Echocardiographic correlates of persistent pulmonary hypertension of the newborn.

AIMS: To compare echocardiographic (ECHO) measures of ventricular function and hemodynamics of infants with persistent pulmonary hypertension of the newborn (PPHN) and normal controls; and to examine their association with clinical outcomes in PPHN.

DESIGN/SUBJECTS: We performed a retrospective review of ECHOs of mechanically ventilated infants (≥ 34 weeks gestational age) with PPHN. Infants with congenital heart disease were excluded. Controls had normal ECHOs within 1 week of age.

OUTCOMES: ECHOs measures included a) right (RVO) and left ventricular output (LVO) b) RV and LV myocardial performance index (MPI) c) right ventricular systolic to diastolic duration (S/D) ratio and d) eccentricity index in systole (EIs) and diastole (EId).

RESULTS

Infants with PPHN (n = 117), 63% of whom were males, had mean (SD) GA and birth weights of 38.6 (1.9) weeks and 3.3 (0.65) kg respectively. LVO, RVO and EIs were significantly lower and heart rate, MPI and RV S/D ratio were significantly higher in infants with PPHN, compared to controls (n = 35). The mean RV S/D ratios were significantly higher in infants with PPHN who died or required ECMO (n = 61), compared to survivors without ECMO (n = 56). Increasing RV S/D ratio was independently associated with a reduction in survival without ECMO [0.21; 95% C.I. 0.06-0.74, p = 0.015]. RV S/D ratio >1.3 had a sensitivity of 93 (95% C.I. 85-99) % for death or ECMO.

CONCLUSIONS

Elevated RV S/D ratio, a marker of global RV dysfunction, was associated with adverse outcomes in PPHN. Its routine measurement in this population may aid risk-identification and targeted interventions.