Abstract 10413: A Comparison of Single Morphological Right and Left Ventricular Function Using Speckle Tracking Imaging
Background: Myocardial dysfunction is an important risk factor for morbidity and mortality in single ventricle patients. A single right ventricle (SRV) may confer additional risk. There are a paucity of reports comparing the mechanics of ventricular function between SRV and single left ventricles (SLV). Our aim was to determine the differences between SRV and SLV function using speckle tracking imaging.
Methods: A prospective, cross-sectional study comparing 21SRV and 21SLV matched for age and the stage of surgical palliation, 7 pre-Glenn, 7 pre-Fontan, 7 post-Fontan patients per group. We measured longitudinal, circumferential strain, systolic strain rate (SR) and diastolic SR (un-SR). Post systolic strain index (PSSi) was calculated as a percentage of post-systolic strain divided by peak strain, and myocardial dyssynchrony index (MDI) as the standard deviation of segmental time to peak strain (% systole). SRV and SLV were compared using Wilcoxon rank sum test (p < 0.05).
Results: SRV had reduced circumferential SR (−1.1%/s vs. −1.5%/s, p=0.013) and longitudinal SR (−0.9%/s vs. −1.3%/s, p=0.003) as well as reduced circumferential un-SR (1.3%/s vs. 1.8%/s, p=0.04). SRV PSSi was increased in both circumferential (8% vs. 0%, p=0.0003) and longitudinal (2% vs. 0%, p=0.03) planes. The SRV also showed increased longitudinal MDI (15% vs. 12%, p=0.04). No difference in strain was found between SRV and SLV. Sub-analysis at each stage showed that the differences occurred at the pre-Glenn stage (longitudinal SR, p=0.02; PSSi, p=0.03) and regained parity post-Fontan.
Conclusions: SRV displayed impaired contractility and diastolic dysfunction when compared to SLV. The mechanisms for SRV dysfunction may be related to the presence of increased mechanical dyssynchrony and PSSi, a potential marker of ischemia. The SRV may have poorer adaptation to loading conditions between staged palliations compared to a SLV.
- © 2010 by American Heart Association, Inc.