The Measurement of Neonatal Pulmonary Artery Pressure by Echocardiography

ABSTRACT

PURPOSE: The main purpose of this study was to conduct accurate noninvasive measurement of the pulmonary artery pressure(PAP) in the neonatal period. The other purpose was to find some descriminant factors that are correlated with pulmonary artery pressure even when there is no tricuspid regurgitation(TR) or patent ductus arteriosus(PDA). METHODS: 32 cases of premature and full term infants with definite tricuspid regurgitation were examined by echocardiography. Correlations between PAP and factors such as peak flow velocity of TR, peak flow velocity of PDA, ventricular septal curvature ratio, ratio between pulmonary artery diameter at systole and diastole, systolic time interval(STI), and ratio between right ventricular acceleration time and ejection time(RVAT/ET) were analyzed. RESULTS: There was a significant correlation between the PAP detected by the peak velocity of TR and the PAP calculated by the transductal pressure gradient(r2=0.70, P<0.01). PAP measured by the peak flow velocity of TR and factors such as ventricular septal curvature ratio, the ratio of the pulmonary artery diameter at systole and diastole, STI, and RVAT/ET had no significant correlation. STI was higher when there was PDA(P<0.01) and the acceleration time was also significantly increased in those cases(P<0.01). The ratio of the PAD at systole and diastole was higher with PDA(P<0.01). In cases with PDA, STI has negative correlation with the transductal pressure gradient(P<0.01). CONCLUSION: Measuring PAP in the neonatal period by echocardiography is a relatively accurate noninvasive method. The PAP was influenced by several factors during the measurement. Those factors were the patency itself of the ductus arteriosus and the transductal pressure gradient.