Quantitative echocardiographic assessment of the performance of the functionally single right ventricle after the Fontan operation

Background: Performance of the functionally single right ventricle may dete riorate over time. Quantitative assessment of this chamber, however, is com plicated by its asymmetric geometry. Automatic detection of borders, and th e Doppler-derived index of myocardial performance, are echocardiographic te chniques that allow for quantitative assessment regardless of ventricular s hape. We sought eo evaluate the mechanics of contraction and relaxation in the functionally single right ventricle using these parameters. Methods: We evaluated systemic ventricular function in 35 asymptomatic patients with f unctionally single right ventricle, having a mean age of 7.8 +/- 3.1 years, who had undergone the Fontan procedure. We compared them with 32 age-match ed normal controls using both automatic detection of borders and Doppler in dexes. Results: When compared with the controls, the group with a functiona lly single right ventricle demonstrated diminished systolic function as evi denced by a lower fractional change in area (42.7 +/- 10.1% vs. 54.6 +/- 10 .5%, p = 0.001), and diminished diastolic function, as demonstrated by a gr eater reliance on aerial contraction to achieve ventricular filling (32.0 /- 4.4% vs. 22.2 +/- 4.1%, p = 0.001). The mean index of myocardial perform ance in those with functionally single right ventricles was also greater th an in controls (0.41 +/- 0.12 vs. 0.30 +/- 0.05, p = 0.001), and the indexe d ejection time was shorter (0.35 +/- 0.05 vs. 0.39 +/- 0.05, p = 0.01), su ggesting less efficient ventricular mechanics. Conclusions: These data demo nstrate that the systolic and diastolic properties of the functionally sing le right ventricle differ significantly from those of the normal systemic l eft ventricle. Use of the echocardiographic techniques provide insight into ventricular mechanics in patients with functionally single ventricles, and may be valuable tools for serial quantitative follow-up.