Right Ventricular Global Longitudinal Strain in Fetuses with Hypoplastic Left Heart Syndrome Does Not Differ Between Those With and Without Genetic Conditions.

The presence of a genetic condition is a risk factor for increased mortality in hypoplastic left heart syndrome (HLHS). Speckle tracking strain analysis in interstage echocardiograms have shown promise in identifying patients with HLHS at increased risk of mortality. We hypothesized that fetuses with a genetic condition and HLHS have impaired right ventricular global longitudinal strain compared with fetuses with HLHS and no evident genetic condition. We performed a retrospective analysis of 60 patients diagnosed in fetal life with HLHS from 11/2015 to 11/2019. We evaluated presenting echocardiograms and calculated right ventricular global longitudinal strain (RV GLS) and fractional area of change (FAC) using post-processing software. We first compared RV GLS and FAC between those with genetic conditions to those without. We examined the secondary outcome of mortality among those with and without genetic conditions and among HLHS subgroups. Of the 60 patients with available genetic testing, 11 (18%) had an identified genetic condition. Neither RV GLS nor FAC was significantly different between patients with and without genetic conditions. There was no difference in RV GLS or FAC among HLHS phenotype or those who died or survived as infants. However, patients with a genetic syndrome had increased neonatal and overall mortality. In this cohort, RV GLS did not differ between those with and without a genetic diagnosis, among HLHS phenotypes, or between those surviving and dying as infants. Further analysis of strain throughout gestation and after birth could provide insight into the developing heart in fetuses with HLHS.

Paediatrician's guide to post-operative care for functionally univentricular CHD: a review.

IMPORTANCE: Single ventricle CHD affects about 5 out of 100,000 newborns, resulting in complex anatomy often requiring multiple, staged palliative surgeries. Paediatricians are an essential part of the team that cares for children with single ventricle CHD. These patients often encounter their paediatrician first when a complication arises, so it is critical to ensure the paediatrician is knowledgeable of these issues to provide optimal care. OBSERVATIONS: We reviewed the subtypes of single ventricle heart disease and the various palliative surgeries these patients undergo. We then searched the literature to detail the general paediatrician's approach to single ventricle patients at different stages of surgical palliation. CONCLUSIONS AND RELEVANCE: Single ventricle patients undergo staged palliation that drastically changes physiology after each intervention. Coordinated care between their paediatrician and cardiologist is requisite to provide excellent care. This review highlights what to expect when these patients are seen by their paediatrician for either well child visits or additional visits for parental or patient concern.

Paediatrician's guide to post-operative care for biventricular CHD: a review.

IMPORTANCE: Paediatricians play an integral role in the lifelong care of children with CHD, many of whom will undergo cardiac surgery. There is a paucity of literature for the paediatrician regarding the post-operative care of such patients. OBSERVATIONS: The aim of this manuscript is to summarise essential principles and pertinent lesion-specific context for the care of patients who have undergone surgery or intervention resulting in a biventricular circulation. CONCLUSIONS AND RELEVANCE: Familiarity with common issues following cardiac surgery or intervention, as well as key details regarding specific lesions and surgeries, will aid the paediatrician in providing optimal care for these patients.

Umbilical Artery Doppler Patterns and Right Ventricular Outflow Abnormalities in Twin-Twin Transfusion Syndrome.

OBJECTIVES: To evaluate the association of abnormal Doppler velocimetric patterns in the umbilical arteries (UAs) and right ventricular outflow tract abnormalities (RVOTAs) in twin- twin transfusion syndrome (TTTS) cases. METHODS: This retrospective study involved women who had laser surgery for TTTS between January 2012 and May 2018 at a single institution. The prevalence of an RVOTA in either twin was compared among TTTS cases in which both twins had positive end-diastolic flow (EDF) in the UA and those in which either twin had intermittent or persistent absent/reversed UA EDF. Nonparametric tests were used for comparisons. Logistic regression was performed to identify variables associated with an RVOTA in either twin, adjusted for moderate or severe tricuspid regurgitation, right ventricular hypertrophy, right ventricular systolic or diastolic dysfunction, the Quintero stage, and other confounders. P < .05 was considered significant. RESULTS: A total of 126 consecutive TTTS cases were included. Right ventricular outflow tract abnormalities were seen in 8.7% (11of 126) of cases, all in recipient twins. Significant differences in the rate of RVOTAs in the recipient twin were seen between TTTS cases with intermittent absent/reversed UA EDF and those with positive UA EDF (26.9% [7 of 26] versus 3.7% [3 of 82]; P = .002]. However, no significant differences were noted among the other study groups. Intermittent absent/reversed UA EDF was associated with a significantly increased risk for an RVOTA (adjusted odds ratio, 20.6 [95% confidence interval, 3.1-138]; P = .002) after adjusting for confounders. CONCLUSIONS: Intermittent changes in vascular impedance to UA flow may contribute to the pathogenesis of acquired right-sided cardiac lesions in the recipient twin affected with TTTS.

