Abstract 17418: Vector Velocity Imaging: A Reliable Tool to Quantify Myocardial Function and Predict Clinical Outcomes in Single Ventricle Patients
Background: Ventricular function is one of the factors that correlate with survival to second stage surgical palliation in single ventricle (SV) patients. Standard 2D echocardiography (2DE) has limitations in evaluating right ventricular function. Myocardial function can be reliably determined using Vector Velocity Imaging (VVI), which is an angle independent method of evaluating myocardial mechanics using conventional 2DE images.
HYPOTHESIS: VVI provides a valid and reproducible measure of ventricular function in SV patients compared to standard 2DE with direct correlation to clinical outcomes.
Methods: Medical records and 2DE's were retrospectively reviewed on 72 patients with SV's (37 systemic right ventricles, 35 systemic left ventricles. VVI analysis was performed offline using Siemens Syngo software. When feasible, 2D and Doppler parameters of ventricular function were performed. Using VVI on a 4 chamber image longitudinal velocity (LVel), strain (S), strain rate (SR) were obtained. Ventricular function was measured pre and post stage 1 palliation and compared to normals.
Results: Fifty seven patients survived to stage 2 palliation (79%). Of the 15 deceased, 10 survived to hospital discharge; 10 had a single RV and 5 had single LV. Heterotaxy, post operative ECMO, sepsis, atrioventricular valve insufficiency and chylothorax were factors associated with death. Using 2DE, ventricular function was qualitatively normal in all but 3 patients pre-stage 1 and in 9 patients post stage 1. Other quantitative parameters were not consistently employed through the study period. LVel, S, and SR were depressed compared to normal hearts in all study patients. There was a statistical difference in the LVel between the survivors and non-survivors (p 0.017).
Conclusions: Despite qualitatively normal ventricular function, VVI shows significantly decreased myocardial function in both single left and right ventricles when compared to normal hearts. In the absence of traditional quantitative measures of SV function, VVI is a reliable tool to evaluate myocardial mechanics and serves as an adjunct to prognosticate clinical outcomes.
- © 2011 by American Heart Association, Inc.