Abstract 14786: Effect of Left Ventricular Dyssynchrony on Vortex Formation Assessed With Vector Flow Mapping
Background: Vortex in the left ventricle (LV) has been suggested to contribute to effective blood transport. Since vortex formation during diastole is influenced by LV structure and function, its quantitative evaluation may serve as a novel parameter of LV function. LV dyssynchrony decreases cardiac pump function causing heart failure. However, it remains unclear how vortex formation is changed by dyssynchrony. Vector flow mapping (VFM, Hitachi) is a novel echocardiographic technology which enables visualization and quantification of the intraventricular flow using color Doppler and speckle tracking algorithm. We investigated the change of vortex formation by LV dyssynchrony with VFM.
Methods: Right ventricular (RV) pacing was performed on 10 open-chest dogs to create LV dyssynchrony and right atrial (RA) pacing was performed on another 10 open-chest dogs to investigate the effect of increasing heart rate. Apical long-axis color Doppler and 2D images were obtained before and after each pacing. Diastolic maximum vortex size corrected for LV size and circulation were measured by VFM. The time difference (TD) between longitudinal peak strain of mid inferolateral and apical anterior segments were analyzed to evaluate LV dyssynchrony.
Results: Mean pacing rate was 153±9 ppm in RV pacing and 152±3 ppm in RA pacing (p=ns). TD significantly prolonged by RV pacing (baseline vs. RV pacing: -57±99 vs. 44±90 ms, p<0.05) confirming successful creation of LV dyssynchrony. Vortex size did not change and circulation tended to increase after RA pacing. However, vortex size and circulation significantly decreased by RV pacing even with a similar pacing rate (Figure).
Conclusion: Vortex size and circulation were decreased by LV dyssynchrony, suggesting that LV dyssynchrony impeded effective blood transport in diastole.
Author Disclosures: T. Kamimukai: None. K. Masuda: None. H. Adachi: None. Y. Sakakibara: None. M. Stugaard: None. T. Asanuma: None. S. Nakatani: Honoraria; Significant; Edwards Lifesciences Inc..
- © 2016 by American Heart Association, Inc.