Postural influences on the mechanical and neural components of the cardiovagal baroreflex

摘要: Aim The ability to maintain arterial blood pressure when faced with a postural challenge has implications for the occurrence of syncope and falls. It been suggested that posture-induced declines in mechanical component baroreflex response drive reductions cardiovagal sensitivity associated stress. However, these conclusions are largely based upon spontaneous methods assessment, accuracy which questioned. Therefore, aim was engage partially open-loop approach explore influence posture on neural components baroreflex. Methods In nine healthy participants, we measured continuous pressure, heart rate, RR interval carotid artery diameter during supine standing postures. The modified Oxford method used quantify sensitivity. Results In falling pressures, similar between postures (P = 0.798). In rising there an attenuated (P = 0.042) (mean ± SE) position (−0.70 ± 0.11 beats min−1 mmHg−1) compared (−0.83 ± 0.06 mmHg−1). This explained by diminished (P = 0.016) whilst (−30.17 ± 4.16 mm−1) (−38.23 ± 3.31 mm−1). These effects were consistent determined using interval. Conclusion Cardiovagal pressures is reduced young individuals Our data suggest unaffected standing, reduction driven component.