Abstract 13406: Quantification of the Energy Loss in the Left Ventricle Using Color Doppler-Based Vector Flow Mapping in a Dog Model of Aortic Regurgitation
Background: Intracardiac blood flow patterns are potentially important to efficient cardiac pumping. Vector Flow Mapping (VFM®, Hitachi-Aloka Medical) is a novel software based on continuity equation applied to the color Doppler and speckle tracking echocardiography data. It visualizes intracardiac flow and measures energy loss caused by viscous dissipation. Aortic regurgitation (AR) makes turbulent flow thereby possibly increasing energy loss in the left ventricle. The aim of this study was to evaluate quantitatively energy loss in the left ventricular (LV) cavity before and after making AR using VFM.
Methods: AR was made by the distortion of the aortic valve with a catheter inserted into the LV from the right carotid artery of 8 open-chest dogs. Color Doppler images of apical long-axis view were obtained for VFM analysis before and after making AR. Energy loss in the LV cavity was measured frame by frame in one cardiac cycle. Averaged energy loss during diastole, systole and one cardiac cycle were calculated.
Results: Energy loss showed 3 peaks at periods of ejection, early filling and atrial contraction in one cardiac cycle (Figure). Averaged energy loss during diastole, systole and one cardiac cycle were increased significantly by AR (Table).
Conclusions: Energy loss was increased by AR in diastole and systole. Its increase in diastole could be explained by turbulent AR flow and that in systole could be explained by increased forward stroke volume associated with AR. Quantification of energy loss using VFM may be a good tool to assess the effect of AR on the LV.
- © 2013 by American Heart Association, Inc.