Adaptations of paediatric cardiology practice during the COVID-19 pandemic.

During the initial surge of the COVID-19 pandemic in the spring and summer of 2020, paediatric heart centres were forced to rapidly alter the way patient care was provided to minimise interruption to patient care as well as exposure to the virus. In this survey-based descriptive study, we characterise changes that occurred within paediatric cardiology practices across the United States and described provider experience and attitudes towards these changes during the pandemic. Common changes that were implemented included decreased numbers of procedures, limiting visitors and shifting towards telemedicine encounters. The information obtained from this survey may be useful in guiding and standardising responses to future public health crises.

Chronic Maternal Hyperoxygenation and Effect on Cerebral and Placental Vasoregulation and Neurodevelopment in Fetuses with Left Heart Hypoplasia.

INTRODUCTION: In a pilot study of chronic maternal hyperoxygenation (CMH) in left heart hypoplasia (LHH), we sought to determine effect estimates of CMH on head size, vascular resistance indices, and neurodevelopment compared to controls. MATERIAL AND METHODS: Nine gravidae meeting the inclusion criteria (fetal LHH, ≥25.9 weeks' gestation, and ≥10% increase in percent aortic flow after acute hyperoxygenation) were prospectively enrolled. Controls were 9 contemporary gravidae with fetal LHH without CMH. Brain growth and Doppler-derived estimates of fetal cerebrovascular and placental resistance were blindly evaluated and compared using longitudinal regression. Postnatal anthropomorphic and neurodevelopmental assessments were compared. RESULTS: There was no difference in baseline fetal measures between groups. There was significantly slower biparietal diameter (BPD) growth in the CMH group (z-score change -0.03 ± 0.02 vs. +0.09 ± 0.05 units/week, p = 0.02). At 6 months postnatal age, the mean head circumference z-score in the CMH group was smaller than that of controls (-0.20 ± 0.58 vs. +0.85 ± 1.11, p = 0.048). There were no differences in neurodevelopmental testing at 6 and 12 months. DISCUSSION: In this pilot study, relatively diminished fetal BPD growth and smaller infant head circumference z-scores at 6 months were noted with in utero CMH exposure.

The pediatric echocardiography Boot Camp: Four-year experience and impact on clinical performance.

BACKGROUND: We previously reported on the short-term impact of an echocardiography "Boot Camp" on a single class of cardiology fellows (CF). The impact of the Boot Camp on performance throughout fellowship is unknown. METHODS: We enrolled four classes of CFs and two classes of cardiac ICU fellows (CVs) prospectively into the Boot Camp and compared CFs to a historical cohort. Experience with echocardiography was surveyed. Outcome measures included written pre- and post-Camp exams, a performance based test (PBT), self-efficacy assessments, numbers of echocardiograms performed, and echocardiogram quality during the last 3 months of fellowship. RESULTS: A total of 25 CFs and 7 CVs participated in the Boot Camp from July 2012-July 2015. Median experience score was 13/40 (4-23). Median self-efficacy improved from 22/147 (range 21-45) to 90/147 (range 49-133) (P=<.001), and written scores from 14/29 (8-24) to 24/29 (13-29) (P<.001). CFs who completed the Boot Camp performed more independent echocardiograms compared to controls at the end of the 1st (37.7±12.2 vs 28.2±12.1, P=.15), 2nd (71.3±24.4 vs 47.6±16.0, P=.044), and third year of fellowship (130.4±44.0 vs 100.0±29.3, P=.230), and on average achieved 150 total echocardiograms in the 4.8th quarter compared to the 7.8th quarter in controls, P=.053. 2D quality scores were higher and shortening fraction more often obtained in echocardiograms performed by Boot Camp CFs compared to controls. CONCLUSIONS: The pediatric echocardiography Boot Camp improved self-efficacy, acquisition, and retention of echocardiography skills and knowledge, and increased echocardiogram performance. Observed differences between Boot Camp and control CFs appear to wane across fellowship.

