Table 10.

Hemodynamic responses to autonomic challenges and arterial stiffness parameters

Author (s)	Years	Parameters Involved		Experiment Protocol		Association between hemodynamic responses and arterial stiffness parameter	Other findings
		Test	Arterial stiffness	Test	Arterial stiffness
Tsai et al. [37]	2003	Mental stress test (SCWT)	AIx (corrected for heart rate at 75 bpm) TAC	Continuous BP and ECG measurements in a seated position, comprising 1. 6 min resting period (baseline) 2. 6 min mental stress test (SCWT) 3. 6 min recovery period	Three pairs of cardiac impedance (SV and TPR) and AIx (augmentation pressure/PP × 100%) measurements were taken and averaged during each of the three testing phases TAC (SV/PP)	No specific analysis on association between changes in hemodynamic measurements and AIx and TAC was reported In both normotensive and hypertensive groups, A concomitant increase in SBP, DBP, MAP, PP, HR and CO, with a decrease in TAC but not on AIx	Higher SBP, DBP, MAP, PP, HR, TPR, and adjusted AIx, but lower compliance in mildly hypertensive patients as compared to normotensive subjects
Tikkakoski et al. [46]	2013	HUT	Aortic pulse pressure, aortic reflection time and AIx (corrected for heart rate at 75 bpm) PWV	Continuous measurements of hemodynamic measurements for three consecutive 5 min periods: i. resting supine on the tilt table ii. HUT to 60  iii. tilt table was returned to the horizontal position The changes in response to HUT were calculated as differences in the mean values between the last three supine minutes preceding the head up tilt and the last 3 min during the head up tilt (when the signal was most stable)	Aortic pulse pressure, aortic reflection time and AIx were determined from the derived continuous aortic blood pressure waveform PWV was derived from the body electrical impedance changes obtained using the whole-body impedance cardiography device	No specific analysis on association between changes in hemodynamic measurements and aortic stiffness parameters was reported	In hypertensive patients with significantly higher supine PWV and SVRI, aortic SBP, and aortic PP decreased less, heart rate increased less, while aortic DBP and SVRI increased more during HUT, compared to normotensive individuals AIx was reduced during HUT in spite of a parallel increase in SVR but were not statistically significantly different between two groups after adjusted analysis
Koletsos et al. [50]	2019	Handgrip test	cf-PWV AIx (corrected for heart rate at 75 bpm)	Continuous measurements of BP and HR during (i) baseline in a seated position; (ii) handgrip test: three maximal isometric handgrip contractions with the dominant hand, with a 60 s rest between each measurement (maximal voluntary contraction, MVC = the highest of the three readings); (iii) 3 min submaximal handgrip exercise test (at 30% of MVC); and (iv) 3 min recovery SBP and DBP, and HR during baseline, handgrip exercise (averaged over the 3 min, and per minute assessments, that is, first, second, and third minute of exercise), and recovery were assessed. TPR was calculated and averaged per testing period	cf-PWV in supine position AIx (corrected for heart rate at 75 bpm) in supine position	BP rise during the first minute of isometric exercise was positively associated with resting PWV, while TPR response during exercise was positivity correlated with central/aortic SBP and DBP, AIx and PWV	Central/aortic BP, PWV and AIx were significantly higher in true hypertensive patients than normotensive individuals During exercise, individuals with true hypertensive exhibited a greater SBP/DBP response (increase) than normotensive individuals. HR did not differ significantly among groups in the respective testing periods No statistically significant difference in TPR among groups at baseline. During exercise, the true hypertensive patients showed significantly increased TPR

AIx augmentation index, cf-PWV PWV between carotid and femoral arteries, CO cardiac output, DBP diastolic blood pressure, HR heart rate, HUT head-up tilt, IMT intima–media thickness, LF spectral power at low-frequency band, MAP mean arterial pressure, PP pulse pressure, PWV pulse wave velocity, RRI RR-intervals, SBP systolic blood pressure, SCWT Stroop Color and Word Test, SV stroke volume, SVR systemic venous resistance, SVRI systemic venous resistance index, TAC total arterial compliance (SV/PP), TPR total peripheral resistance