Estimation of pulmonary artery pressure by ultrasound. A study comparing simultaneously recorded pulmonary valve echogram and pulmonary arterial pressures.

To determine the most reliable echocardiographic criteria of the pulmonary valve echo in predicting pulmonary artery (PA) pressures or PA resistance, 48 children, aged 6 months to 16 years with congenital (CHD) or rheumatic heart disease (RHD), were studied. During routine heart catheterization, simultaneously recorded PA pressures and one-dimensional PA valve echograms were obtained. Echocardiographic measurements of the e-f and b-c slopes, the "a" dip, right ventricular (RV) and left ventricular (LV) systolic time intervals (STI; PEP = pre-ejection period; ET = ejection time), and their ratios were compared with PA systolic, diastolic, and mean pressures as well as the pulmonary arteriolar resistance (PAR) and the ratio PAR to systemic resistance (SR). The e-f and b-c slope correlated poorly with PA pressures and PAR. RVPEP/RVET ratio gave a good second-degree polynomial correlation with PA diastolic pressure, PAR and PAR/SR in CHD (r = .78, .79, .87). The correlation was better for children with CHD than for those with RHD. This correlation was also more significant than RVPEP/LVPEP, and RVET/LVET. The "a" dip correlated well with the diastolic PA pressure in CHD and RHD (r = .73). A multivariant analysis of the "a" dip and RVSTI ratios slightly improves the correlation coefficient and the prediction rate for PA diastolic pressures, PAR, and resistance ratios in CHD and CHD + RHD.