Abstract 11298: Three-Dimensional Mechanical Dyssynchrony and Myocardial Deformation of the Left Ventricle in Patients with Tricuspid Atresia after Fontan Procedure
Introduction: Ventricular dysfunction remains an important long-term complications in patients with functionally univentricular hearts palliated by Fontan procedures. Data on the mechanics of the systemic ventricle in these patients are, however, limited.
Hypothesis: This study tested the hypothesis that dyssynchronous contraction of functional single ventricles occurs in Fontan patients and is related to indices of myocardial deformation and global ventricular function.
Methods: This cross-sectional study was conducted in a tertiary paediatric cardiac centre. Twenty patients with tricuspid atresia, aged 23.5±7.1 years, were studied at 17.8±3.8 years after Fontan procedure. Three-dimensional echocardiographic data were acquired for determination of left ventricular (LV) volumes and systolic dyssynchrony index (SDI). Left ventricular myocardial deformation were determined using speckle tracking echocardiography. Calibrated integrated backscatter (cIB) intensity was measured as an index of myocardial fibrosis. The results were compared with those of 20 controls.
Results: Compared with controls, patients had significantly greater SDI (6.13%±1.32% vs 4.06%±0.84%, p<0.001). The prevalence of LV mechanical dyssynchrony (SDI >5.74%) in patients was 55% (95% CI, 32% to 77%). The LV global systolic longitudinal, radial and circumferential strain (all p<0.001), longitudinal systolic (p<0.001) and early diastolic strain rate (p<0.001), and circumferential systolic (p<0.001) and early diastolic strain rate (p=0.009) were significantly lower in patients than controls, while the average cIB was higher (p<0.001). Patients with LV dyssynchrony (n=11) had lower global LV longitudinal strain (p=0.02), reduced LV ejection fraction (p=0.002), and higher average cIB (p=0.03) than those without (n=9).
Conclusions: A high proportion of patients with tricuspid atresia after Fontan operation exhibits LV mechanical dyssynchrony, which may in part be related to myocardial fibrosis and has implications on myocardial deformation and global ventricular function.
- © 2011 by American Heart Association, Inc.