Ambulatory blood pressure monitoring and laboratory reactivity in type A behavior and components.

Type A coronary-prone behavior has been characterized previously by cardiovascular hyperreactivity to laboratory stressors. The objectives of this study were: 1) to determine whether cardiovascular patterns under more naturalistic circumstances in the field were altered in Type A subjects, and 2) to determine whether these field patterns paralleled cardiovascular patterns to a series of stressors in the laboratory. Thirty-three healthy Type A and B men underwent 24-hr ambulatory blood pressure and heart rate monitoring during a normal day of activities. These subjects were also tested in the laboratory for blood pressure and heart rate responses to a series of stressor tasks: 1) cognitive (mental arithmetic), 2) perceptual motor (reaction time), and 3) physical (handgrip). Type A behavior and stylistic components were rated by structured interview. All studies were conducted double blindly. Type A subjects demonstrated greater cardiovascular reactivity to the laboratory cognitive stressor, but there was a mixture of differences between As and Bs in variability of ambulatory blood pressure and heart rate during different periods of the day. Yet, there were no differences in average blood pressure levels. The components of verbal competition and loudness of voice were positively associated with elevated average blood pressure and variability in the field, respectively, but not with laboratory hyperreactivity. Thus, this study confirmed laboratory-induced cardiovascular hyperreactivity in Type A behavior but, within its limitations, did not find a similarity between laboratory and field cardiovascular response patterns in these behavioral groups. The ambulatory blood pressure monitoring findings in the component groups may have prognostic significance and deserve further study.