Evaluation of ventricular filling pressures and ventricular function by Doppler echocardiography in patients with functional single ventricle: correlation with simultaneous cardiac catheterization.

BACKGROUND

Elevated ventricular filling pressure is a marker of diastolic dysfunction and a known risk factor for failure of single-ventricle surgical palliation. Doppler echocardiography has been shown valuable in identifying patients with elevated ventricular end-diastolic pressure (VEDP) in other settings, but its utility in evaluating pediatric patients with single ventricle is unclear. The aim of this study was to compare Doppler parameters to simultaneous catheter measurements of VEDP in children with single ventricle.

METHODS

All consecutive patients (age < 18 years) with single ventricle who underwent simultaneous echocardiography and catheterization in 2009 and 2010 were included in this prospective study. Data regarding diagnosis, morphology of the "single" ventricle, prior surgeries, Doppler tissue imaging (DTI), atrioventricular valve inflow and pulmonary vein Doppler, and myocardial performance index (MPI) were collected. Ventricular Doppler echocardiography was performed from the dominant ventricle. Simultaneous Doppler and catheter measurements of systolic and diastolic function and VEDP were obtained. Correlation of continuous variables was examined using linear regression analysis. Receiver operating characteristic curves, two-sample Student's t tests, χ(2) analyses, and Fisher's exact tests were used as appropriate.

RESULTS

A total of 32 patients (15 male; mean age, 30.2 ± 22 months) were studied (nine post-Fontan, 15 post-Glenn, and eight pre-Glenn). Mean systemic arterial saturation was 81 ± 10%, mean VEDP was 11 ± 3 mm Hg, and mean echocardiographically estimated ejection fraction was 55 ± 7%. VEDP was correlated positively with E/E' ratio (r = 0.44, P < .01), pulmonary vein atrial reversal duration (r = 0.77, P < .001), and E' (r = 0.49, P < .01). Receiver operating characteristic curve analysis using an E/E' cutoff of 12 showed sensitivity of 90% (95% confidence interval, 54.1%-99.5%) and specificity of 75.0% (95% confidence interval, 47.4%-91.7%) for identifying VEDP > 10 mm Hg. Single left ventricles had higher DTI S' and E' velocities and lower E/E' ratios and MPIs compared with single right ventricles. S' velocity correlated positively with ejection fraction (r = 0.77, P < .001) and negatively with single left ventricular MPI (r = -0.46, P < .01).

CONCLUSIONS

In patients with single-ventricle physiology, DTI and pulmonary vein Doppler echocardiographic parameters correlated modestly with direct measurement of VEDP and may be helpful in identifying patients with elevated filling pressures. In addition, single left ventricles had better systolic and diastolic performance than single right ventricles. DTI systolic velocities and left ventricular MPI correlated well with ventricular ejection fraction.