Orla Franklin

Assessment of myocardial performance in preterm infants less than 29 weeks gestation during the transitional period.

BACKGROUND The transitional circulation and its effect on myocardial performance are poorly understood in preterm infants. AIMS We assessed myocardial performance in infants less than 29 weeks gestation in the first 48 h of life using a comprehensive echocardiographic assessment. DESIGN Infants <29 weeks gestation were prospectively enrolled. Small for gestation, infants on inotropes and/or inhaled nitric oxide and septic infants were excluded. Conventional echocardiography, left ventricular (LV), septal and right ventricular (RV) tissue Doppler imaging (TDI) and tissue Doppler-derived strain and strain rate (SR), tricuspid annular plane systolic excursion (TAPSE) and global RV fractional area change (FAC) were assessed at a median of 10 and 45 h post-delivery. RESULTS Fifty-four infants with a median [IQR] gestation and birth weight of 26.5 weeks [25.8-28.0 weeks] and 915 g [758-1142 g] were included. There was no change in shortening or ejection fraction across the two time points. Systolic and diastolic TDI of the LV, septum and RV increased across the two time points (all p values ≤ 0.01). There was an increase in septal peak systolic and early diastolic SR (p=0.002). Septal systolic strain and late diastolic SR did not change. With the exception of RV strain and early diastolic SR, all RV functional parameters including SR, late diastolic SR, TAPSE, and FAC increased across the two time points (all p values<0.01). CONCLUSION Describing the normal hemodynamic adaptations in stable preterm infants during the transitional period provides the necessary information for the assessment of those parameters in various disease states.

Cardiovascular dysfunction in infants with neonatal encephalopathy

Severe perinatal asphyxia with hypoxic ischaemic encephalopathy occurs in approximately 1–2/1000 live births and is an important cause of cerebral palsy and associated neurological disabilities in children. Multiorgan dysfunction commonly occurs as part of the asphyxial episode, with cardiovascular dysfunction occurring in up to a third of infants. This narrative paper attempts to review the literature on the importance of early recognition of cardiac dysfunction using echocardiography and biomarkers such as troponin and brain type natriuretic peptide. These tools may allow accurate assessment of cardiac dysfunction and guide therapy to improve outcome.

Novel Echocardiography Methods in the Functional Assessment of the Newborn Heart.

Echocardiography in the neonatal intensive care unit has led to improvements in our ability to assess the neonatal heart in health and disease. Advances in neonatal cardiac imaging have provided the capability to obtain quantitative information that often supersedes the qualitative information provided by conventional methods. Novel quantitative measures of function include the assessment of the velocity of muscle tissue movement during systole and diastole using tissue Doppler velocity imaging, and evaluation of deformation and rotational characteristics of the myocardium utilizing speckle tracking echocardiography or tissue Doppler-derived strain imaging. A comprehensive understanding of these novel functional modalities, their predictive value, and limitations can greatly assist in managing both the normal and maladaptive responses in the newborn period. This article discusses the novel and emerging methods for assessment of left and right heart function in the neonatal population.

The effect of milrinone on right and left ventricular function when used as a rescue therapy for term infants with pulmonary hypertension.

INTRODUCTION Milrinone may be an appropriate adjuvant therapy for infants with persistent pulmonary hypertension of the newborn. We aimed to describe the effect of milrinone administration on right and left ventricular function in infants with persistent pulmonary hypertension not responding to inhaled nitric oxide after 4 hours of administration. MATERIALS AND METHODS This is a retrospective review of infants born after or at 34 weeks of gestation with persistent pulmonary hypertension who received milrinone treatment. The primary endpoint was the effect of milrinone on myocardial performance and haemodynamics, including right and left ventricular outputs, tissue Doppler velocities, right ventricle and septal strain, and strain rate. Secondary endpoints examined included duration of inhaled nitric oxide and oxygen support. RESULTS A total of 17 infants with a mean (standard deviation) gestation and birth weight of 39.8 (2.0) weeks and 3.45 (0.39) kilograms, respectively, were included in the study. The first echocardiogram was performed 15 hours after the commencement of nitric oxide inhalation. Milrinone treatment was started at a median time of 1 hour after the echocardiogram and was associated with an increase in left ventricular output (p=0.04), right ventricular output (p=0.004), right ventricle strain (p=0.01) and strain rate (p=0.002), and left ventricle s` (p<0.001) and a` (p=0.02) waves. There was a reduction in nitric oxide dose and oxygen requirement over the subsequent 72 hours (all p<0.05). CONCLUSION The use of milrinone as an adjunct to nitric oxide is worth further exploration, with preliminary evidence suggesting an improvement in both oxygenation and myocardial performance in this group of infants.

