Blood pressure and electrocardiographic changes elicited by the glare pressor test.

The glare and cold pressor tests with blood pressure and ECG recording were administered to 47 young, healthy men. Both stimuli increased mean systolic and diastolic blood pressure significantly. However, cold was more powerful than glare as a diastolic pressor stimulus. Heart rate and corrected QT interval increased significantly during both tests. Professional and nonprofessional drivers who drove at night showed significantly greater diastolic BP responses to the glare pressor test than did non-driver subjects. Ventricular extrasystoles (VES) were recorded exclusively during the glare pressor test in two of six professional drivers with night driving exposure. The heart rate and QT responses reflect the individual's reactivity to sensory stress, regardless of modality or glare exposure. On the other hand, the greater diastolic response and appearance of VES in night driving subgroups during glare suggest a greater sensitivity to the glare pressor test in these subjects.