Estimated combined cardiac output and laser therapy for twin-twin transfusion syndrome.

INTRODUCTION: Twin-twin transfusion syndrome (TTTS) is the major cause for fetal demise in monochorionic diamniotic pregnancies. Estimated combined cardiac output (CCO) has not been studied in this setting. The primary aims of this study were to compare CCO in twin donor and recipient fetuses and assess differences in CCO before and after laser coagulation therapy. A secondary aim was to evaluate the relationship of CCO with perinatal mortality, defined as intrauterine or neonatal mortality (≤30 days of age) in fetuses that underwent laser coagulation therapy. METHODS: We performed a retrospective review of fetuses with TTTS who received echocardiograms prior to laser therapy. Prelaser echocardiograms were performed in 66 fetuses, of which 45 (21 donor and 24 recipient) survived to the postlaser echocardiogram. RESULTS: Donor CCO increased from a mean of 487±137 mL/min/kg prelaser to 592±128 mL/min/kg postlaser (P=.025). There was no significant change in mean recipient CCO from prelaser 551±165 mL/min/kg to postlaser 575±112 mL/min/kg (P=.564). In recipient fetuses, higher prelaser CCO correlated with increasing Quintero stage (P=.010) and perinatal mortality (P=.003). Thirty-day postnatal outcome data were available for 38 fetuses, of whom 34 (89%) survived. Amongst survivors, 25 (74%) experienced an increase in CCO, while 9 (26%) experienced a decrease in CCO (P=.010). Donor fetuses had higher CCO after laser therapy. CONCLUSIONS: Higher prelaser CCO in recipient fetuses may indicate more advanced disease. Fetuses who exhibit a decrease in CCO after therapy laser may be at higher risk for perinatal mortality.

Echocardiographic Parameters and Outcomes in Primary Fetal Cardiomyopathy.

OBJECTIVES: Primary fetal cardiomyopathy is a rare entity, with a poor prognosis. We sought to describe its echocardiographic characteristics and outcomes. METHODS: We performed a 12-year retrospective review of fetuses with primary cardiomyopathy. RESULTS: Of more than 6000 fetuses evaluated, 25 met criteria for primary cardiomyopathy, and 18 had sufficient echocardiographic and pregnancy outcome data for inclusion. At echocardiography, the median gestational age was 29.6 weeks (range, 21.0-36.4 weeks); median cardiovascular profile score was 6 (range, 1-9); median right ventricular Tei index was 0.52 (range, 0.32-0.94); and median left ventricular Tei index was 0.40 (range, 0.15-0.88). Two had fetal demise, and 16 survived to delivery. The median cardiovascular profile score in those with fetal demise was 3.0 and in those who survived to delivery was 6.5 (range, 3-9; P = .14). The median right ventricular Tei index in those with fetal demise was 0.39 and in those surviving to delivery was 0.53 (range, 0.38-0.94; P = .49). The median left ventricular Tei index in those with fetal demise was 0.29 and in those surviving to delivery was 0.42 (range, 0.15-0.88; P = .50). Sixty-day survival was available in 11 of 16 fetuses. In addition to the 2 with fetal demise, 4 had postnatal demise, and 5 were alive at a median follow-up of 39 months. Hydrops (P = .01), skin edema (P = .01), and mild or greater mitral regurgitation (P = .02) were associated with fetal or postnatal demise, with a trend toward an association between moderate or greater tricuspid regurgitation (P = .07) and fetal or postnatal demise. CONCLUSIONS: Hydrops and atrioventricular valvar regurgitation are ominous signs in primary fetal cardiomyopathy. Although other commonly used methods for assessing cardiovascular performance may help in diagnosing primary cardiomyopathy, these data suggest limited predictive value.

Addressing Disparities in Pediatric Congenital Heart Disease: A Call for Equitable Health Care.