Late medical therapy of patent ductus arteriosus using intravenous paracetamol

Objective To investigate the effect of late treatment with intravenous paracetamol on patent ductus arteriosus (PDA) closure prior to possible PDA ligation. Methods A retrospective review of infants with a haemodynamically significant PDA, considered for PDA ligation and treated with intravenous paracetamol prior to possible ligation. Results Thirty six infants with a median gestation of 26.1 weeks received paracetamol at a median age of 27 days. Paracetamol was associated with immediate closure in nine (25%) infants. There was no response to paracetamol treatment in four (11%) infants who subsequently underwent a PDA ligation. In 23 (64%) infants, the PDA constricted and all but one of this group demonstrated complete PDA closure prior to discharge. Conclusions There may be a role for intravenous paracetamol in late closure of infants with a significant PDA to avoid ligation. The use of paracetamol for late treatment of PDA should be systematically evaluated.

Treatment of premature infants with pulmonary hypertension and right ventricular dysfunction with milrinone: a case series

Objective:Milrinone has been proposed as an effective treatment for pulmonary hypertension (PH) and right ventricular (RV) dysfunction. We aimed to determine the effect of milrinone therapy on clinical and echocardiography parameters of PH in preterm infants with elevated pulmonary pressures.Study Design:A retrospective case review was conducted on infants <32 weeks gestation who received milrinone for the treatment of PH and reduced RV function. Echocardiographic data were collected before and after treatment with milrinone, and serial clinical parameters were recorded over a 72h  period.Result:Seven infants met the inclusion criteria with a median gestation and birth weight of 27.3 weeks and 1140 g, respectively. Four infants had a diagnosis of pulmonary hypoplasia with PH, and three infants were recipients in twin-to-twin transfusion syndrome who also developed PH. Nitric oxide was used in six infants before commencement of milrinone. Milrinone was commenced at a dose of 0.33 μg kg−1 min−1 to 0.5 μg kg−1 min−1 and continued for a median duration of 70 h. Use of milrinone was associated with a fall in oxygenation index and inhaled nitric oxide dose. Following an initial fall in blood pressure over the first 6 h, there was an increase in blood pressure over the subsequent 72 h. Echocardiographic data demonstrated an increase in indicators of myocardial performance and PH. One infant died before discharge.Conclusion:This case series suggests that milrinone may be a useful therapy for premature infants with echocardiography findings of PH and/or RH dysfunction. This data support the need for a randomised control trial to confirm its efficacy.

Rapid Regression of Left Ventricular Outflow Tract Rhabdomyoma After Sirolimus Therapy

The neonatal presentation of cardiac rhabdomyomas varies in severity from severe outflow tract obstruction to minimal cardiac dysfunction. The natural history for these lesions is spontaneous regression in the majority of cases. We describe a newborn boy with severe left ventricular outflow tract obstruction secondary to a large rhabdomyoma. The tumor infiltrated the paraaortic area and extended around the origin of the right coronary artery, making surgical resection challenging. Oral sirolimus therapy resulted in a rapid regression of the tumor and alleviation of outflow tract obstruction within 1 month of treatment. This is the first report of sirolimus therapy in alleviating critical left ventricular outflow tract obstruction in this condition.

Myocardial assessment using tissue doppler imaging in preterm very low-birth weight infants before and after red blood cell transfusion

Objective:To investigate myocardial velocities in anemic very low-birth weight (VLBW) preterm infants, pre and post red blood cells transfusion using tissue Doppler imaging echocardiography.Study design:Forty-eight VLBW preterm infants⩽34 weeks and>2 weeks old were prospectively divided: Transfused symptomatic infants (Hematocrit (Hct)<0.30 (n=32)) and non transfused asymptomatic controls (control 1, Hct >0.30 (n=9) and control 2, Hct <0.30 (n=7)). Echocardiography was performed before and 3–5 days after transfusion in the transfused, and the controls were studied at similar intervals. Non parametric tests were used for statistical analysis.Result:Left ventricular (LV) systolic velocity increased (transfused (4.6±0.70 vs 6.0±0.65, P<0.01)) as did LV diastolic velocities (P<0.01) without significant difference over time in each control. The percentage change in LV velocity following transfusion correlated negatively (ρ=0.36) with pre transfusion Hct.Conclusion:There is a significant increase in myocardial performance following transfusion, which is related to the severity of the anemia.

