OBJECTIVETo evaluate the relationship of right ventricular function with the indexes of blood gas in neonates with hypoxic pulmonary hypertension (HPH).

METHODSSixty-seven neonates with HPH (29 mild, 23 moderate and 15 severe) and 22 gestational age- and weight-matched neonates without HPH (control group) were enrolled. On postnatal days 1, 3 and 7, pulmonary artery systolic pressure (PASP) was measured by pulsed Doppler echocardiography. Systolic wave of ventricular (Sa), early diastolic wave (Ea), late diastolic wave (Aa), and Ea/Aa ratio were determined by the tissue Doppler imaging (TDI) technology. Artery oxygen pressure (PaO(2)), fractional concentration of inspired oxygen (FiO(2)), and PaO(2)/ FiO(2) ratio were simultaneously observed.

RESULTSOn postnatal day 1, PaO(2) and PaO(2)/FiO(2) ratio as well as Ea and Ea/Aa ratio were significantly lower, while PASP was significantly higher in the HPH groups than those in the control group. Sa decreased in the moderate and severe HPH groups, Aa increased in the moderate HPH group, and Aa decreased significantly in the severe HPH group compared with that in the control group. On postnatal day 3, PaO(2) and PaO(2)/FiO(2) ratio returned to normal level in the mild and moderate HPH groups, while other indexes remained abnormal. On postnatal day 7, all the indexes above returned to normal level in the mild HPH group; Ea and Ea/Aa ratio were still significantly lower in the moderate HPH group, and the other indexes returned to normal level; in the severe HPH group, only PaO(2) and PaO(2)/FiO(2) ratio returned to normal level.

CONCLUSIONSThe changes and recovery of diastolic and systolic functions of right ventricular are not paralleled with hypoxia and PASP in neonates with HPH. It is helpful for the diagnosis and treatment of HPH by monitoring PASP and right ventricular function with TDI.