RESEARCH Integrative Cardiovascular Physiology and Pathophysiology Inﬂuence of sympathetic nerve activity on aortic hemodynamics and pulse wave velocity in women

of sympathetic nerve activity on aortic hemodynamics and pulse wave velocity in women. Am (aortic) blood pressure, arterial stiffness, and sympathetic nerve activity increase with age in women. However, it is unknown if the age-related increase in sympathetic activity inﬂuences aortic hemodynamics and carotid-femoral pulse wave velocity (cfPWV), an index of central aortic stiffness. The goal of this study was to determine if aortic hemodynamics and cfPWV are directly inﬂuenced by sympathetic nerve activity by measuring aortic hemodynamics, cfPWV, and muscle sympathetic nerve activity (MSNA) in women before and during autonomic ganglionic blockade with trimethaphan camsylate. We studied 12 young premenopausal (23 (cid:2) 4 yr) and 12 older postmenopausal (57 (cid:2) 3 yr) women. These women did not differ in body mass index or mean arterial pressure ( P (cid:3) 0.05 for both). At baseline, postmenopausal women had higher aortic pulse pressure, augmented pressure, augmentation index adjusted for a heart rate of 75 beats/min, wasted left ventricular pressure energy, and cfPWV than young women ( P (cid:4) 0.05). During ganglionic blockade, postmenopausal women had a greater decrease in these variables in comparison to young women ( P (cid:4) 0.05). Additionally, baseline MSNA was negatively correlated with the reductions in aortic pulse pressure, augmented pressure, and wasted left ventricular pressure energy during ganglionic blockade in postmenopausal women ( P (cid:4) 0.05) but not young women. Baseline MSNA was not correlated with the changes in augmentation index adjusted for a heart rate of 75 beats/min or cfPWV in either group ( P (cid:3) 0.05 for all). Our results suggest that some aortic hemodynamic parameters are inﬂuenced by sympathetic activity to a greater extent in older postmenopausal women than in young premenopausal women. NEW & NOTEWORTHY Autonomic ganglionic blockade results in signiﬁcant decreases in multiple aortic pulse wave characteristics (e.g., augmented pressure) and central pulse wave velocity in older postmenopausal women but not in young premenopausal women. Certain aortic pulse wave parameters are negatively inﬂuenced by sympathetic activity to a greater extent in older postmenopausal women. San Jose, CA). Two-way repeated-measures ANOVA was utilized to determine if any signiﬁcant group (cid:7) condition interactions occurred for continuous variables (group: young vs. postmenopausal; condition: baseline vs. trimethaphan). Within-group comparisons between time points and between-group comparisons were completed using the Tukey’s post hoc test for multiple comparisons. An analysis of covariance (ANCOVA; IBM SPSS Statistics 22.00; IBM, Armonk, NY) was utilized to further examine the relationship between the decrease in peripheral blood pressure and the magnitude of change in cfPWV during trimethaphan infusion. Pearson correlation coefﬁcients ( r ) were calculated to assess the relationships among MSNA, indexes of PWA, and cfPWV. A calculated P (cid:4) 0.05 was considered signif-icant.