Arterial compliance is an important cardiovascular parameter characterizing mechanical and structural properties of arteries and significantly influencing ventricular-arterial coupling. Decreased arterial compliance is associated with several physiological states and pathological processes. Furthermore, arterial compliance is influenced by other cardiovascular parameters even at short time scales. Today, there are numerous noninvasive methods of estimation arterial compliance in vivo introducing some level of confusion about selection of the best method for particular application and measurement setting. In this review, the most common noninvasive methods of arterial compliance estimation are summarized, discussed and categorized. Finally, interpretation of estimated arterial compliance in the context of other possible confounders is discussed.
Sustained orthostasis elicits the elevation of arterial blood pressure (BP) via sympathetic activation in conscious Wistar rats for at least 2 hours. We tested the hypothesis whether vestibular apparatus plays a role in BP and heart rate (HR) control in response to prolonged gravitational stress. BP and HR responses to 45º head-up for either 2 or 24 hours were monitored by telemetry. Vestibular lesions (VL) were performed by a modified microsurgical-chemical technique. Horizontal BP and HR were not influenced by VL preceding 2-hour tilt. VL abolished the sustained 2-hour BP response to head-up tilt (8.3±0.9 mm Hg relative to horizontal values) while suppressed HR transiently only. VL eliminated diurnal BP fluctuations and decreased HR in horizontal position for 24 hours. Head-up tilt for 24 hours increased BP and HR progressively in intact animals, raising their daily average value by 5.6±0.7 mm Hg and 22.2±6 BPM, respectively. VL resulted in an initial BP rise followed by progressive BP reduction in response to long-term head-up tilt (4±2.2 mm Hg) without eliminating the tachycardia (34.4±5.4 BPM). Thus, blockade of labyrinthine inputs attenuates the BP responses elicited by both intermediate and long-term gravitational stress of orthostatic type. However, other sensory inputs derived from non-vestibular cues (e.g. proprioceptive, visual, visceral, cutaneous etc.) seem to be effective enough to maintain BP normal., G. Raffai ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy