Larson Mia, Chantigian Daniel P, Asirvatham-Jeyaraj Ninitha, Van de Winckel Ann, Keller-Ross Manda L
Division of Rehabilitation Science, Department of Rehabilitation Medicine, Medical School, University of Minnesota, Minneapolis, MN, United States.
Indian Institute of Science, Bangalore, India.
Front Physiol. 2020 Oct 30;11:573325. doi: 10.3389/fphys.2020.573325. eCollection 2020.
: To determine if acute slow breathing at 6 breaths/min would improve baroreflex sensitivity (BRS) and heart rate variability (HRV), and lower blood pressure (BP) in adults after stroke. : Twelve individuals completed two randomized study visits where they performed a 15-min bout of breathing exercises at 6 breaths/min (slow) and at 12 breaths/min (control). Continuous BP and heart rate (HR) were measured throughout, and BRS, BRS response to elevations in blood pressure (BRSup), BRS response to depressions in blood pressure (BRSdown), and HRV were calculated and analyzed before (pre), during, and after (post) breathing exercises. : BRS increased from pre to post slow breathing by 10% ( = 0.012), whereas BRSup increased from pre to during slow breathing by 30% ( = 0.04). BRSdown increased from pre to post breathing for both breathing conditions ( < 0.05). HR (control: - 4 ± 4; slow: - 3 ± 4 beats/min, time, < 0.01) and systolic BP (control: - 0.5 ± 5; slow: - 6.3 ± 8 mmHg, time, < 0.01) decreased after both breathing conditions. Total power, low frequency power, and standard deviation of normal inter-beat intervals (SDNN) increased during the 6-breaths/min condition (condition × time, < 0.001), whereas high frequency increased during both breathing conditions (time effect, = 0.009). : This study demonstrated that in people post-stroke, slow breathing may increase BRS, particularly BRSup, more than a typical breathing space; however, paced breathing at either a slow or typical breathing rate appears to be beneficial for acutely decreasing systolic BP and HR and increasing HRV.
确定中风后成年人以每分钟6次呼吸的频率进行急性慢呼吸是否会改善压力反射敏感性（BRS）、心率变异性（HRV）并降低血压（BP）。
12名个体完成了两次随机研究访视，期间他们分别以每分钟6次呼吸（慢呼吸）和每分钟12次呼吸（对照）的频率进行了15分钟的呼吸练习。在整个过程中持续测量血压和心率（HR），并在呼吸练习前（pre）、期间和之后（post）计算和分析BRS、对血压升高的BRS反应（BRSup）、对血压降低的BRS反应（BRSdown）以及HRV。
慢呼吸后BRS较呼吸前增加了10%（P = 0.012），而慢呼吸期间BRSup较呼吸前增加了30%（P = 0.04）。两种呼吸条件下BRSdown在呼吸后均较呼吸前增加（P < 0.05）。两种呼吸条件后HR（对照：-4 ± 4；慢呼吸：-3 ± 4次/分钟，时间，P < 0.01）和收缩压（对照：-0.5 ± 5；慢呼吸：-6.3 ± 8 mmHg，时间，P < 0.01）均降低。在每分钟6次呼吸的条件下，总功率、低频功率和正常心跳间期标准差（SDNN）增加（条件×时间，P < 0.001），而在两种呼吸条件下高频功率均增加（时间效应，P = 0.009）。
本研究表明，在中风患者中，慢呼吸可能比典型呼吸更能增加BRS，尤其是BRSup；然而，无论是慢呼吸还是典型呼吸频率的节律性呼吸似乎都有利于急性降低收缩压和心率并增加HRV。