While significant progress has been made in reducing disparities within the US health care system, notable gaps remain. This article explores existing disparities within pediatric congenital heart disease care. Congenital heart disease, the most common birth defect and a leading cause of infant death, has garnered substantial attention, revealing certain disparities within the US health care system. Factors such as race, ethnicity, insurance coverage, socioeconomic status, and geographic location are all commonalities that significantly affect health disparities in pediatric congenital heart disease. This comprehensive review sheds light on disparities from diverse perspectives in pediatric care, demonstrates the inequities and inequalities leading to these disparities, presents effective solutions, and issues a call to action for providers, institutions, and the health care system. Recognizing and addressing these disparities is imperative for ensuring equitable care and enhancing the long-term well-being of children affected by congenital heart disease. Implementing robust, evidence-based frameworks that promote responsible and safe interventions is fundamental to enduring change.

Guidelines for Performing a Comprehensive Pediatric Transthoracic Echocardiogram: Recommendations From the American Society of Echocardiography.

Echocardiography is a fundamental component of pediatric cardiology, and appropriate indications have been established for its use in the setting of suspected, congenital, or acquired heart disease in children. Since the publication of guidelines for pediatric transthoracic echocardiography in 2006 and 2010, advances in knowledge and technology have expanded the scope of practice beyond the use of traditional modalities such as two-dimensional, M-mode, and Doppler echocardiography to evaluate the cardiac segmental structures and their function. Adjunct modalities such as contrast, three-dimensional, and speckle-tracking echocardiography are now used routinely at many pediatric centers. Guidelines and recommendations for the use of traditional and newer adjunct modalities in children are described in detail in this document. In addition, suggested protocols related to standard operations, infection control, sedation, and quality assurance and improvement are included to provide an organizational structure for centers performing pediatric transthoracic echocardiograms.

Targeted Neonatal Echocardiography in Patients With Hemodynamic Instability.

Targeted neonatal echocardiography (TNE) has been increasingly used at the bedside in neonatal care to provide an enhanced understanding of physiology, affecting management in hemodynamically unstable patients. Traditional methods of bedside assessment, including blood pressure, heart rate monitoring, and capillary refill are unable to provide a complete picture of tissue perfusion and oxygenation. TNE allows for precision medicine, providing a tool for identifying pathophysiology and to continually reassess rapid changes in hemodynamics. A relationship with cardiology is integral both in training as well as quality assurance. It is imperative that congenital heart disease is ruled out when utilizing TNE for hemodynamic management, as pathophysiology varies substantially in the assessment and management of patients with congenital heart disease. Utilizing TNE for longitudinal hemodynamic assessment requires extensive training. As the field continues to grow, guidelines and protocols for training and indications are essential for ensuring optimal use and providing a platform for quality assurance.

Left ventricular strain and left atrial strain are impaired during hemodialysis in children.

We aimed to investigate intradialytic changes in ventricular and atrial function using speckle tracking echocardiography (STE) in pediatric hemodialysis (HD). Children with HD vintage > 3 months were enrolled, and echocardiography was performed prior to, during, and after HD. STE was analyzed using GE EchoPAC. Left ventricular (LV) global longitudinal strain (GLS), strain rate (Sr), and mechanical dispersion index (MDI) were calculated as the average from 3 apical views; diastolic strain (Ds) and Sr from 4-chamber tracing; left atrial strain (LAS) and Sr from the 4- and 2-chamber views. A total of 15 patients were enrolled at a median age of 12 years (IQR 8, 16) and median HD vintage of 13 months (IQR 9, 25). GLS worsened during HD (- 15.8 ± 2.2% vs - 19.9 ± 1.9%, p < 0.001). Post-HD GLS was associated with BP decrease (coefficient = 0.62, p = 0.01). LV MDI and systolic Sr did not change. LV Ds progressively worsened (- 8.4% (- 9.2, - 8.0) vs - 11.9% (- 13.4, - 10.3), p < 0.001). LAS changes at mid-HD returned to baseline post-HD. Ds, DSr, LAS, LASr were not associated with BV removal or BP decrease (p > 0.1). In conclusions, intradialytic LV strain and LAS changes consistent with subclinical systolic and diastolic dysfunction were observed during HD in children. Changes in Ds, DSr, LAS, and LASr were not associated with BP change or BV removal and may be related to the disease progression. Longitudinal study using these novel indices may unfold the effect of these subclinical changes on long-term cardiovascular health in children requiring chronic HD.

ASE Statement on Adapting Pediatric, Fetal, and Congenital Heart Disease Echocardiographic Services to the Evolving COVID-19 Pandemic.

Over the 12 months since the start of the coronavirus disease 2019 pandemic, an explosion of investigation and an increase in experience have led to vast improvement in our knowledge about this disease. However, coronavirus disease 2019 remains a huge public health threat.

