Taylor Bryan J, Olson Thomas P, Maccarter Dean, Johnson Bruce D
Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
Clin Med Insights Circ Respir Pulm Med. 2013 Sep 22;7:53-60. doi: 10.4137/CCRPM.S12178. eCollection 2013.
We determined whether a non-invasive gas exchange based estimate of pulmonary vascular (PV) capacitance [PVCAP = stroke volume (SV) × pulmonary arterial pressure (Ppa)] (GXCAP) tracked the PV response to exercise in heart-failure (HF) patients. Pulmonary wedge pressure (Ppw), Ppa, PV resistance (PVR), and gas exchange were measured simultaneously during cycle exercise in 42 HF patients undergoing right-heart catheterization. During exercise, PETCO2 and VE/VCO2 were related to each other (r = -0.93, P < 0.01) and similarly related to mean Ppa (mPpa) (r = -0.39 and 0.36; P < 0.05); PETCO2 was subsequently used as a metric of mPpa. Oxygen pulse (O2 pulse) tracked the SV response to exercise (r = 0.91, P < 0.01). Thus, GXCAP was calculated as O2 pulse × PETCO2. During exercise, invasively determined PVCAP and non-invasive GXCAP were related (r = 0.86, P < 0.01), and GXCAP correlated with mPpa and PVR (r = -0.46 and -0.54; P < 0.01). In conclusion, noninvasive gas exchange measures may represent a simple way to track the PV response to exercise in HF.
我们确定了基于无创气体交换的肺血管（PV）容量估计值[PVCAP = 每搏量（SV）×肺动脉压（Ppa）]（GXCAP）是否能追踪心力衰竭（HF）患者运动时的PV反应。在42例接受右心导管检查的HF患者进行周期性运动期间，同时测量肺楔压（Ppw）、Ppa、PV阻力（PVR）和气体交换。运动期间，呼气末二氧化碳分压（PETCO2）与每分通气量/二氧化碳排出量（VE/VCO2）相互相关（r = -0.93，P < 0.01），且与平均Ppa（mPpa）的相关性类似（r = -0.39和0.36；P < 0.05）；随后将PETCO2用作mPpa的指标。氧脉搏（O2脉搏）追踪运动时的SV反应（r = 0.91，P < 0.01）。因此，GXCAP计算为O2脉搏×PETCO2。运动期间，有创测定的PVCAP与无创GXCAP相关（r = 0.86，P < 0.01），且GXCAP与mPpa和PVR相关（r = -0.46和 -0.54；P < 0.01）。总之，无创气体交换测量可能是追踪HF患者运动时PV反应的一种简单方法。
