Narrowing Down the Symptomatology of Isolated Vascular Rings in Children.

Vascular rings may cause respiratory or gastrointestinal symptoms due to compression of the trachea and/or esophagus. Advances in imaging have enabled early detection in asymptomatic patients posing new management dilemmas. Surgery is expected to relieve symptoms, although this has not been well studied. We sought to evaluate the presence and pattern of symptoms associated with vascular rings before surgical intervention and to detail symptom resolution after surgery. A 10-year retrospective review of patients diagnosed with an isolated vascular ring was performed between January 2010 and December 2019. 100 patients were identified; 35 double aortic arch (DAA) and 65 right aortic arch and left ligamentum arteriosum (RALL). 73 patients were symptomatic on presentation; 47 had respiratory, 5 had gastrointestinal, and 21 had both types of symptoms. Surgical repair was performed in 75 patients; 74 were symptomatic. Respiratory symptoms were more likely in patients with preoperative tracheal narrowing (p < 0.001). Moderate-severe respiratory symptoms led to surgery in RALL patients (OR 10.6, p = 0.0001). DAA patients were more likely to undergo surgery (p < 0.001) irrespective of symptom severity. At a median post-surgical follow-up of 4 months, there was a significant reduction in symptom burden (p < 0.001), except for asthma symptoms (p = 0.131). Symptom resolution was not dependent on the vascular ring anatomy (p = 0.331) or the age at operation (p = 0.158). Vascular rings are typically accompanied by respiratory symptoms and less commonly GI symptoms, both of which resolve in most patients after surgery. Those who present predominantly with asthma-like symptoms may not achieve resolution after surgery.

Longitudinal Assessment of Cardiac Function Following Multisystem Inflammatory Syndrome in Children Associated with COVID-19.

Multisystem inflammatory syndrome in children (MIS-C) after COVID-19 is commonly associated with cardiac involvement. Studies found myocardial dysfunction, as measured by decreased ejection fraction and abnormal strain, to be common early in illness. However, there is limited data on longitudinal cardiac outcomes. We aim to describe the evolution of cardiac findings in pediatric MIS-C from acute illness through at least 2-month follow-up. A retrospective single-center review of 36 patients admitted with MIS-C from April 2020 through September 2021 was performed. Echocardiographic data including cardiac function and global longitudinal strain (GLS) were analyzed at initial presentation, discharge, 2-4-week follow-up, and at least 2-month follow-up. Patients with mild and severe disease, normal and abnormal left ventricular ejection fraction (LVEF), and normal and abnormal GLS at presentation were compared. On presentation, 42% of patients with MIS-C had decreased LVEF < 55%. In patients in whom GLS was obtained (N = 18), 44% were abnormal (GLS < |- 18|%). Of patients with normal LVEF, 22% had abnormal GLS. There were no significant differences in troponin or brain natriuretic peptide between those with normal and abnormal LVEF. In most MIS-C patients with initial LVEF < 55% (90%), LVEF normalized upon discharge. At 2-month follow-up, all patients had normal LVEF with 21% having persistently abnormal GLS. Myocardial systolic dysfunction and abnormal deformation were common findings in MIS-C at presentation. While EF often normalized by 2 months, persistently abnormal GLS was more common, suggesting ongoing subclinical dysfunction. Our study offers an optimistic outlook for recovery in patients with MIS-C and carditis, however ongoing investigation for longitudinal effects is warranted.

Using DaSilva Cone Operation to Establish 1.5 or 2 Ventricle Circulation After Initial Single Ventricle Palliation with Starnes Procedure.

