Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden.
Department of Cardiology, Clinical Sciences, Lund University, Skåne University Hospital, Lund, Sweden.
J Appl Physiol (1985). 2022 Sep 1;133(3):697-709. doi: 10.1152/japplphysiol.00257.2022. Epub 2022 Aug 29.
Kinetic energy (KE) of intracardiac blood flow reflects myocardial work spent on accelerating blood and provides a mechanistic window into diastolic filling dynamics. Diastolic dysfunction may represent an early stage in the development of heart failure (HF). Here we evaluated the hemodynamic effects of impaired diastolic function in subjects with and without HF, testing the hypothesis that left ventricular KE differs between controls, subjects with subclinical diastolic dysfunction (SDD), and patients with HF. We studied 77 subjects [16 controls, 20 subjects with SDD, 16 heart failure with preserved ejection fraction (HFpEF), 9 heart failure with mildly reduced ejection fraction (HFmrEF), and 16 heart failure with reduced ejection fraction (HFrEF) patients, age- and sex-matched at the group level]. Cardiac magnetic resonance at 1.5 T included intracardiac four-dimensional (4-D) flow and cine imaging. Left ventricular KE was calculated as 0.5 × × . Systolic KE was similar between groups ( > 0.4), also after indexing to stroke volume ( = 0.25), and was primarily driven by ventricular emptying rate ( < 0.0001, = 0.52). Diastolic KE was higher in patients with heart failure than in controls ( < 0.05) but similar between SDD and HFpEF ( > 0.18), correlating with inflow conditions (E-wave velocity, < 0.0001, = 0.24) and end-diastolic volume ( = 0.0003, = 0.17) but not with average ' ( = 0.07). Diastolic KE differs between controls and heart failure, suggesting more work is spent filling the failing ventricle, whereas systolic KE does not differentiate between well-matched groups with normal ejection fractions even in the presence of relaxation abnormalities and heart failure. Mechanistically, KE reflects the acceleration imparted on the blood and is driven by variations in ventricular emptying and filling rates, volumes, and heart rate, regardless of underlying pathology. Here we present the first study of left ventricular kinetic energy in individuals with subclinical diastolic dysfunction and in heart failure patients with preserved or impaired systolic function. Kinetic energy differs between groups in diastole, and reflects altered filling and emptying processes. Kinetic energy analysis should be considered in studies seeking to characterize myocardial energetics comprehensively.
心脏血流的动能（KE）反映了心肌加速血液所消耗的能量，并为舒张期充盈动力学提供了一个机械性的窗口。舒张功能障碍可能代表心力衰竭（HF）发展的早期阶段。在这里，我们评估了有和没有 HF 的舒张功能障碍受试者的血液动力学影响，检验了左心室 KE 在对照组、亚临床舒张功能障碍（SDD）受试者和 HF 患者之间存在差异的假设。我们研究了 77 名受试者[16 名对照者、20 名 SDD 受试者、16 名射血分数保留的心力衰竭（HFpEF）患者、9 名射血分数轻度降低的心力衰竭（HFmrEF）患者和 16 名射血分数降低的心力衰竭（HFrEF）患者，按组在年龄和性别上进行匹配]。在 1.5T 的心脏磁共振中包括心内四维（4-D）流和电影成像。左心室 KE 的计算方法为 0.5 × × 。各组之间的收缩期 KE 相似（>0.4），在索引到每搏量后也是如此（=0.25），主要由心室排空率驱动（<0.0001，=0.52）。心力衰竭患者的舒张期 KE 高于对照组（<0.05），但 SDD 和 HFpEF 之间相似（>0.18），与流入条件（E 波速度，<0.0001，=0.24）和舒张末期容积（=0.0003，=0.17）相关，但与平均 '无关（=0.07）。舒张期 KE 在对照组和心力衰竭患者之间存在差异，提示衰竭心室的充盈需要更多的能量，而收缩期 KE 即使在存在舒张功能异常和心力衰竭的情况下，也不能区分射血分数正常的匹配良好的组。从机制上讲，KE 反映了施加在血液上的加速度，并且受到心室排空和充盈速率、容积和心率变化的驱动，而与潜在的病理学无关。在这里，我们首次在亚临床舒张功能障碍个体和射血分数保留或受损的心力衰竭患者中研究了左心室动能。KE 在舒张期存在组间差异，反映了充盈和排空过程的改变。在全面描述心肌能量学的研究中，应考虑动能分析。
