Myocardial function in late preterm infants during the transitional period: comprehensive appraisal with deformation mechanics and non-invasive cardiac output monitoring.

BACKGROUND: There is a paucity of functional data on mid-to-late preterm infants between 30+0 and 34+6 weeks gestation. We aimed to characterise transitional cardiopulmonary and haemodynamic changes during the first 48 hours in asymptomatic mid-to-late preterm infants. METHODS: Forty-five healthy preterm newborns (mean ± standard deviation) gestation of 32.7 ± 1.2 weeks) underwent echocardiography on Days 1 and 2. Ventricular mechanics were assessed by speckle tracking-derived deformation, rotational mechanics, tissue Doppler imaging, and right ventricle-focused measures (tricuspid annular plane systolic excursion, fractional area change). Continuous haemodynamics were assessed using the NICOM™ system to obtain left ventricular output, stroke volume, heart rate, and total peripheral resistance by non-invasive cardiac output monitoring. RESULTS: Right ventricular function increased (all measures p < 0.005) with mostly stable left ventricular performance between Day 1 and Day 2. NICOM-derived left ventricular output [mean 34%, 95% confidence interval 21-47%] and stroke volume [29%, 16-42%] increased with no change in heart rate [5%, -2 to 12%]. There was a rise in mean blood pressure [11%, 1-21%], but a decline in total peripheral resistance [-14%, -25 to -3%]. CONCLUSION: Left ventricular mechanics remained persevered in mid-to-late premature infants, but right ventricular function increased. Non-invasive cardiac output monitoring is feasible in preterm infants with an increase in left ventricular output driven by an improvement in stroke volume during the transitional period.

Circumferential and radial deformation assessment in premature infants: Ready for primetime?

BACKGROUND: Speckle tracking echocardiography (STE) is a validated method to measure longitudinal deformation in premature infants, but there is a paucity of data on STE-derived circumferential and radial strain in this population. We assessed the feasibility and reproducibility of circumferential and radial deformation measurements in premature infants. METHODS: In a prospective study of 40 premature infants (<29 weeks of gestation at birth), STE-derived circumferential and radial strain, systolic strain rate (SRs), early diastolic strain rate (SRe), and late diastolic strain rate (SRa) were measured on day 2 and day 8. Intra- and inter-observer reproducibility analysis were performed using Bland-Altman analysis, coefficient of variation (COV), and intra-class correlation coefficient (ICC). The impact of a persistent patent ductus arteriosus (PDA) was analyzed. RESULTS: Deformation analysis was feasible in 98% of the acquisitions. Circumferential parameters demonstrated excellent intra- and inter-observer reproducibility with an ICC between 0.89 and 0.99 (all P < 0.001) and a COV between 4% and 13%. Radial parameters demonstrated acceptable intra- and inter-observer reproducibility with an ICC between 0.73 and 0.96 (all P < 0.001) and a COV between 14% and 27%. Infants with a PDA on day 8 (n = 21, 53%) demonstrated higher radial strain, SRs and SRe. There were no differences in circumferential parameters with a PDA at either time point. CONCLUSION: This study demonstrates clinical feasibility and reproducibility of circumferential and radial strain by STE in premature infants. A PDA elevates radial deformation measures, suggesting that the increased LV preload from a PDA may augment intrinsic contractility in the radial but not circumferential plane.

Postnatal Myocardial Function in Monochorionic Diamniotic Twins with Twin-to-Twin Transfusion Syndrome following Selective Laser Photocoagulation of the Communicating Placental Vessels.

BACKGROUND: Monochorionic diamniotic (MCDA) twins are at risk for developing twin-to-twin transfusion syndrome (TTTS) throughout pregnancy. This may lead to myocardial dysfunction in the recipient and/or donor twin that persists beyond delivery. Selective laser photocoagulation of the communicating placental vessels (SLPCV) attempts to mitigate the cardiovascular outcomes. The objective of this study was to characterize early postnatal myocardial performance in MCDA twins with TTTS with and without SLPCV. METHODS: A prospective study was performed of four MCDA twin groups: (1) uncomplicated MCDA twins, (2) MCDA twins with selective fetal growth restriction, (3) MCDA twins with TTTS following SLPCV (TTTS with SLPCV), and (4) MCDA twins with TTTS who did not undergo SLPCV (TTTS without SLPCV). Fifty-four twin pairs were enrolled: 23 uncomplicated MCDA twin pairs, 15 pairs with selective fetal growth restriction, seven TTTS pairs with SLPCV, and seven TTTS pairs without SLPCV. In each group, twin pairs were divided by birth weight into donor (smaller) and recipient (larger) and compared. Echocardiography was performed on day 1, day 2, and between days 5 and 7 of age, and myocardial performance was characterized by speckle-tracking echocardiography-derived left ventricular and right ventricular longitudinal strain (LS) and systolic strain rate (LSR). Longitudinal strain and longitudinal systolic strain rate are expressed as absolute values. RESULTS: Compared with all recipient groups, recipient TTTS without SLPCV infants had lower left ventricular LS (16 ± 3% vs 22%-24%, P < .01) and right ventricular LS (15 ± 5% vs 21%-24%, P < .01) on day 1 that persisted throughout the first week of age. Left ventricular LSR (1.7 ± 0.3 vs 2.3 ± 0.3 sec-1, P < .05) and right ventricular LSR (1.5 ± 0.4 vs 1.7 ± 0.5 sec-1, P < .05) were both lower in the recipient compared with the donor twin in the TTTS without SLPCV group. LS and LSR measurements were similar among all four donor twin groups. CONCLUSIONS: Biventricular performance is diminished in recipient MCDA twins with TTTS who are not treated with SLPCV, highlighting the need for close monitoring of their hemodynamic status during the early neonatal period.

Infants Born with Down Syndrome: Burden of Disease in the Early Neonatal Period.

OBJECTIVE: To evaluate the incidence of direct admission of infants with Down syndrome to the postnatal ward (well newborn nursery) vs the neonatal intensive care unit (NICU), and to describe the incidence of congenital heart disease (CHD) and pulmonary hypertension (PH). STUDY DESIGN: This retrospective cohort study of Down syndrome used the maternal/infant database (2011-2016) at the Rotunda Hospital in Dublin, Ireland. Admission location, early neonatal morbidities, outcomes, and duration of stay were evaluated and regression analyses were conducted to identify risk factors associated with morbidity and mortality. RESULTS: Of the 121 infants with Down syndrome, 54 (45%) were initially admitted to the postnatal ward, but 38 (70%) were later admitted to the NICU. Low oxygen saturation profile was the most common cause for the initial and subsequent admission to the NICU. Sixty-six percent of the infants (80/121) had CHD, 34% (41/121) had PH, and 6% died. Risk factors independently associated with primary NICU admission included antenatal diagnosis of Down syndrome, presence of CHD, PH, and the need for ventilation. CONCLUSIONS: Infants with Down syndrome initially admitted to the postnatal ward have a high likelihood of requiring NICU admission. Overall, high rates of neonatal morbidity were noted, including rates of PH that were higher than previously reported. Proper screening of all infants with Down syndrome for CHD and PH is recommended to facilitate timely diagnoses and potentially shorten the duration of the hospital stay.