Ebstein anomaly (EA) is a congenital dysplasia of the tricuspid valve resulting in reduced right ventricular (RV) volume and tricuspid regurgitation. Severe EA in the neonatal period is associated with high mortality. The Starnes procedure (fenestrated RV exclusion) is reserved for EA patients with cardiogenic shock and has previously committed patients to single ventricle (SV) palliation. In this report, we present the results of a strategy to redirect patients utilizing the Da Silva Cone operation to achieve a 2 or 1.5 ventricle circulation. Single-center retrospective study including all consecutive cases of Da Silva Cone operation after Starnes procedure. Between 2019 and 2023, six conversions from Starnes procedure to Cone reconstruction were performed. All were critically ill before their Starnes procedure; four on extracorporeal membrane oxygenation. Two patients were successfully rerouted to a two-ventricle repair; the remainder to 1.5 ventricle circulation. RV pressure estimates showed no correlation with success. Post-Cone intensive care and hospital stays were brief, median 5 and 6 days, respectively. All are between 2.5 and 6 years old, without indications for SV palliation. There were no deaths, with follow up ranging 1 month-4 years. No repeat interventions were performed on the tricuspid valves. One subject had a surgical pulmonary valve replacement. Tricuspid regurgitation was mild in all. The Da Silva Cone operation offers successful redirection of EA patients from a SV pathway to a 1.5 or 2 ventricle pathway after Starnes procedure. The approach is feasible and durable in midterm follow-up. The decision to initially proceed with Starnes need not be an irrevocable decision to continue down a SV palliation pathway.

Multimodality Imaging in Ebstein Anomaly.

Ebstein anomaly is the most common form of tricuspid valve congenital anomalies. The tricuspid valve is abnormal with different degrees of displacement of the septal leaflet and abnormal rotation of the valve towards the right ventricular outflow tract. In severe forms, it results in significant tricuspid regurgitation and requires surgical repair. There is an increased interest in understanding the anatomy of the tricuspid valve in this lesion as the surgical repair has evolved with the invention and wide adoption of the cone operation. Multimodality imaging plays an important role in diagnosis, follow-up, surgical planning and post-operative care. This review provides anatomical tips for the cardiac imagers caring for patients with Ebstein anomaly and will help provide image-based personalized medicine.

The role of machine learning applications in diagnosing and assessing critical and non-critical CHD: a scoping review.

Machine learning uses historical data to make predictions about new data. It has been frequently applied in healthcare to optimise diagnostic classification through discovery of hidden patterns in data that may not be obvious to clinicians. Congenital Heart Defect (CHD) machine learning research entails one of the most promising clinical applications, in which timely and accurate diagnosis is essential. The objective of this scoping review is to summarise the application and clinical utility of machine learning techniques used in paediatric cardiology research, specifically focusing on approaches aiming to optimise diagnosis and assessment of underlying CHD. Out of 50 full-text articles identified between 2015 and 2021, 40% focused on optimising the diagnosis and assessment of CHD. Deep learning and support vector machine were the most commonly used algorithms, accounting for an overall diagnostic accuracy > 0.80. Clinical applications primarily focused on the classification of auscultatory heart sounds, transthoracic echocardiograms, and cardiac MRIs. The range of these applications and directions of future research are discussed in this scoping review.

Motion-corrected cardiac MRI is associated with decreased anesthesia exposure in children.

BACKGROUND: The benefits of cardiac magnetic resonance imaging (MRI) in the pediatric population must be balanced with the risk and cost of anesthesia. Segmented imaging using multiple averages attempts to avoid breath-holds requiring general anesthesia; however, cardiorespiratory artifacts and prolonged scan times limit its use. Thus, breath-held imaging with general anesthesia is used in many pediatric centers. The advent of free-breathing, motion-corrected (MOCO) cines by real-time re-binned reconstruction offers reduced anesthesia exposure without compromising image quality. OBJECTIVE: This study evaluates sedation utilization in our pediatric cardiac MR practice before and after clinical introduction of free-breathing MOCO imaging for cine and late gadolinium enhancement. MATERIALS AND METHODS: In a retrospective study, patients referred for a clinical cardiac MR who would typically be offered sedation for their scan (n=295) were identified and divided into two eras, those scanned before the introduction of MOCO cine and late gadolinium enhancement sequences and those scanned following their introduction. Anesthesia use was compared across eras and disease-specific cohorts. RESULTS: The incidence of non-sedation studies performed in children nearly tripled following the introduction of MOCO imaging (25% [pre-MOCO] to 69% [post-MOCO], P<0.01), with the greatest effect in patients with simple congenital heart disease. Eleven percent of the post-MOCO cohort comprised infants younger than 3 months of age who could forgo sedation with the combination of MOCO imaging and a "feed-and-bundle" positioning technique. CONCLUSION: Implementation of cardiac MR with MOCO cine and late gadolinium enhancement imaging in a pediatric population is associated with significantly decreased sedation utilization.

