Zamunér Antonio Roberto, Porta Alberto, Andrade Carolina Pieroni, Marchi Andrea, Forti Meire, Furlan Raffaello, Barbic Franca, Catai Aparecida Maria, Silva Ester
Department of Physical Therapy, Federal University of São Carlos, São Carlos, Brazil;
Department of Biomedical Sciences for Health, University of Milan, Milan, Italy; Istituti di Ricovero e Cura a Carattere Scientifico Galeazzi Orthopedic Institute, Milan, Italy;
Am J Physiol Regul Integr Comp Physiol. 2015 Jul 1;309(1):R79-84. doi: 10.1152/ajpregu.00012.2015. Epub 2015 Apr 22.
The cardiovascular autonomic control and the baroreflex sensitivity (BRS) have been widely studied in fibromyalgia syndrome (FMS) patients through the computation of linear indices of spontaneous heart period (HP) and systolic arterial pressure (SAP) variabilities. However, there are many methodological difficulties regarding the quantification of BRS by the traditional indices especially in relation to the issue of causality. This difficulty has been directly tackled via a model-based approach describing the closed-loop HP-SAP interactions and the exogenous influences of respiration. Therefore, we aimed to assess whether the BRS assessed by the model-based causal closed-loop approach during supine and active standing in patients with FMS could provide complementary information to those obtained by traditional indices based on time and frequency domains. The findings of this study revealed that, at difference with the traditional methods to quantify BRS, the causality analysis applied to the HP, SAP, and respiratory series, through the model-based closed-loop approach, detected lower BRS in supine position, as well as a blunted response to the orthostatic stimulus in patients with FMS compared with healthy control subjects. Also, the strength of the causal relation from SAP to HP (i.e., along the cardiac baroreflex) increased during the active standing only in the control subjects. The model-based closed-loop approach proved to provide important complementary information about the cardiovascular autonomic control in patients with FMS.
通过计算自发性心动周期（HP）和收缩期动脉压（SAP）变异性的线性指标，心血管自主神经控制和压力反射敏感性（BRS）已在纤维肌痛综合征（FMS）患者中得到广泛研究。然而，使用传统指标对BRS进行量化存在许多方法上的困难，尤其是在因果关系问题方面。通过一种基于模型的方法直接解决了这一困难，该方法描述了闭环HP-SAP相互作用以及呼吸的外源性影响。因此，我们旨在评估基于模型的因果闭环方法在FMS患者仰卧位和主动站立期间评估的BRS是否能为基于时域和频域的传统指标所获得的信息提供补充。本研究结果显示，与量化BRS的传统方法不同，通过基于模型的闭环方法对HP、SAP和呼吸序列进行因果分析发现，FMS患者在仰卧位时BRS较低，并且与健康对照受试者相比，对直立刺激的反应减弱。此外，仅在对照受试者中，主动站立期间从SAP到HP的因果关系强度（即沿心脏压力反射）增加。基于模型的闭环方法被证明能为FMS患者的心血管自主神经控制提供重要的补充信息。
