Background: Although systolic right ventricular (RV) dysfunction has been shown to be a potent predictor for adverse outcomes in patients with heart failure with preserved ejection fraction (HFpEF), RV functional abnormalities in the course of the syndrome are not well characterized. We, therefore, sought to assess load-independent and load-dependent systolic and diastolic characteristics of RV function in stable outpatients with HFpEF.

Methods and Results: We invasively obtained RV and left ventricular pressure–volume loops in 24 HFpEF patients and 9 patients without heart failure symptoms with a conductance catheter during basal conditions and handgrip exercise. Transient preload reduction was used to extrapolate the RV end-systolic elastance and diastolic stiffness constant. HFpEF patients and controls showed similar left ventricular and RV dimensions and ejection fractions with elevated left ventricular filling pressures. In HFpEF patients, invasively determined load-independent RV contractility (P=0.04) and load-independent passive RV stiffness constant β (P<0.01) were elevated. Although RV relaxation and cardiac output were similar at baseline, HFpEF patients demonstrated a blunted increase in cardiac output under exercise (P=0.01) associated with prolonged RV relaxation (P=0.01), decrease in stroke volume (P<0.01), higher RV-filling pressures (P<0.01), and a marked increase in the end-diastolic pressure–volume relationship (P<0.01).

Conclusions: In compensated stages of the HFpEF syndrome, systolic RV function is preserved, but diastolic abnormalities with intrinsic RV stiffness and prolonged RV relaxation are already present. Impaired diastolic RV reserve contributes to a blunted increase in cardiac output during exertion. Because impairments in diastolic function seem to be a biventricular phenomenon, RV diastolic dysfunction warrants further consideration when characterizing HFpEF patients.

Clinical Trial Registration: https://www.clinicaltrials.gov. Unique identifier: NCT02459626.

背景：尽管已证明收缩期右心室（RV）功能障碍是射血分数（HFpEF）保持不变的心力衰竭患者不良结局的有效预测指标，但该综合征过程中RV功能异常的特征尚未明确。因此，我们寻求评估稳定的HFpEF门诊患者右室功能的负荷独立和负荷独立的收缩和舒张特征。

方法和结果：我们在基础情况和握力训练中，用电导导管侵入性获得了RVpEF患者和24例HFpEF患者和9例无心力衰竭症状的患者的RV和左心室压力循环。暂时性预紧力降低用于推断右室收缩末期弹性和舒张期刚度常数。HFpEF患者和对照组表现出相似的左心室和RV尺寸以及射血分数，左心室充盈压升高。在HFpEF患者中，侵入性确定独立于负荷的RV收缩力（P = 0.04）和独立于负荷的被动RV刚度常数β（P<0.01）升高。尽管基线时RV松弛和心输出量相似，但HFpEF患者在运动中心输出量的钝化（P = 0.01）与RV松弛时间延长（P = 0.01），中风量减少（P <0.01），RV较高充盈压（P <0.01），舒张末期压力与容积的关系显着增加（P <0.01）。

结论：在HFpEF综合征的代偿期，收缩期RV功能得以保留，但已出现舒张功能异常，内在RV僵硬和长时间RV松弛。舒张期RV储备受损会导致运动过程中心输出量的钝性增加。由于舒张功能受损似乎是双心室现象，因此在表征HFpEF患者时应进一步考虑RV舒张功能异常。

临床试验注册： https ： //www.clinicaltrials.gov。唯一标识符：NCT02459626。