Longitudinal systolic strain of the bilayered ventricular septum during the first 72 hours of life in preterm infants.

Abstract

Quantitative evaluation of right ventricular myocardial performance in preterm infants remains a challenge because of the limitations of conventional echocardiographic measurement and the complex geometry of the right ventricle (RV). Serial assessment of peak longitudinal systolic strain on the right and left sides of the ventricular septum (VS), RV, and left ventricle (LV) during the transitional period in preterm infants using two-dimensional speckle-tracking echocardiography is reported. In 21 preterm infants (33±2 gestational weeks, 1,913 ± 218 g birth weight) without mechanical ventilation, inotropic agents, or symptomatic patent ductus arteriosus (PDA), longitudinal strain (LS) was measured on both sides of the VS, RV free wall, and LV, along with conventional echocardiography at 1, 3, 6, 9, 12, 24, 48, and 72 h after birth. Correlations and factors associated with echocardiographic measurements were analyzed. LS was maintained on the four analyzed regions during the first 72h of life despite significant hemodynamic changes, including a decrease in pulmonary artery pressure and PDA closure. LS was significantly larger on the left side of the VS than on the right side of the VS at 1, 48, and 72h after birth. Preterm infants showed stable LS on both sides of the VS, the RV free wall, and the LV despite significant hemodynamic changes during the first 72h of life. These results suggest that the right and left sides of the VS respond differently to the complex cardiopulmonary transitions from fetal to neonatal life in preterm infants.