Hospital of the University of Pennsylvania and University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Institute Biomedical Technology (IBiTech) - bioMMeda Research Group, Ghent University, Gent, Belgium.
Open Heart. 2019 Oct 9;6(2):e001088. doi: 10.1136/openhrt-2019-001088. eCollection 2019.
Non-invasive assessment of left ventricular (LV) diastolic and systolic function is important to better understand physiological abnormalities in heart failure (HF). The spatiotemporal pattern of LV blood flow velocities during systole and diastole can be used to estimate intraventricular pressure differences (IVPDs). We aimed to demonstrate the feasibility of an MRI-based method to calculate systolic and diastolic IVPDs in subjects without heart failure (No-HF), and with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF).
We studied 159 subjects without HF, 47 subjects with HFrEF and 32 subjects with HFpEF. Diastolic and systolic intraventricular flow was measured using two-dimensional in-plane phase-contrast MRI. The Euler equation was solved to compute IVPDs in diastole (mitral base to apex) and systole (apex to LV outflow tract).
Subjects with HFpEF demonstrated a higher magnitude of the early diastolic reversal of IVPDs (-1.30 mm Hg) compared with the No-HF group (-0.78 mm Hg) and the HFrEF group (-0.75 mm Hg; analysis of variance p=0.01). These differences persisted after adjustment for clinical variables, Doppler-echocardiographic parameters of diastolic filling and measures of LV structure (No-HF=-0.72; HFrEF=-0.87; HFpEF=-1.52 mm Hg; p=0.006). No significant differences in systolic IVPDs were found in adjusted models. IVPD parameters demonstrated only weak correlations with standard Doppler-echocardiographic parameters.
Our findings suggest distinct patterns of systolic and diastolic IVPDs in HFpEF and HFrEF, implying differences in the nature of diastolic dysfunction between the HF subtypes.
评估左心室（LV）收缩和舒张功能对于更好地理解心力衰竭（HF）中的生理异常非常重要。收缩期和舒张期 LV 血流速度的时空模式可用于估计室内压力差（IVPD）。我们旨在证明一种基于 MRI 的方法在无心力衰竭（No-HF）、射血分数降低的心力衰竭（HFrEF）和射血分数保留的心力衰竭（HFpEF）患者中计算收缩期和舒张期 IVPD 的可行性。
我们研究了 159 例无 HF 患者、47 例 HFrEF 患者和 32 例 HFpEF 患者。使用二维平面内相位对比 MRI 测量舒张期和收缩期室内血流。通过求解欧拉方程计算舒张期（二尖瓣基底至心尖）和收缩期（心尖至 LV 流出道）的 IVPD。
HFpEF 患者舒张早期 IVPD 的反转幅度（-1.30mmHg）高于 No-HF 组（-0.78mmHg）和 HFrEF 组（-0.75mmHg；方差分析 p=0.01）。这些差异在调整临床变量、舒张期多普勒超声心动图参数和 LV 结构测量值后仍然存在（No-HF=-0.72；HFrEF=-0.87；HFpEF=-1.52mmHg；p=0.006）。调整后的模型中收缩期 IVPD 无显著差异。IVPD 参数与标准多普勒超声心动图参数仅具有弱相关性。
我们的发现表明 HFpEF 和 HFrEF 中存在不同的收缩期和舒张期 IVPD 模式，提示 HF 亚型之间舒张功能障碍的性质存在差异。
