De Maria Beatrice, Bari Vlasta, Cairo Beatrice, Vaini Emanuele, Martins de Abreu Raphael, Perseguini Natalia Maria, Milan-Mattos Juliana, Rehder-Santos Patricia, Minatel Vinícius, Catai Aparecida Maria, Dalla Vecchia Laura Adelaide, Porta Alberto
Istituto di Ricovero e Cura a Carattere Scientifico Istituti Clinici Scientifici Maugeri, Milan, Italy.
Department of Cardiothoracic, Vascular Anesthesia, and Intensive Care, Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Donato, San Donato Milanese, Milan, Italy.
Am J Physiol Regul Integr Comp Physiol. 2019 Oct 1;317(4):R539-R551. doi: 10.1152/ajpregu.00112.2019. Epub 2019 Jul 31.
In heart period (HP) variability (HPV) recordings the percentage of negative HP variations tends to be greater than that of positive ones and this pattern is referred to as HPV asymmetry (HPVA). HPVA has been studied in several experimental conditions in healthy and pathological populations, but its origin is unclear. The baroreflex (BR) exhibits an asymmetric behavior as well given that it reacts more importantly to positive than negative arterial pressure (AP) variations. We tested the hypothesis that the BR asymmetry (BRA) is a HPVA determinant over spontaneous fluctuations of HP and systolic AP (SAP). We studied 100 healthy subjects (age from 21 to 70 yr, 54 men) comprising 20 subjects in each age decade. Electrocardiogram and noninvasive AP were recorded for 15 min at rest in supine position (REST) and during active standing (STAND). The HPVA was evaluated via Porta's index and Guzik's index, while the BRA was assessed as the difference, and normalized difference, between BR sensitivities computed over positive and negative SAP variations via the sequence method applied to HP and SAP variability. HPVA significantly increased during STAND and decreased progressively with age. BRA was not significantly detected both at REST and during STAND. However, we found a significant positive association between BRA and HPVA markers during STAND persisting even within the age groups. This study supports the use of HPVA indexes as descriptors of BRA and identified a challenge soliciting the BR response like STAND to maximize the association between HPVA and BRA markers.
在心动周期（HP）变异性（HPV）记录中，负向HP变异的百分比往往大于正向变异，这种模式被称为HPV不对称性（HPVA）。HPVA已在健康和病理人群的多种实验条件下进行了研究，但其起源尚不清楚。压力反射（BR）也表现出不对称行为，因为它对正向动脉压（AP）变化的反应比负向变化更重要。我们检验了这样一个假设，即BR不对称性（BRA）是HP和收缩压（SAP）自发波动时HPVA的一个决定因素。我们研究了100名健康受试者（年龄在21至70岁之间，54名男性），每个年龄十年包含20名受试者。在仰卧位休息（REST）和主动站立（STAND）期间记录心电图和无创AP 15分钟。通过Porta指数和Guzik指数评估HPVA，而通过应用于HP和SAP变异性的序列方法计算正向和负向SAP变异时的BR敏感性之间的差异和标准化差异来评估BRA。HPVA在STAND期间显著增加，并随年龄逐渐降低。在REST和STAND期间均未显著检测到BRA。然而，我们发现在STAND期间，BRA与HPVA标志物之间存在显著的正相关，甚至在各年龄组内这种相关性仍然存在。本研究支持使用HPVA指数作为BRA的描述指标，并确定了一种像STAND这样激发BR反应的挑战，以最大化HPVA与BRA标志物之间的相关性。