Spontaneous Closure of Patent Ductus Arteriosus in Infants ≤1500 g

Spontaneous PDA closure in VLBW infants is extremely prevalent. Infants born <26 weeks and 750 g, respectively, have a significantly higher rate of PDA at hospital discharge. OBJECTIVES: Patent ductus arteriosus (PDA) remains a challenging issue in very low birth weight (VLBW) infants, and its management varies widely. Our aim in this study was to document the natural course of ductus arteriosus in a cohort of VLBW infants who underwent conservative PDA management with no medical or surgical intervention. METHODS: A retrospective cohort study conducted in 2 European level-3 neonatal units. RESULTS: A total of 368 VLBW infants were born within the study period. Two hundred and ninety-seven infants were free of congenital malformations or heart defects and survived to hospital discharge. Out of those, 280 infants received truly conservative PDA management. In 237 (85%) of nontreated infants, the PDA closed before hospital discharge. The Kaplan-Meier model was used to document the incidence proportion of PDA closure over time for different gestational age groups. The median time to ductal closure was 71, 13, 8, and 6 days in <26+0, 26+0 to 27+6, 28+0 to 29+6, and ≥30 weeks, respectively. For different birth weight groups, the median was 48, 22, 9, and 8 days in infants weighing <750, 750 to 999, 1000 to 1249, and 1250 to 1500 g, respectively. No statistically significant relationship was found between PDA closure before hospital discharge and neonatal morbidities. CONCLUSIONS: The likelihood of PDA spontaneous closure in VLBW infants is extremely high. We provide in our findings a platform for future placebo-controlled trials focused on the smallest and youngest infants.

Maturational Patterns of Systolic Ventricular Deformation Mechanics by Two-Dimensional Speckle-Tracking Echocardiography in Preterm Infants over the First Year of Age

Background: The aim of this study was to determine the maturational changes in systolic ventricular strain mechanics by two‐dimensional speckle‐tracking echocardiography in extremely preterm neonates from birth to 1 year of age and discern the impact of common cardiopulmonary abnormalities on the deformation measures. Methods: In a prospective multicenter study of 239 extremely preterm infants (<29 weeks gestation at birth), left ventricular (LV) global longitudinal strain (GLS) and global longitudinal systolic strain rate (GLSRs), interventricular septal wall (IVS) GLS and GLSRs, right ventricular (RV) free wall longitudinal strain and strain rate, and segmental longitudinal strain in the RV free wall, LV free wall, and IVS were serially measured on days 1, 2, and 5 to 7, at 32 and 36 weeks postmenstrual age, and at 1 year corrected age (CA). Premature infants who developed bronchopulmonary dysplasia or had echocardiographic findings of pulmonary hypertension were analyzed separately. Results: In uncomplicated preterm infants (n = 103 [48%]), LV GLS and GLSRs remained unchanged from days 5 to 7 to 1 year CA (P = .60 and P = .59). RV free wall longitudinal strain, RV free wall longitudinal strain rate, and IVS GLS and GLSRs significantly increased over the same time period (P < .01 for all measures). A significant base‐to‐apex (highest to lowest) segmental longitudinal strain gradient (P < .01) was seen in the RV free wall and a reverse apex‐to‐base gradient (P < .01) in the LV free wall. In infants with bronchopulmonary dysplasia and/or pulmonary hypertension (n = 119 [51%]), RV free wall longitudinal strain and IVS GLS were significantly lower (P < .01), LV GLS and GLSRs were similar (P = .56), and IVS segmental longitudinal strain persisted as an RV‐dominant base‐to‐apex gradient from 32 weeks postmenstrual age to 1 year CA. Conclusions: This study tracks the maturational patterns of global and regional deformation by two‐dimensional speckle‐tracking echocardiography in extremely preterm infants from birth to 1 year CA. The maturational patterns are ventricular specific. Bronchopulmonary dysplasia and pulmonary hypertension leave a negative impact on RV and IVS strain, while LV strain remains stable. HighlightsTwo‐dimensional (2D) speckle‐tracking echocardiography (STE)–derived myocardial strain is a feasible and reproducible imaging modality that can be used to characterize systolic ventricular function in premature infants.This study establishes ventricular‐specific systolic strain maturational patterns by 2D STE in a large cohort of extremely preterm infants from birth through 1 year corrected age.Common cardiopulmonary morbidities, such as bronchopulmonary dysplasia and pulmonary hypertension, appear to leave a negative impact on right ventricular strain, while left ventricular strain remains stable through the first year of age.With the establishment of the range of maturational patterns of strain mechanics and associated variations up to 1 year corrected age, deformation imaging by 2D STE may now be implemented in preterm infants as a means to identify cardiovascular compromise earlier, guide therapeutic intervention, monitor treatment response, and improve overall outcome.