Sivaraj Eswar, Lovstakken Lasse, Corney Raphaela, Fadnes Solveig, Espeland Torvald, Andresen Kristoffer, Marwick Thomas H
JACC Cardiovasc Imaging. 2025 Aug 22. doi: 10.1016/j.jcmg.2025.08.006.
High-frame-rate echocardiography can identify naturally-occurring mechanical waves (MW). As the velocity of MW is related to tissue properties, this methodology could solve a fundamental shortcoming of echocardiography. However, to be useful clinically, there would need to be limited overlap between the normal range of MW, and measurements associated with pathology such as LV dysfunction and ischemic heart disease.
To evaluate the feasibility, key determinants, and normal ranges of MW in asymptomatic people, and patients with cardiac pathology.
Asymptomatic participants were recruited from a community-based heart failure surveillance program. Clinical evaluation, six-minute walk test, and echocardiography with specialized high-frame-rate imaging were performed. MW signals from atrial kick (AK), aortic valve closure (AVC), and mitral valve closure (MVC) were acquired from parasternal long-axis (PLAX) and apical four-chamber (A4C) windows. Measurements were averaged across three cycles using automated and manual methods, and outliers were removed (AVC and MVC >9 m/s, AK >7 m/s). Participants were classified into normal and abnormal groups based on echocardiographic and clinical parameters.
Of the 239 participants, manual measurement was feasible in 80% for AK-, 77% for AVC- and 77% for MVC-MW in the PLAX view, and 91%, 85% and 62% from the apical view. Manual measurements were more feasible than automated measurements. Clinical and echocardiographic markers of hemodynamics and cardiac function had little or no association with MW velocities. There was poor agreement noted between apical and PLAX view MVC signals, especially with high velocity measurements. In 158 normal participants, MW velocities in PLAX for AVC, MVC and AK were 3.78±1.72, 3.36±1.75, 1.46±0.87 m/s. In A4C, these were 3.32±1.72, 4.14±1.98 and 1.23±0.49 m/s, respectively. Only AK measurements were significantly different between the patients with normal and abnormal echocardiograms. There was little bias within and between observers, but limits of agreement were wide for all measures.
MW measurement - especially AK - is a feasible adjunct to standard echocardiography. However, the normal ranges are wide, even among participants with otherwise normal studies. MW velocities do not seem to be abnormal in subclinical dysfunction.
高帧率超声心动图能够识别自然发生的机械波（MW）。由于MW的速度与组织特性相关，该方法可能解决超声心动图的一个基本缺点。然而，要在临床上有用，MW的正常范围与诸如左心室功能障碍和缺血性心脏病等病理相关测量之间需要有限的重叠。
评估无症状人群以及患有心脏疾病的患者中MW的可行性、关键决定因素和正常范围。
从基于社区的心力衰竭监测项目中招募无症状参与者。进行临床评估、六分钟步行试验以及使用专门的高帧率成像的超声心动图检查。从胸骨旁长轴（PLAX）和心尖四腔心（A4C）切面获取心房收缩（AK）、主动脉瓣关闭（AVC）和二尖瓣关闭（MVC）的MW信号。使用自动和手动方法对三个心动周期的测量值进行平均，并去除异常值（AVC和MVC>9 m/s，AK>7 m/s）。根据超声心动图和临床参数将参与者分为正常组和异常组。
在239名参与者中，在PLAX切面，AK-MW的手动测量在80%的参与者中可行，AVC-MW为77%，MVC-MW为77%；在心尖切面分别为91%、85%和62%。手动测量比自动测量更可行。血流动力学和心脏功能的临床及超声心动图标志物与MW速度几乎没有关联。在心尖和PLAX切面的MVC信号之间一致性较差，尤其是高速测量时。在158名正常参与者中，PLAX切面中AVC、MVC和AK的MW速度分别为3.78±1.72、3.36±1.75、1.46±0.87 m/s。在A4C切面，这些速度分别为3.32±1.72、4.14±1.98和1.23±0.49 m/s。只有AK测量值在超声心动图正常和异常的患者之间有显著差异。观察者内部和之间的偏差较小，但所有测量的一致性界限较宽。
MW测量——尤其是AK——是标准超声心动图的一种可行辅助手段。然而，即使在其他检查正常的参与者中，正常范围也较宽。亚临床功能障碍时MW速度似乎并无异常。
