Objective: This in vitro study calculated longitudinal strain (LS) from different ultrasound systems (GE Vivid E9 and Philips IE 33) before and after myocardial infarct (MI) using a vendor-independent analysis software package (TomTec's 4D LV Analysis) to validate the variation of two ultrasound systems.
Methods: Ten freshly harvested porcine hearts were passively driven by a pulsatile pump apparatus at stroke volumes (SV) 30-70 mL. Full-volume three-dimensional echocardiography (3DE) data were acquired before and after MI using two different ultrasound systems. LS was derived from TomTec and validated against sonomicrometry data.
Results: Linear regression analyses showed excellent correlations between TomTec-calculated LS values and sonomicrometry data for both normal and simulated MI groups (GE: R2 = 0.72/0.68, Philip: R2 = 0.71/0.66). Bland-Altman analyses demonstrated overestimation of echo-derived strain values for all groups. Both ultrasound system-derived strain values demonstrated decreased LS after MI, and the average change in strain after infarct was roughly 30% in GE images and 25% in Philips images.
Conclusions: Both GE and Philips echocardiographic systems can be analyzed with TomTec's program, and these images correlated well with sonomicrometry with acceptable variations.
Keywords: longitudinal strain values; three-dimensional speckle-tracking echocardiography.
© 2018 Wiley Periodicals, Inc.