Abstract 13201: Evaluation of a New High Resolution 4D Echo Based Motion Analysis Program for RV Strain Computation

Abstract

Background: Thin right ventricular (RV) walls and the unique geometry of the RV present challenges in image based evaluation of RV function. We tested the feasibility of a new high resolution DENSE motion analysis program for RV strain computation using full volume 4D image loops.

Methods: Five open chest instrumented pigs were studied under different steady states. Three sonomicrometry crystals were implanted on the RV surface. After acquiring baseline image data, each pig was subjected to epicardial pacing from different ventricular sites (RV, RV outflow tract, left ventricle [LV] and RV apex) allowing compete recovery to regain sinus rhythm after each pacing state. Full volume 4D image loops were acquired at each state with an X7-2 matrix probe on a Phillips IE33 ultrasound system at a frame rate >25 directly from the surface of the heart. Image data was analyzed in an offline high resolution MatLab based motion analysis program for RV strain.

Results: At each state sonomicrometry derived strain values were lower than echo derived strain, but both showed a strong correlation (r = 0.92 for circumferential strain and r = 0.91 for longitudinal strain). Highest strain values were observed longitudinally and in the LV pacing state, whereas RV pacing showed lowest RV strain values. There was minimal angular deformation observed in RV at each steady state.

Conclusion: This new high resolution motion analysis program is feasible for RV strain computation and may provide a useful clinical tool to study RV function.