CARDIOVASCULAR-RESPONSE TO MENTAL STRESS IN OFFSPRING OF HYPERTENSIVEPARENTS - THE DUTCH HYPERTENSION AND OFFSPRING STUDY

Objective: To compare blood pressure-regulating mechanisms during ment al stress in two groups of offspring with contrasting risk for hyperte nsion. Design: Cardiovascular reactivity to two different types of men tal stressors was studied in adolescents and young adults with two hyp ertensive or two normotensive parents. The two tasks used were intende d to evoke either a predominantly adrenergic cardiac response (a memor y search task) or a predominantly vascular response (a reaction-time t ask with visual search and tone avoidance) Methods: Blood pressure and heart rate were recorded at rest and during stress. To study adaptati ons of the cardiovascular system to mental stress, cardiac output, tot al peripheral resistance and indices of vagal and sympathetic influenc es on the heart were measured. Results: The reactivity of systolic blo od pressure (SEP) to the memory search task was significantly higher i n offspring of hypertensive parents, which resulted in a longer recove ry after the task. In contrast, during the reaction-time task, offspri ng of hypertensive parents had a significantly enhanced reactivity of peripheral resistance, but no differences in heart rate or blood press ure response were observed. No differences between the two groups were found in sympathetic or vagal activity during either task measured by the ratio of pre-ejection time and left ventricular ejection time, an d respiratory sinus arrhythmia, respectively. Conclusion: Apart from a higher reactivity of SEP during the memory search task, no other indi cations supporting the presence of hyperadrenergic activation of the h eart in early primary hypertension were found. On the contrary, the re sults of the present study support the hypothesis that blood pressure responses in prehypertensive subjects are characterized by enhanced va soconstriction rather than by increased cardiac output.