Laboratório de Insuficiência Cardíaca e Transplante do Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da USP (InCor HC-FMUSP), São Paulo, Brazil.
Cardiovasc Ther. 2013 Apr;31(2):100-7. doi: 10.1111/j.1755-5922.2011.00297.x. Epub 2011 Aug 3.
The origin of dyspnea in chronic heart failure (HF) is multifactorial, and excessive ventilation is thought to play a role in inducing this symptom. Chemosensivity is augmented in HF, correlates with increased pulmonary ventilation (VE), and is an adverse prognostic marker. Despite increased blood levels of natriuretic peptides in clinical conditions associated with dyspnea, their effect on pulmonary VE and chemoreceptor activity remains unexplored.
We tested in a prospective, placebo-controlled, three-way cross-over, double-blind randomized study the effects of the recombinant form of the natural human B-type natriuretic peptide (R-BNP) in comparison with placebo and levosimendan on chemoreflex sensitivity at rest, as well as their effects on pulmonary VE, systemic blood pressure, heart rate and sympathetic serum activity both at rest and during exercise.
Eleven stable chronic HF patients were randomized to sessions of 6-min treadmill-walking tests during placebo, or levosimendan or R-BNP intravenous infusion in the following conditions: room air, hypoxia, and hypercapnia. R-BNP administration determined higher pulmonary ventilatory response at rest and during exercise (P < 0.001) consequent to a boost of respiratory rate (P < 0.001) under room air and hypoxia conditions. Norepinephrine blood levels increased from rest to exercise in all conditions without differences among placebo, levosimendan, and R-BNP effects. BNP blood levels remained unchanged.
The novelty of the present findings is that R-BNP infusion in HF patients can boost pulmonary ventilatory response at rest and during exercise.
慢性心力衰竭（HF）患者呼吸困难的起源是多因素的，过度通气被认为在诱导这种症状中起作用。HF 患者的化学敏感性增强，与肺通气（VE）增加相关，是预后不良的标志物。尽管与呼吸困难相关的临床情况下血液中利钠肽水平升高，但它们对肺 VE 和化学感受器活性的影响仍未被探索。
我们在一项前瞻性、安慰剂对照、三向交叉、双盲随机研究中测试了重组形式的天然人类 B 型利钠肽（R-BNP）与安慰剂和左西孟旦相比，对静息状态下化学感受器敏感性的影响，以及它们对肺 VE、全身血压、心率和静息和运动期间的交感神经血清活性的影响。
11 例稳定的慢性 HF 患者随机分为安慰剂、左西孟旦或 R-BNP 静脉输注 6 分钟跑步机行走试验，在以下条件下进行：室内空气、低氧和高碳酸血症。R-BNP 给药导致静息和运动时肺通气反应更高（P<0.001），这是由于在室内空气和低氧条件下呼吸频率增加（P<0.001）。在所有条件下，去甲肾上腺素的血液水平从休息到运动都增加，而安慰剂、左西孟旦和 R-BNP 的作用没有差异。BNP 血液水平保持不变。
本研究的新颖之处在于，HF 患者输注 R-BNP 可增强静息和运动时的肺通气反应。
