Serial Assessment of Cardiac Function and Pulmonary Hemodynamics in Infants With Down Syndrome.

BACKGROUND: There is a dearth of longitudinal data describing the evolution of cardiopulmonary hemodynamics in infants with Down syndrome (DS) beyond infancy. We hypothesized that babies with DS, independent of the presence of congenital heart disease (CHD), demonstrate biventricular systolic and diastolic impairment and sustained elevation of pulmonary pressures compared with controls over the first 2 years of age. METHODS: This was a prospective observational cohort study of 70 infants with DS (48 with CHD and 22 without CHD) and 60 controls carried out in 3 tertiary neonatal intensive care units in Dublin, Ireland. Infants with DS with and without CHD and non-DS controls underwent serial echocardiograms at birth, 6 months, 1 year, and 2 years of age to assess biventricular systolic and diastolic function using deformation analysis. Pulmonary vascular resistance was assessed using pulmonary artery acceleration time and left ventricular (LV) eccentricity index. RESULTS: Infants with DS exhibited smaller LV (birth: 27 ± 4 vs 31 ± 2 mm, P < .01; 2 years: 43 ± 5 vs 48 ± 4 mm, P < .01) and right ventricular (birth: 28 ± 3 vs 31 ± 2 mm, P < .01; 2 years: 40 ± 4 vs 44 ± 3 mm, P < .01) lengths and lower LV (birth: -19% ± 3% vs -22% ± 2%, P < .01; 2 years: -24% ± 2% vs -26% ± 2%, P < .01) and right ventricular (birth: -19% ± 4% vs -22% ± 3%, P < .01; 2 years: -29% ± 6% vs -33% ± 4%, P < .01) systolic strain over the 2-year period. Pulmonary artery acceleration time was lower in the DS group throughout the study period (birth: 44 ± 10 vs 62 ± 14 ms, P < .01; 2 years 71 ± 12 vs 83 ± 11 ms, P < .01). No differences were observed between DS infants with and without CHD (all P > .05). CONCLUSIONS: Infants with DS exhibit impaired maturational changes in myocardial function and pulmonary vascular resistance. Such novel findings provide valuable insights into the pathophysiology affecting cardiorespiratory morbidity in this population.

Longitudinal assessment of cardiac function in infants with Down's syndrome using novel echocardiography techniques - project protocol.

Background: Down's syndrome (DS) is the most common chromosomal abnormality globally. Ireland has one of the highest rates of DS in the western world with an incidence of 1:444 live births. Congenital heart disease (CHD) and pulmonary hypertension (PH) are the commonest morbidities affecting the cardiovascular system in DS. PH is associated with significant morbidity and an increase risk of mortality. The impact of the diagnosis of DS, the presence of CHD and the associated PH on myocardial function during transition and over the first 2 years of age in this population is not well defined and warrants further study. In particular, serial measurements of pulmonary pressures in this population over the first week of age are lacking. This study aims to characterise myocardial function and pulmonary haemodynamics in infants with Down syndrome during the transitional period (over the first week of age) and throughout the first two years of age. Methods: A prospective, observational study utilising novel echocardiography techniques to assess myocardial function and pulmonary haemodynamics over the first two years of age in infants with Down Syndrome. A population of healthy infants without CHD or a diagnosis of DS will be recruited as controls. This study will be conducted across the three Dublin maternity units. Discussion: In total, 70 babies with DS have been enrolled into this study with 292 echocardiograms performed to date. Further evaluation of cardiac performance in DS infants with and without CHD may yield more insight into the pathophysiology of cardiac dysfunction and pulmonary hypertension that are recognised features in these patients. This could aid in our ability to monitor and treat patients, as well as improve our ability to predict outcomes.

Noninvasive continuous cardiac output and cerebral perfusion monitoring in term infants with neonatal encephalopathy: assessment of feasibility and reliability.

BackgroundNoninvasive hemodynamic monitoring of infants with neonatal encephalopathy (NE) undergoing therapeutic hypothermia (TH) would be a potentially useful clinical tool. We aimed to assess the feasibility and reliability of noninvasive cardiac output monitoring (NICOM) and near-infrared spectroscopy (NIRS) in this cohort.MethodsNICOM and NIRS were commenced to measure cardiac output (CO), systemic vascular resistance (SVR), blood pressure (BP), and cerebral regional oxygen saturations (SctO2) during TH and rewarming. NICOM measures of CO were also compared with simultaneous echocardiography-derived CO (echo-CO).ResultsTwenty infants with a median gestation of 40 weeks were enrolled. There was a strong correlation between NICOM- and echo-CO (r2=0.79, P<0.001). NICOM-CO was systematically lower than echo-CO with a bias of 27% (limits of agreement 3-51%). NICOM illustrated lower CO during TH, which increased during rewarming. SctO2 increased over the first 30 h of TH and stayed high for the remainder of the study. There was a rise in SVR over the first 30 h of TH and a decrease during rewarming (all P<0.05).ConclusionsNoninvasive hemodynamic assessment of infants with NE is feasible and illustrates potentially important changes. Larger studies are needed to assess the clinical applicability of those methods in this cohort.

Is routine transvaginal cervical length measurement cost-effective in a population where the risk of spontaneous preterm birth is low?

INTRODUCTION: A recent meta-analysis has suggested that routine measurement of the cervical length should be performed in conjunction with the anomaly scan to identify a group of women at increased risk of preterm delivery. We decided to investigate whether this recommendation is justifiable in a population where the risk of preterm birth is low. MATERIAL AND METHODS: We reviewed 12 years of obstetric data from the Coombe Women and Infants University Hospital. Relative risks of adverse outcomes from the randomized controlled trial were applied and we extrapolated the possible numbers of women requiring intervention. We then used published neonatal data to estimate the cost of neonatal care and estimated the costs of providing the service. RESULTS: Over 12 years from 2000 until 2011, there were 94 646 singleton deliveries, 1776 happening before 34 weeks. Spontaneous onset occurred in 882 (49.7%) of this group. These 882 births were studied. If we apply the figures from a randomized controlled trial, 1609 women (1.7% from our total population) would be expected to have a cervical length 15 mm. If we gave vaginal progesterone to all women with a sonographically short cervix, we would reduce the delivery rate before 34 weeks by 27.7%. The annual costs of providing the service were estimated to be €109 249 and the cost of immediate neonatal care was estimated to be €380 514. CONCLUSION: Given the implications associated with preterm delivery, routine measurement of cervical length at the time of the anomaly scan may be justifiable from a cost point of view in a population where the risk of preterm birth is low.