Sano Hiroyuki, Tanaka Hidekazu, Motoji Yoshiki, Mukai Jun, Suto Makiko, Takada Hiroki, Soga Fumitaka, Hatani Yutaka, Matsuzoe Hiroki, Hatazawa Keiko, Shimoura Hiroyuki, Ooka Junichi, Nakayama Kazuhiko, Matsumoto Kensuke, Yamada Hirotsugu, Emoto Noriaki, Hirata Ken-Ichi
Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Department of Community Medicine for Cardiology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan.
Echocardiography. 2018 Dec;35(12):1997-2004. doi: 10.1111/echo.14161. Epub 2018 Oct 16.
Pulmonary hypertension (PH) is characterized by marked and sustained elevation of pulmonary vascular resistance and pulmonary artery pressure, and subsequent right-sided heart failure. Right ventricular (RV) function and exercise capacity have been recognized as important prognostic factors for PH. Our aim was to investigate RV contractile reserve and exercise capacity during a leg-positive pressure (LPP) maneuver.
The study population comprised 43 PH patients and 17 normal controls. All patients underwent echocardiography at rest and during LPP stress. Exercise capacity was assessed by 6-minute walk distance for PH patients. RV relative wall thickness was calculated from dividing by RV free wall thickness by basal RV linear dimensions at end-diastole. RV function was calculated by averaging peak speckle-tracking longitudinal strain from the RV free wall. RV contractile reserve was assessed as the difference in RV free wall strain at rest and during LPP stress. Changes in left ventricular stroke volume (ΔSV) during LPP stress were also calculated.
ΔSV and RV contractile reserve of PH patients were significantly lower than of controls (3.6 ± 6.0 mL vs 8.5 ± 2.3 mL, and 8.2 ± 11.9% vs 14.5 ± 6.6%; both P < 0.01). RV contractile reserve of PH patients with ΔSV <3.3 mL was significantly lower than of PH patients with ΔSV >3.3 mL (3.9 ± 13.2% vs 12.3 ± 8.9%; P = 0.02). ΔSV had also significant correlation with 6-minute walk distance (r = 0.42, P = 0.006). Multivariate regression analysis showed that RV relative wall thickness was an independent determinant parameter of ΔSV during LPP stress for PH patients (β = 3.2, P = 0.003).
Preload stress echocardiography in response to LPP maneuver, a noninvasive and easy-to-use procedure for routine clinical use, proved to be useful for the assessment of RV contractile reserve and exercise capacity of PH patients.
肺动脉高压（PH）的特征是肺血管阻力和肺动脉压力显著持续升高，继而导致右心衰竭。右心室（RV）功能和运动能力已被公认为是PH的重要预后因素。我们的目的是研究腿部正压（LPP）操作期间的RV收缩储备和运动能力。
研究人群包括43例PH患者和17名正常对照者。所有患者在静息状态和LPP应激期间均接受了超声心动图检查。通过PH患者的6分钟步行距离评估运动能力。RV相对壁厚度通过舒张末期RV游离壁厚度除以基础RV线性尺寸来计算。RV功能通过平均RV游离壁的峰值斑点追踪纵向应变来计算。RV收缩储备评估为静息状态和LPP应激期间RV游离壁应变的差值。还计算了LPP应激期间左心室每搏输出量（ΔSV）的变化。
PH患者的ΔSV和RV收缩储备显著低于对照组（3.6±6.0 mL对8.5±2.3 mL，以及8.2±11.9%对14.5±6.6%；均P<0.01）。ΔSV<3.3 mL的PH患者的RV收缩储备显著低于ΔSV>3.3 mL的PH患者（3.9±13.2%对12.3±8.9%；P=0.02）。ΔSV也与6分钟步行距离显著相关（r=0.42，P=0.006）。多变量回归分析表明，RV相对壁厚度是PH患者LPP应激期间ΔSV的独立决定参数（β=3.2，P=0.003）。
响应LPP操作的负荷应激超声心动图是一种无创且易于在常规临床中使用的方法，被证明对评估PH患者的RV收缩储备和运动能力有用。