Myocardial Parametric Mapping by Cardiac Magnetic Resonance Imaging in Pediatric Cardiology and Congenital Heart Disease.

Parametric mapping, that is, a pixel-wise map of magnetic relaxation parameters, expands the diagnostic potential of cardiac magnetic resonance by enabling quantification of myocardial tissue-specific magnetic relaxation on an absolute scale. Parametric mapping includes T1 mapping (native and postcontrast), T2 and T2* mapping, and extracellular volume measurements. The myocardial composition is altered in various disease states affecting its inherent magnetic properties and thus the myocardial relaxation times that can be directly quantified using parametric mapping. Parametric mapping helps in the diagnosis of nonfocal disease states and allows for longitudinal disease monitoring, evaluating therapeutic response (as in Thalassemia patients with iron overload undergoing chelation), and risk-stratification of certain diseases. In this review article, we describe various mapping techniques and their clinical utility in congenital heart disease. We will also review the available literature on normative values in children, the strengths, and weaknesses of these techniques. This review provides a starting point for pediatric cardiologists to understand and implement parametric mapping in their practice.

Design and rationale of a clinical trial to increase cardiomyocyte division in infants with tetralogy of Fallot.

BACKGROUND: Patients with Tetralogy of Fallot with pulmonary stenosis (ToF/PS), the most common form of cyanotic congenital heart disease (CHD), develop adverse right ventricular (RV) remodeling, leading to late heart failure and arrhythmia. We recently demonstrated that overactive ß-adrenergic receptor signaling inhibits cardiomyocyte division in ToF/PS infants, providing a conceptual basis for the hypothesis that treatment with the ß-adrenergic receptor blocker, propranolol, early in life would increase cardiomyocyte division. No data are available in ToF/PS infants on the efficacy of propranolol as a possible novel therapeutic option to increase cardiomyocyte division and potentially reduce adverse RV remodeling. METHODS: Using a randomized, double-blind, placebo-controlled trial, we will evaluate the effect of propranolol administration on reactivating cardiomyocyte proliferation to prevent adverse RV remodeling in 40 infants with ToF/PS. Propranolol administration (1 mg/kg po QID) will begin at 1 month of age and last until surgical repair. The primary endpoint is cardiomyocyte division, quantified after 15N-thymidine administration with Multi-isotope Imaging Mass Spectrometry (MIMS) analysis of resected myocardial specimens. The secondary endpoints are changes in RV myocardial and cardiomyocyte hypertrophy. CONCLUSION: This trial will be the first study in humans to assess whether cardiomyocyte proliferation can be pharmacologically increased. If successful, the results could introduce a paradigm shift in the management of patients with ToF/PS from a purely surgical approach, to synergistic medical and surgical management. It will provide the basis for future multi-center randomized controlled trials of propranolol administration in infants with ToF/PS and other types of CHD with RV hypertension. CLINICAL TRIAL REGISTRATION: The trial protocol was registered at clinicaltrials.gov (NCT04713657).

Diastolic velocity half time is associated with aortic coarctation gradient at catheterization independent of echocardiographic and clinical blood pressure gradients.

