Abstract 2924: Assessment of Left Ventricular Torsion By Real-time 3-Dimensional Velocity Vector Imaging in Normals and Patients With Left Ventricular Hypertrophy
Background: LV twist and torsion are best measured in 3-D. We studied the feasibility of Velocity Vector Imaging (VVI, Siemens, CA) to quantify twist and torsion by real-time transthoracic 3-D echocardiography (TTE - 3DE).
Methods: Real time TTE-3DE was done in 9 normals and 9 patients with hypertensive LVH) using a Sequoia system, (Siemens, CA). Serial short-axis views (SAX) and three long-axis (LAX) MPRs were generated to which VVI was applied. The difference between apical and basal rotations (φapex-φbase) yielded LV twist. LV torsion was calculated as twist normalized to the length (L, cm) of the LV: φapex-φbase/L. All parameters were displayed on a 3-D buetel as well as graphs and Bull’s-eyes color maps.
Results: (Table⇓) LVH patients had normal 3-D EF and impaired E/A ratio, table⇓. Serial SAX (figure⇓) and LAX MPRs (figure⇓) were generated successfully from all data sets. Basal rotation was comparable in the 2 groups whereas apical rotation was higher (12%) in the LVH group. 3D LV twist and torsion was also higher by 39% and 81% respectively, in the LVH group. Time to peak torsion was shorter in the LVH group. Thus, the LVH group showed an augmentation of LV torsional dynamics consistent with LVH and normal EF.
Conclusion: Real-time 3DE VVI is feasible and provides quantitative LV torsional data for comprehensive assessment of myocardial mechanics.