P9.09 Large Artery Function and Ventricular Arterial Coupling During Prolonged Bed Rest

• Published in: Artery research Vol. 3; no. 4; p. 169
• Main Authors: Santini, F., Morizzo, C., Malshi, E., Kozakova, M., Salvi, P., Pedri, S., Pagani, M., Palombo, C.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.12.2009; Springer Nature B.V; BMC
• Subjects: Poster Presentation Abstracts: Methodological Aspects 3; Veins & arteries
• ISSN: 1872-9312; 1876-4401; 1876-4401
• DOI: 10.1016/j.artres.2009.10.129

Background prolonged circulatory unloading associated with headdown tilt bed rest (HDTBR) is followed by cardiovascular deconditioning. Aim of the study was to investigate to what extent large artery function and arterial-ventricular coupling (VA) are involved. Methods: ten healthy male volunteers (age 23 ±2) were studied before and after a 35-day HDTBR. Left ventricular (LV) volumes were investigated by echocardiography; carotid diameter and intima media thickness were assessed by high resolution ultrasound (Q-IMT, Esaote Europe). Contour Wave Analysis, performed by tonometer (PulsePen, DiaTecne, Milan Italy), was used to explore large artery function. Carotid-femoral pulse wave velocity (PWV) was also estimated (Complior, Alam, Paris). Results: no changes were observed for systolic and diastolic blood pressure, PWV and QIMT vs baseline, while LV volumes showed a significant reduction (p < 0.05). Arterial Elastance (Ea= end systolic pressure/stroke volume) and LV Elastance (Elv= end systolic pressure (ESP)/end systolic volume (ESV)) increased after HDTBR (for Ea: 1.08 ±0.198 vs 1.31 ±0.21, p = 0.01; for Elv 1.478±0.32vs 1.765 ±0.42, p = 0.04) with unchanged Ea/Elv (0.74 ± 0.09 vs 0.76 ± 0.1). Contour wave analysis showed no significant changes for Augmentation Index (Aix), a reduction for PPI (Pulse Pressure Index: pulse pressure/ mean arterial pressure, from 0.55 ± 0.14to0.45 ± 0.09, p < 0.05), SEVR (subendocardial variability ratio: 1.84±0.33vs1.55±0.25, p = 0.008) and LVET(left ventricular ejection time: 304.6 ± 19.8 vs 291.5 ±11.2 ms, p = 0.05), and an increase in heart rate (from 58 ± 2 to 73 ± 6, p < 0.05). Conclusions: no significant alterations in intrinsic arterial stiffness and structure were detected after HDTBR. The observed changes in large arteries function appear secondary to changes in LV performance.