The impact preload on left ventricular three-plane deformation measurements in extremely premature infants

Abstract

Background: Left Ventricular (LV) deformation analysis using two-dimensional speckle tracking echocardiography (STE) is an emerging modality in premature infants. Aims: To assess the impact of increased preload on LV deformation in three planes: longitudinal, circumferential and radial in premature infants. Study design and subjects: Infants recruited to the PDA RCT (ISRCTN 13281214) and survived to discharge were included with the cohort divided into infants who closed their patent ductus arteriosus (PDA) by Day 8 (Low preload, PDA Closed) and those who maintained ductal patency (high preload, PDA Open). Outcome measures: Longitudinal, circumferential and radial strain and systolic strain rate (SRs) were measured at 36 h, Days 4 & 8 and 36 weeks. Results: 61 infants were included. The PDA open Group had a lower gestation (26.4 vs. 27.4 weeks, p < 0.01) with a median PDA exposure of 30 days (vs. 2 days, p < 0.01), and demonstrated echocardiography evidence of pulmonary overcirculation. There was higher LV longitudinal strain and SRs over the first 3 scans in the PDA Open Group. Circumferential strain was higher over the first 2 scans while circumferential SRs was higher at 36 h. Radial Strain and SRs were only higher on Day 4. Conclusion: Increased preload is associated with higher strain and systolic strain rate values in the premature population indicating that preload has a significant effect on deformation measurements in this population across all three planes.