Accuracy of the Doppler-derived pressure gradient in pediatric patients with aortic valvular stenosis: is the correction for pressure recovery necessary?

The Doppler echocardiography derived peak instantaneous systolic pressure gradient (peak instantaneous Doppler PG), the mean PG (mean Doppler PG) and the aortic valvular area are the accepted standard for determining the prognosis and optimal timing of intervention because of good agreement between Doppler-derived and catheter-measured PGs in adult patients with aortic valvular stenosis. However, several investigators reported that pressure recovery can cause discrepancies between Doppler-derived and catheter-measured PGs, so that the correction for pressure recovery has been proposed. In pediatric patients with aortic valvular stenosis, the discrepancy between Doppler-derived and catheter-measured PGs and the correction for pressure recovery have not been studied well. Therefore, the purpose of current study was to clarify the role of echocardiography for estimating the prognosis and optimal timing of intervention and to assess the influence of pressure recovery on the Doppler-derived PG in pediatric patients with aortic valvular stenosis. Thirteen pediatric patients with aortic valvular stenosis were studied with echocardiography and cardiac catheterization. PG determined by the catheterization was compared with PG determined by the echocardiography with linear regression and Bland and Altman analysis. As result, Doppler-derived PGs corrected for pressure recovery did not correlated well with catheter-measured PGs. By contrast, Doppler-derived PGs correlated well with catheter-measured PGs. In particular, the mean Doppler PG correlated excellently with the mean catheter PG. In conclusion, the mean Doppler PG demonstrated an excellent correlation with the mean catheter PG without the correction for pressure recovery. Thus, the mean Doppler PG is useful in order to determine the prognosis and optimal timing of intervention in pediatric patients with aortic valvular stenosis.