BLOOD-PRESSURE RESPONSES TO STRESS - RELATION TO LEFT-VENTRICULAR STRUCTURE AND FUNCTION

The relations of resting blood pressure, blood pressure during standar dized stressors, and workplace blood pressure to left ventricular stru cture and diastolic filling were evaluated in 133 healthy young adults (mean age = 30 +/- 7 years) without hypertension. Each subject underw ent the following: (a) measurement of basal blood pressure at the end of 15 minutes of rest; (b) measurement of blood pressure during a comp etitive reaction time task (a laboratory stressor which elicits a beta -adrenergically mediated increase in cardiac output); (c) measurement of blood pressure during a forehead cold pressor test, which results p rimarily in an increase in total peripheral resistance due to alpha-ad renergic stimulation; and (d) ambulatory blood pressure monitoring dur ing a typical workday. Left ventricular structure (indexed left ventri cular mass and relative wall thickness! and diastolic filling (peak fi lling velocity) were evaluated by echocardiography. All four measures of systolic blood pressure were significantly correlated with indexed left ventricular mass. The best predictor of indexed left ventricular mass was the systolic blood pressure during the cold pressor test (r = 0.32, p < 0.001), and this relation was significant after correcting for resting systolic blood pressure (p < 0.05). Relative wall thicknes s was most closely related to the average ambulatory workplace systoli c pressure (r = 0.23, p < 0.01), and this relation was also independen t of resting systolic blood pressure (p < 0.05). Peak filling velocity was inversely related to the systolic pressure in response to each st ressor, but the correlations with stress-induced pressures were not si gnificant after correcting for resting levels of blood pressure. These results demonstrate an association of structural characteristics of t he left ventricle with blood pressure responses to stress.