McClain Shannon L, Brooks Alexa M, Jarvis Sara S
Biological Sciences Department, Northern Arizona University, Flagstaff, AZ, USA.
Int J Exerc Sci. 2017 Mar 1;10(2):188-196. doi: 10.70252/LWDM7489. eCollection 2017.
Controlled or paced breathing is often used as a stress reduction technique but the impact on blood pressure (BP) and sympathetic outflow have not been consistently reported. The purpose of this study was to determine whether a controlled breathing (12 breaths/min, CB) rate would be similar to an individual's spontaneous breathing (SB) rate. Secondly, would a CB rate of 12 breaths/min alter heart rate (HR), BP, and indices of muscle sympathetic nerve activity (MSNA). Twenty-one subjects (10 women, 11 men) performed two trials: SB, where the subject chose a comfortable breathing rate; and CB, where the subject breathed at a pace of 12 breaths/min. Each trial was 6 min during which respiratory waveforms, HR, BP (systolic, SBP; diastolic, DBP), and MSNA were recorded. During CB, the 6 min average breathing frequency (14±4 vs 12±1 breaths/min, <0.05 for SB and CB, respectively), MSNA burst frequency (18±12 vs 14±10 bursts/min, <0.01) and MSNA burst incidence (28±19 vs 21± 6 bursts/100 heart beats, <0.01) were significantly lower than during SB. HR (66±9 vs 67±9 beats/min, <0.05) was higher during CB. SBP (120±13 vs 121±15 mmHg, =0.741), DBP (56±8 vs 57±9 mmHg, =0.768), and MSNA total activity (166±94 vs 145±102 a.u./min, =0.145) were not different between the breathing conditions. In conclusion, an acute reduction in breathing frequency such as that observed during CB elicited a decrease in indices of MSNA (burst frequency and incidence) with no change in BP.
控制性呼吸或节律性呼吸常被用作一种减压技术，但对血压（BP）和交感神经输出的影响尚无一致报道。本研究的目的是确定控制性呼吸频率（12次/分钟，CB）是否与个体的自主呼吸（SB）频率相似。其次，12次/分钟的CB频率是否会改变心率（HR）、血压和肌肉交感神经活动（MSNA）指标。21名受试者（10名女性，11名男性）进行了两项试验：SB试验，受试者选择舒适的呼吸频率；CB试验，受试者以12次/分钟的频率呼吸。每次试验持续6分钟，期间记录呼吸波形、HR、血压（收缩压，SBP；舒张压，DBP）和MSNA。在CB期间，6分钟平均呼吸频率（分别为14±4次/分钟和12±1次/分钟，SB和CB分别<0.05）、MSNA爆发频率（18±12次/分钟和14±10次/分钟，<0.01）和MSNA爆发发生率（28±19次/100次心跳和21±6次/100次心跳，<0.01）显著低于SB期间。CB期间HR较高（66±9次/分钟和67±9次/分钟，<0.05）。呼吸条件之间SBP（120±13 mmHg和121±15 mmHg，=0.741）、DBP（56±8 mmHg和57±9 mmHg，=0.768）和MSNA总活动（166±94任意单位/分钟和145±102任意单位/分钟，=0.145）无差异。总之，如CB期间观察到的呼吸频率急性降低会引起MSNA指标（爆发频率和发生率）降低，而血压无变化。
