Cardiovascular Research Laboratory, Spaulding Hospital Cambridge, 1575 Cambridge Street, Cambridge, MA, 02138, USA.
Schoen Adams Research Institute at Spaulding Rehabilitation, Boston, MA, USA.
Clin Auton Res. 2024 Dec;34(6):571-581. doi: 10.1007/s10286-024-01060-1. Epub 2024 Sep 19.
A blood pressure stabilization during late phase II of Valsalva's maneuver may be utilized to confirm sympathetic vasoconstrictor control after a spinal cord injury. This study investigated whether Valsalva response was predictive of hemodynamics during tilt or isometric handgrip.
Presence/absence of Valsalva response was compared to heart rate, mean arterial pressure, leg blood flow, and vascular resistance during head-up tilt and isometric handgrip to fatigue in 14 adults with spinal cord injury from C7 to T12 and 14 controls. Statistics were performed with two-way repeated measure analysis of variance (ANOVA), post hoc t-tests for between-group comparisons, and Mann-Whitney U tests for within-group.
In total, six participants with spinal cord injury lacked a blood pressure stabilization for Valsalva's maneuver. However, this was not related to vasoconstrictor responses during the other tests. The groups had similar heart rate and blood pressure changes during tilt, though leg blood flow decreases and vascular resistance increases tended to be smaller at 20° tilt in those with spinal cord injury (p = 0.07 and p = 0.11, respectively). Participants with spinal cord injury had lower heart rates and markedly smaller blood pressure increases during handgrip (both p < 0.05). There were no group differences in leg blood flow, but those with spinal cord injury demonstrated a blunted vascular resistance increase by the final 10% of the handgrip (p < 0.01).
Valsalva response was not consistent with hemodynamics during other stimuli, but some individuals evidence increases in sub-lesional vascular resistance to isometric handgrip comparable to controls, suggesting a sympathoexcitatory stimulus may be critical to provoke hemodynamic responses after spinal cord injury.
在瓦尔萨尔瓦动作的第二阶段后期血压稳定可以用于确认脊髓损伤后的交感血管收缩控制。本研究调查了瓦尔萨尔瓦反应是否可预测倾斜或等长握力期间的血液动力学。
在 14 名 C7 至 T12 脊髓损伤的成年人和 14 名对照者中，比较了瓦尔萨尔瓦反应的存在/不存在与心率、平均动脉压、腿部血流和血管阻力在头高位倾斜和等长握力至疲劳期间的关系。采用双向重复测量方差分析（ANOVA）进行统计学分析，组间比较采用事后 t 检验，组内比较采用 Mann-Whitney U 检验。
共有 6 名脊髓损伤患者的瓦尔萨尔瓦动作血压稳定，但这与其他测试期间的血管收缩反应无关。两组在倾斜时的心率和血压变化相似，但在 20°倾斜时，脊髓损伤患者的腿部血流减少和血管阻力增加趋势较小（分别为 p=0.07 和 p=0.11）。脊髓损伤患者的心率较低，握力时血压升高幅度明显较小（均为 p<0.05）。两组间腿部血流无差异，但脊髓损伤患者在握力的最后 10%时血管阻力增加幅度较小（p<0.01）。
瓦尔萨尔瓦反应与其他刺激期间的血液动力学不一致，但一些个体的等长握力下亚损伤血管阻力增加与对照组相当，表明脊髓损伤后引起血液动力学反应的交感神经兴奋刺激可能是关键。
