Mechanical wave velocity measurement via high-frame-rate echocardiography is feasible with 84-89% interpretability but shows wide normal ranges and no change in subclinical LV dysfunction.
What are the normal ranges of mechanical wave velocities measured by high-frame-rate echocardiography, and can they detect subclinical left ventricular dysfunction in asymptomatic individuals?
While mechanical wave analysis via high-frame-rate echocardiography is feasible, its wide normal ranges and lack of association with subclinical dysfunction limit its current clinical utility for assessing myocardial texture.
Absolute Event Rate: 0% vs 0%
Abstract Background High-frame-rate echocardiography can identify naturally occurring mechanical waves (MW). As the velocity of MW is related to tissue properties, the clinical application of this methodology could address a fundamental shortcoming of echocardiography in the assessment of myocardial texture. Aims To evaluate the feasibility, key determinants, and normal ranges of MW in asymptomatic people. Methods 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. Results Of 209 participants, MW measurements were interpretable in 84% of PLAX and 89% of A4C views. Good agreement was observed between automated and manual measurements, except for velocities 5 m/s. There was poor agreement noted between apical and PLAX view MVC signals, especially with high velocity measurements. In 158 normal participants (defined by normal ejection fraction, global longitudinal strain and estimated atrial pressure), automated 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 (Table). Subclinical LV systolic dysfunction (GLS16%) and elevated LVFP were not associated with changes in MW velocity. Test-retest variability showed little bias within and between observers, but limits of agreement were wide for all measures. Conclusion MW measurement 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.Table 1.Normal ranges by site & method
Sivaraj et al. (Sat,) reported a other. Mechanical wave velocity measurement via high-frame-rate echocardiography is feasible with 84-89% interpretability but shows wide normal ranges and no change in subclinical LV dysfunction.