Abstract 1871: Usefulness of Three-Dimensional Echocardiographic Parametric Quantification of Regional Left Ventricular Function: a Feasibility Study
Introduction: Recently, a novel technique based on real-time three-dimensional echocardiography (RT3DE) has been developed, by which the extension and timing of mechanical myocardial activity are displayed on color chart as a function of time.
Hypothesis: We hypothesized that RT3DE can accurately quantify 3D regional left ventricular (LV) volume changes and radial myocardial displacement as compared to cardiac magnetic resonance imaging (CMR).
Methods: We tested RT3DE endocardial border detection algorithm aiming at:
validation of the RT3DE-derived time-volume curves (TVCs) against CMR-derived TVCs from the LV(2) assessment of the variability of regional LV function in HF patients against healthy volunteers
to test inter- and intra-observer agreement of RT3DE-color parametric display of LV volume and radial displacement dynamic (timing and extent) information
The study included three protocols, which were performed in 108 subjects (55 ± 14 yr, 71 males), including 32 healthy volunteers (41 ± 13 years, 22 men). All patients underwent RT3DE and a subgroup of 20 patients (with good 2D image quality) underwent the same day CMR to ensure comparable hemodynamic conditions. In protocol 1, in each patient, TVC from one cardiac cycle was divided into 24 sub-volumes, which resulted in 480 sub-volumes to avoid clustering of data within the same patient. Then, linear regression and Bland-Altman analyses were applied. In protocol 3, RT3DE data from 40 randomly selected subjects were re-analyzed by the primary observer and by a second observer.
Results: Point-by-point volume from RT3DE TVCs correlated highly with MRI (r = 0.96; y=0.92x + 4.7) with minimal bias (2.5 mL) and narrow limits of agreement (± 12 mL). Radial excursions derived from RT3DE correlated highly with MRI (r = 0.84; y = 0.80x + 1.3). SD of time-to-minimum systolic volume in HF patients was 11.2 3 8.6 vs. 3.2% ± 3.1 in healthy volunteers. Excellent inter- and intra-observer agreement >90% for regional volume and radial excursions were found. Definition of site of latest activation on color-maps showed high inter-observer agreement (k=0.87).
Conclusion: RT3DE provides simple, reproducible and accurate assessment of global and regional LV volume and wall motion.