Laboratório de Fisiologia, Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal de Ciências da Saúdede Porto Alegre, Brazil.
J Appl Physiol (1985). 2011 Dec;111(6):1664-70. doi: 10.1152/japplphysiol.01245.2010. Epub 2011 Sep 8.
Respiratory muscle training (RMT) improves functional capacity in chronic heart-failure (HF) patients, but the basis for this improvement remains unclear. We evaluate the effects of RMT on the hemodynamic and autonomic function, arterial baroreflex sensitivity (BRS), and respiratory mechanics in rats with HF. Rats were assigned to one of four groups: sedentary sham (n = 8), trained sham (n = 8), sedentary HF (n = 8), or trained HF (n = 8). Trained animals underwent a RMT protocol (30 min/day, 5 day/wk, 6 wk of breathing through a resistor), whereas sedentary animals did not. In HF rats, RMT had significant effects on several parameters. It reduced left ventricular (LV) end-diastolic pressure (P < 0.01), increased LV systolic pressure (P < 0.01), and reduced right ventricular hypertrophy (P < 0.01) and pulmonary (P < 0.001) and hepatic (P < 0.001) congestion. It also decreased resting heart rate (HR; P < 0.05), indicating a decrease in the sympathetic and an increase in the vagal modulation of HR. There was also an increase in baroreflex gain (P < 0.05). The respiratory system resistance was reduced (P < 0.001), which was associated with the reduction in tissue resistance after RMT (P < 0.01). The respiratory system and tissue elastance (Est) were also reduced by RMT (P < 0.01 and P < 0.05, respectively). Additionally, the quasistatic Est was reduced after RMT (P < 0.01). These findings show that a 6-wk RMT protocol in HF rats promotes an improvement in hemodynamic function, sympathetic and vagal heart modulation, arterial BRS, and respiratory mechanics, all of which are benefits associated with improvements in cardiopulmonary interaction.
呼吸肌训练（RMT）可改善慢性心力衰竭（HF）患者的功能能力，但改善的基础仍不清楚。我们评估了 RMT 对 HF 大鼠血流动力学和自主神经功能、动脉压力反射敏感性（BRS）和呼吸力学的影响。大鼠被分为四组之一：安静假手术（n = 8）、训练假手术（n = 8）、安静 HF（n = 8）或训练 HF（n = 8）。训练动物接受 RMT 方案（30 分钟/天，每周 5 天，6 周通过电阻器呼吸），而安静动物则不接受。在 HF 大鼠中，RMT 对多个参数有显著影响。它降低了左心室（LV）舒张末期压（P < 0.01），增加了 LV 收缩压（P < 0.01），并减少了右心室肥大（P < 0.01）和肺（P < 0.001）和肝（P < 0.001）充血。它还降低了静息心率（HR；P < 0.05），表明 HR 的交感神经调制降低，迷走神经调制增加。BRS 增益也增加（P < 0.05）。呼吸系统阻力降低（P < 0.001），这与 RMT 后组织阻力降低（P < 0.01）有关。呼吸系统和组织弹性（Est）也通过 RMT 降低（P < 0.01 和 P < 0.05），分别。此外，RMT 后准静态 Est 降低（P < 0.01）。这些发现表明，HF 大鼠 6 周 RMT 方案可改善血流动力学功能、交感神经和迷走神经心脏调节、动脉 BRS 和呼吸力学，所有这些都与心肺相互作用的改善有关。
