Abstract 17079: Pattern and Regional Variability of Left Ventricular Cavity Remodeling in Various Loading Condition: 3D Echocardiographic Analysis

Introduction: LV internal dimension (LVID) measured at the basal level is used to follow LV adaptation to pressure or volume load. However, this single dimension method is subject to high variability and may not reflect LV changes due to differential LV remodeling. We aimed to perform detailed 3D analysis of LV shape to highlight differential LV remodeling, in order to optimize existing 2D measures. Methods: 90 patients were analyzed and grouped based on type of LV overload (20 severe aortic stenosis (AS), 20 dilated cardiomyopathy (DCM), 15 severe aortic regurgitation (AR), 15 severe mitral regurgitation (MR) and 20 normal). Regional variations in LV cavity pattern was identified from 3D images by calculating LVID using summation of radii at every 3 degrees of rotational angle at 100 positions along the LV long axis. The rotational angle (X-axis) was mapped as a function of the position along the LV from base to apex (Y-axis), to obtain a color map representation of regional LV changes based on LVID changes (Fig left). Position from base to apex was grouped into quintiles and standard deviations (SD) of LVID at each position calculated. Results: All groups, including normal, consistently showed the greatest variation in measured LVIDs within the 1st quintile position (1-20; basal level) and the least variation within the 3rd quintile position (41-60; mid ventricle)(3.03±0.97mm vs 1.96±0.88mm; p<0.001; Fig right). The variation in the 1st quintile is greater in the presence of LV overload with pressure overload (AS) showing the most variation. Importantly, Quintile 1 had significantly lower correlation with LV volume than Quintile 2-4 (R2=0.77 vs R2=0.88-0.91; p<0.001). Conclusion: LVID measurements made within the the basal portion of the LV was subject to greatest variability particularly in the presence of LV overload. However measurements made at the mid-ventricular level are more likely to be reproducible and show better correlation with volumes. ![][1] [1]: /embed/graphic-1.gif