic mechanisms appear to be involved in individual cardiovascular reactivity differences.