Transthoracic echocardiographic assistance for interatrial stenting in low birth-weight neonates with hypoplastic left heart syndrome and intact atrial septum.

Infants with hypoplastic left heart syndrome and intact or highly restrictive atrial septum require emergent therapy to relieve pulmonary congestion. Transcatheter stenting has become, in most large centers, the mainstay of therapy for relief of left atrial hypertension. Normally, this procedure is performed with the assistance of transesophageal echocardiographic guidance. However, the transesophageal approach is untenable in neonates of low birth weight, as the transducers can be traumatic and can cause ventilatory difficulty. We present two cases in which transthoracic echocardiographic guidance was used to guide atrial perforation and stenting in low birth-weight neonates with hypoplastic left heart syndrome with intact or highly restrictive atrial septum. Both procedures were straightforward and there were no complications. Real-time biplane imaging greatly assisted in the intervention in one case. The advantages of this approach are discussed.

Echocardiographic surveillance in children after tetralogy of Fallot repair: Adherence to guidelines?

BACKGROUND: Longitudinal clinical surveillance by transthoracic echocardiography (TTE) is an established practice in children with repaired tetralogy of Fallot (TOF). Non-Invasive Imaging Guidelines recommends a list of reporting elements that should be addressed during routine TTE in this population. In this study, we assessed the adherence to these recommendations. METHODS: This was a multi-center (n = 8) retrospective review of TTE reports in children ≤11 years of age who have had complete TOF repair. We included 10 patients from each participating center (n = 80) and scored 2 outpatient follow-up TTE reports on each patient. The adherence rate was based on completeness of TTE reporting elements derived from the guidelines. RESULTS: We reviewed 160 TTE reports on 80 patients. Median age was 4.4 months (IQR 1.5-6.6) and 3.6 years (IQR 1.3-6.4) at the time of complete surgical repair and first TTE report, respectively. The median adherence rate to recommended reporting elements was 61% (IQR 53-70). Of the 160 reports, 9 (7%) were ≥80% adherent and 40 (25%) were ≥70% adherent. Quantitative measurements of right ventricular outflow tract (RVOT), right ventricular (RV) size and function, and branch pulmonary arteries were least likely to be reported. CONCLUSIONS: Overall adherence to the most recent published imaging guidelines for surveillance of children with repaired TOF patients was suboptimal, especially for reporting of RVOT, RV size and function, and branch pulmonary arteries. Further studies are needed to explore the barriers to adherence to guidelines and most importantly, whether adherence is associated with clinical outcomes.

Comprehensive left ventricular myocardial deformation assessment in children with Kawasaki disease.

OBJECTIVE: Children with Kawasaki disease (KD) with persistent coronary artery aneurysms (CAAs) can develop chronic vasculopathy and subsequent myocardial ischemia. Early detection of this process is challenging. Myocardial deformation analysis can detect early alterations in myocardial performance. We aim to determine whether there are differences in myocardial deformation between KD patients with and without CAAs. DESIGN: This is a cross-sectional study of 123 echocardiograms performed on 103 children with KD. Myocardial deformation was measured with two-dimensional speckle tracking (2DSTE). The echocardiograms were divided into groups according to the KD phase in which they were performed: acute, subacute, and convalescent/chronic. The convalescent/chronic phase group was then divided based on the presence or absence of CAAs. Left ventricular (LV) global longitudinal strain (GLS), global longitudinal strain rate (GLSSR), global circumferential strain (GCS), global circumferential systolic strain rate (GCSSR), peak torsion, and torsion rate were measured. RESULTS: The numbers of echocardiograms analyzed in each of the KD phase groups were: 31 acute, 25 subacute, and 67 convalescent/chronic. Myocardial deformation was within normal limits in all groups. However, GLSSR, GCSSR, peak torsion, and torsion rate were lower in the convalescent/chronic phase group than in the acute phase group (mean, -1.37 ± 0.24 vs -1.55 ± 0.21 1/s; -1.63 ± 0.27 vs -1.84 ± 0.35 1/s; 2.49 ± 1.13 vs 3.41 ± 2.60 °/cm, and 21.97 ± 8.36 vs 26.69 ± 10.86 °/cm/s; P < .05 for all). The convalescent/chronic phase subgroup with CAAs had lower GLSSR and GCSSR than the subgroup without CAAs (mean, -1.23 ± 0.22 vs -1.42 ± 0.22 1/s; -1.46 ± 0.25 vs -1.68 ± 0.26 1/s, P < .05 for both). CONCLUSIONS: Children in the convalescent/chronic phase of KD have a subtle decrease in strain rate when compared to the acute phase, although within the normal range. This decrease is more pronounced in children with CAAs than those without CAAs. Longitudinal studies are needed to discern whether low-normal strain rate predicts decreased myocardial function in the long term.

