Palamarchuk Iryna S, Baker Jacquie, Kimpinski Kurt
Department of Clinical Neurological Sciences, University Hospital, London Health Sciences Centre, London, Ontario, Canada; and Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.
Department of Clinical Neurological Sciences, University Hospital, London Health Sciences Centre, London, Ontario, Canada; and.
Am J Physiol Regul Integr Comp Physiol. 2016 Feb 1;310(3):R243-52. doi: 10.1152/ajpregu.00290.2015. Epub 2015 Oct 21.
The objective of this study was to assess hemodynamic responses and baroreflex sensitivity (BRS) indexes during Valsalva maneuver (VM) and head-up tilt (HUT) testing in orthostatic intolerance (OI). Patients with neurogenic orthostatic hypotension (NOH, n = 26), postural tachycardia syndrome (n = 26) and symptomatic OI (n = 14) were compared with healthy population (control, n = 107) and inappropriate sinus tachycardia (n = 7). Hemodynamic assessment included patterning and quantification with vagal and adrenergic BRS (BRSa/BRSa1). In NOH, cardiovagal systolic blood pressure (SBP) decrements in VM and HUT were correlated (r = 0.660, P < 0.001); a "V" pattern of VM indicated α-BRSa failure. Yet BRSa1 did not reveal changes vs. control (P > 0.05) or was not applicable in 60% of NOH. In symptomatic OI, compared with control, cardiovagal SBP decrements were larger (P < 0.05); higher BRSa1 contradicted higher adrenergic index (Composite Autonomic Severity Score). Overshoot in phase IV dipped below baseline or dropped ≥ 10 mmHg over 8 s in postural tachycardia syndrome ("N" pattern), but by 3 s in inappropriate sinus tachycardia ("M" pattern). Visualization of distinct VM patterns allows primary evaluation of autonomic dysfunction and differentiation of the various forms of OI. BRSa1 evaluation is compromised by pathological SBP patterns. VM patterning is a valuable nonpostural supplement to HUT capable of detecting and differentiating OI.
本研究的目的是评估体位性不耐受（OI）患者在瓦尔萨尔瓦动作（VM）和头高位倾斜（HUT）测试期间的血流动力学反应和压力反射敏感性（BRS）指标。将神经源性体位性低血压（NOH，n = 26）、姿势性心动过速综合征（n = 26）和有症状的OI（n = 14）患者与健康人群（对照组，n = 107）和不适当窦性心动过速（n = 7）患者进行比较。血流动力学评估包括通过迷走神经和肾上腺素能BRS（BRSa/BRSa1）进行模式识别和量化。在NOH患者中，VM和HUT期间的心血管迷走神经收缩压（SBP）下降具有相关性（r = 0.660，P < 0.001）；VM的“V”模式表明α-BRSa功能障碍。然而，与对照组相比，BRSa1未显示出变化（P > 0.05），或在60%的NOH患者中不适用。在有症状的OI患者中，与对照组相比，心血管迷走神经SBP下降幅度更大（P < 0.05）；较高的BRSa1与较高的肾上腺素能指数（自主神经严重程度综合评分）相矛盾。姿势性心动过速综合征患者在IV期的过冲低于基线或在8秒内下降≥10 mmHg（“N”模式），但在不适当窦性心动过速患者中在3秒内下降（“M”模式）。不同VM模式的可视化有助于对自主神经功能障碍进行初步评估，并区分各种形式的OI。病理性SBP模式会影响BRSa1评估。VM模式识别是对HUT的一种有价值的非体位性补充，能够检测和区分OI。
