Echocardiographic on-line quantification of left ventricular systolic function in children: a comparison with conventional off-line quantification

Accurate and efficient echocardiographic on-line determination of left vent ricular volume would be advantageous in the care of children with congenita l heart disease and children with hemodynamic instability. The prospective study was performed to evaluate the clinical usefulness of the on-line auto matic border detection system (acoustic quantification: AQ) for determinati on of left ventricular volumes and ejection fraction in comparison to the c onventional off-line method (manual tracing). 107 patients were enrolled in the study. The ages ranged from 0.1 to 18.8 y ears (mean 8.3+/-5.6). All patients were studied in the apical four-chamber plane for acoustic quantification (AQ) and manual tracing as well. Left ve ntricular volumes were determined using the mono-plane Simpson's rule. Left ventricular end-diastolic volumes obtained by AQ correlated well but w ere slightly underestimated compared to those determined by manual tracing (r=0.99). Left ventricular endsystolic volumes by AQ correlated well but we re also slighly underestimated compared to those obtained by manual tracing (r=0.98). Mean ejection fraction was 61.1+/-6.8% by AQ compared with 61.5/-5.9% by manual tracing. Linear regression analysis demonstrated good corr elation: y=0.77x+14.1, r= 0.89; p<0.001. Measurement of left ventricular volumes and ejection fraction by AQ using a utomatic border detection compares well with measurements done by manual tr acing. However, AQ tends to underestimate to some degree. The time necessar y for acquisition of data was similar in both methods. AQ seems to be a pro mising method for real-time estimation of left ventricular volume, even in children.