Etanercept With IVIg for Acute Kawasaki Disease: A Randomized Controlled Trial.

OBJECTIVES: Patients with Kawasaki disease can develop life-altering coronary arterial abnormalities, particularly in those resistant to intravenous immunoglobulin (IVIg) therapy. We tested the tumor necrosis factor α receptor antagonist etanercept for reducing both IVIg resistance and coronary artery (CA) disease progression. METHODS: In a double-blind multicenter trial, patients with Kawasaki disease received either etanercept (0.8 mg/kg; n = 100) or placebo (n = 101) subcutaneously starting immediately after IVIg infusion. IVIg resistance was the primary outcome with prespecified subgroup analyses according to age, sex, and race. Secondary outcomes included echocardiographic CA measures within subgroups defined by coronary dilation (z score >2.5) at baseline. We used generalized estimating equations to analyze z score change and a prespecified algorithm for change in absolute diameters. RESULTS: IVIg resistance occurred in 22% (placebo) and 13% (etanercept) of patients (P = .10). Etanercept reduced IVIg resistance in patients >1 year of age (P = .03). In the entire population, 46 (23%) had a coronary z score >2.5 at baseline. Etanercept reduced coronary z score change in those with and without baseline dilation (P = .04 and P = .001); no improvement occurred in the analogous placebo groups. Etanercept (n = 22) reduced dilation progression compared with placebo (n = 24) by algorithm in those with baseline dilation (P = .03). No difference in the safety profile occurred between etanercept and placebo. CONCLUSIONS: Etanercept showed no significant benefit in IVIg resistance in the entire population. However, preplanned analyses showed benefit in patients >1 year. Importantly, etanercept appeared to ameliorate CA dilation, particularly in patients with baseline abnormalities.

Clinical assessment of coronary arteries in Kawasaki disease: Focus on echocardiographic assessment.

Echocardiography is an excellent noninvasive imaging modality for evaluation and follow-up of cardiac lesions, especially coronary artery changes occurring as a result of Kawasaki disease. The information obtained has prognostic implications and can be complemented with other modes of imaging for risk stratification and optimization of both medical and interventional therapy. The aim of this article is to describe the time line of echocardiographic follow-up of patients affected with Kawasaki disease. The classification of coronary artery changes and transthoracic echocardiographic views recommended for detailed evaluation of the coronary arteries are delineated in detail in this report.

Left ventricular rotational mechanics in early infancy: Normal reference ranges and reproducibility of peak values and time to peak values.

INTRODUCTION: Left ventricular cardiac twist and torsion values have been described in premature and term neonates, but not in early infancy. Early and late peak untwist rates and time to peak (TTP) values have not been described in infants. METHODS: 53 term infants were enrolled prospectively. The following parameters were obtained by two blinded observers at 1-2months postnatal age: peak twist and torsion (twist indexed to LV length), peak twist rate and torsion rate, TTP twist, early peak untwist rate, TTP early untwist rate, late peak untwist rate, TTP late untwist rate. Reproducibility was assessed using intraclass correlation and Bland Altman analysis. RESULTS: Intraclass correlation was ≥0.87 for all peak rotational mechanics values. Measures of TTP values had intraclass correlation (ICC) values ≤0.77, with TTP twist rate demonstrating the lowest ICC (0.69). The only measure which demonstrated significant bias was TTP twist rate. Peak twist demonstrated modest correlation (R=0.52, p<0.001) with global circumferential strain, and no correlation with ejection fraction, global longitudinal strain, or left ventricular myocardial performance index. CONCLUSIONS: Measurements of rotational mechanics and timing to peak values have acceptable reproducibility. Peak twist, twist rate, and early untwist rate values in early infancy are similar to those reported in premature neonates, and higher than those reported in older children. Twist indexed to LV length (torsion) is lower in early infancy than in premature neonates, but higher than in term neonates.