OBJECTIVE: The most accurate noninvasive parameter to predict whether a patient with aortic coarctation will meet interventional criteria at catheterization remains elusive. We aim to determine the best independent echocardiographic predictors of a coarctation peak-to-peak pressure gradient ≥20 mm Hg at catheterization, the accepted threshold for intervention. DESIGN: Retrospective query of our catheterization database from 1/2007 to 7/2016 for the diagnostic code of aortic coarctation was performed. Multiple echocardiographic measurements and blood pressure gradients prior to cardiac catheterization were collected. Univariate correlation of variables with the continuous catheterization peak were calculated using Spearman's rho. Univariate association with peak-to-peak gradient at catheterization ≥20 mm Hg was tested using Mann-Whitney U test and the Pearson chi-square test or Fisher's exact test. Multivariable logistic regression assessed the independent association of the clinically relevant metrics with gradient at catheterization ≥20 mm Hg. RESULTS: Sixty-eight patients met study criteria (median age 9.25 years), of whom 84% underwent intervention at catheterization. Echocardiographic peak and mean coarctation velocity, indexed systolic and diastolic velocity half times (SVHTi, DVHTi), and blood pressure gradient all had moderate correlation (Spearman's rho = 0.529-0.617, P < .001) with the continuous catheterization gradient and were significantly associated with the binary outcome of catheterization peak ≥20 mm Hg (P < .001). Logistic regression found echocardiographic mean systolic gradient (OR 1.213 [95% CI 1.041-1.414]) and DVHTi (OR 1.039 [95% CI 1.004-1.074]) independently associate with catheterization peak ≥20 mm Hg after controlling for blood pressure gradient (OR 1.066 [0.987-1.150]). CONCLUSIONS: Most echocardiographic estimates show moderate correlation with arch gradient at catheterization. Noninvasive four extremity blood pressure gradient is significantly associated with peak-to-peak gradient ≥20 mm Hg. DVHTi may provide a unique independently associated echocardiographic estimate of coarctation severity. Further study of these variables with larger cohorts may allow for development of predictive models to direct catheterization.

The effects of temperature and anesthetic agents on ciliary function in murine respiratory epithelia.

BACKGROUND: Mucus transport mediated by motile cilia in the airway is an important defense mechanism for prevention of respiratory infections. As cilia motility can be depressed by hypothermia or exposure to anesthetics, in this study, we investigated the individual and combined effects of dexmedetomidine (dex), fentanyl (fen), and/or isoflurane (iso) at physiologic and low temperatures on cilia motility in mouse tracheal airway epithelia. These anesthetic combinations and low temperature conditions are often used in the setting of cardiopulmonary bypass surgery, surgical repair of congenital heart disease, and cardiac intensive care. METHODS: C57BL/6J mouse tracheal epithelia were excised and cilia dynamics were captured by videomicroscopy following incubation at 15, 22-24, and 37°C with different combinations of therapeutic concentrations of dex (10 nM), fen (10 nM), and iso (0.01%). Airway ciliary motion was assessed and compared across conditions by measuring ciliary beat frequency and ciliary flow velocity. Statistical analysis was carried out using unpaired t-tests, analysis of variance, and multivariate linear regression. RESULTS: There was a linear correlation between cilia motility and temperature. Fen exerted cilia stimulatory effects, while dex and iso each had ciliodepressive effects. When added together, fen + iso, dex + iso, and dex + fen + iso were all cilia inhibitory. In contrast fenl + dex did not significantly alter ciliary function. CONCLUSION: We show that ciliary motility is stimulated by fen, but depressed by dex or iso. However, when used in combination, ciliary motility showed changes indicative of complex drug-drug and drug-temperature interactions not predicted by simple summation of their individual effects. Similar studies are needed to examine the human airway epithelia and its response to anesthetics.

Immortal coils: conserved dimerization motifs of the Drosophila ovulation prohormone ovulin.

Dimerization is an important feature of the function of some proteins, including prohormones. For proteins whose amino acid sequences evolve rapidly, it is unclear how such structural characteristics are retained biochemically. Here we address this question by focusing on ovulin, a prohormone that induces ovulation in Drosophila melanogaster females after mating. Ovulin is known to dimerize, and is one of the most rapidly evolving proteins encoded by the Drosophila genome. We show that residues within a previously hypothesized conserved dimerization domain (a coiled-coil) and a newly identified conserved dimerization domain (YxxxY) within ovulin are necessary for the formation of ovulin dimers. Moreover, dimerization is conserved in ovulin proteins from non-melanogaster species of Drosophila despite up to 80% sequence divergence. We show that heterospecific ovulin dimers can be formed in interspecies hybrid animals and in two-hybrid assays between ovulin proteins that are 15% diverged, indicating conservation of tertiary structure amidst a background of rapid sequence evolution. Our results suggest that because ovulin's self-interaction requires only small conserved domains, the rest of the molecule can be relatively tolerant to mutations. Consistent with this view, in comparisons of 8510 proteins across 6 species of Drosophila we find that rates of amino acid divergence are higher for proteins with coiled-coil protein-interaction domains than for non-coiled-coil proteins.