Normative computed tomography angiography values of the main and branch pulmonary arteries in children.

Non-invasive cardiac imaging like echocardiogram, cardiac magnetic resonance imaging (CMR), and computed tomography angiography (CTA) play a key role in the diagnosis, aid in management and follow-up of congenital heart disease patients. Normative data for intracardiac and extracardiac vascular structures in children are currently available for echocardiogram, CMR, and non-gated CTA. We sought to establish systolic and diastolic normative data for main and branch pulmonary arteries in children using electrocardiogram (ECG)-gated CTA. Diameters and cross-sectional areas of the main and branch pulmonary arteries were measured in systole and diastole based on the aortic valve position (open versus closed) in 100 subjects who had ECG-gated cardiac CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface area (BSAAE) was established using the previously described methods. A total of 100 children aged 0-18 years were analyzed; mean age was 5.3 years (SD, 6.1 years). Z-score curves were plotted in relation to the BSA for the mean, maximum, and minimum diameters and cross-sectional area of the main and branch pulmonary arteries for systole and diastole.   Conclusion: We report systolic and diastolic mean, maximum, and minimum diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children derived using ECG-gated cardiac CTA. We believe our results can help identify abnormally sized main and branch pulmonary arteries. What is Known: • Normative data for intracardiac and extracardiac vascular structures in the pediatric population are available for echocardiography, cardiac MRI and non-ECG gated CTA. • Z-scores with standard deviations are commonly used in children, but SDs are not constant across body sizes due to heteroscedasticity. What is New: • Allometric exponent was derived for each parameter and the parameter/body surface area (BSA) was established. • This is the first ECG-gated CTA study to provide normative en face systolic, diastolic diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children.

Role of Cardiac CTA to Evaluate Branch Pulmonary Artery Stenosis and Ductal Insertion Pattern in Right-Sided Congenital Heart Defects.

There is limited experience in evaluating abnormal ductus arteriosus (DA) insertion pattern by contrast-enhanced cardiac computed tomography (cardiac CT) in patients with right-sided obstructive cardiac defects. Retrospective review of 38 infants with right-sided obstructive cardiac defects who underwent a preoperative cardiac CT between 2016 and 2021. We reviewed the types of cardiac lesions, patterns of ductal insertion, frequency of pulmonary artery (PA) stenosis requiring intervention, total dose length product (DLP), and effective radiation dose. Of 38 infants, 45% were female, the median gestational age and weight were 37 (range 34-40) weeks and 2.95 (range 2-4) kg. The most common pathologies were pulmonary atresia with ventricular septal defect (24%) and tetralogy of Fallot (24%). The abnormal ductal insertion patterns were DA inserting into the left PA in 39%, DA bifurcating into branch PA in 32%, and DA inserting into the right PA in 13%. Of the 38 infants, 76% developed branch PA stenosis requiring intervention. Among patients with abnormal DA insertion, 44% required branch PA arterioplasty during their index surgery compared to 17% without abnormal DA insertion. Regardless of the type of abnormal DA insertion, 67% developed bilateral branch PA stenosis over time. The mean DLP was 8 mGy-cm and the mean calculated effective radiation dose was 0.312 mSv. The utilization of contrast-enhanced cardiac CT in infants with right-sided obstructive heart defects can offer crucial insights into abnormal ductus arteriosus insertion patterns. This information is valuable for effective procedure planning and for monitoring the development of branch pulmonary artery stenosis.

Pre- and post-operative cardiovascular CT in Stage I single ventricle palliation.

OBJECTIVES: The aim of this study is to describe clinical utility of low dose cardiac computed tomography (CT) in the evaluation of single ventricle physiology before and after Stage I palliation. BACKGROUND: Despite the increased utilization of CT imaging and advancement of CT technology, there are limited studies describing the routine clinical use of cardiac CT and radiation dose parameters in the single ventricle Stage I palliation. METHODS: This single center, retrospective study included 57 infants with single ventricle physiology who underwent cardiac CT scans between January 1, 2016 and November 30, 2020. Patients' demographic information, diagnosis, indication, total dose length product (DLP), computed tomographic dose index volume (CTDIvol), cardiac CT findings and intraoperative or intraprocedural findings were reviewed. Estimated effective radiation dose was calculated using a previously published conversion rate. RESULTS: The studies were performed using different generations of CT scanners over the 4 years period: Somatom AS 128, Somatom definition edge, Somatom Force (Siemens Medical Solutions). The studies performed with dual source scanner with prospective gated technique have lower radiation dose exposure with median effective radiation dose of 0.32 mSv. CONCLUSION: Pre- and post-operative cardiovascular CT in Stage I single ventricle palliation using newer generation scanners with prospective gated technique can be done with minimal radiation exposure and good image quality. Cardiac CT is a powerful imaging modality for better management planning in this group of patients.

Modern advances regarding interatrial communication in congenital heart defects.

BACKGROUND: The interatrial communication, one of the most frequent congenital heart defects, represents an important intracardiac shunt between systemic and pulmonary circulations. Direction and magnitude of the interatrial shunting depends upon several features, including defect size, shape and location, pressure difference between right and left atrium, and difference in right and left ventricular compliance. METHODS: In this review article, the presence or absence of interatrial communication, and its role, have been analyzed, as they can have a critical impact on the cardiovascular physiopathology, and the interatrial communication can prove to be either clinically harmful, useful or indispensable. Accordingly, the utility and role of the interatrial communication in modern congenital, pediatric and adult, disease has evolved, with modification of the indications to close, maintain patency, or create an interatrial communication. RESULTS: The interatrial communication and shunting can be manipulated to maximize the oxygen delivery to the tissues, accordingly with the underlying congenital heart defect. While not always relevant to patients with bi-ventricular circulations, this becomes extremely important in children and adults with complex congenital heart defects. CONCLUSIONS: With improving long-term survival for the vast majority of congenital heart patients, an advanced understanding of the role and utility of the interatrial communication, and of all the possibilities of its manipulation, is essential to improve the patient outcomes.

Essential role of cardiac computed tomography for surgical decision making in children with total anomalous pulmonary venous connection and single ventricle.

BACKGROUND: Total anomalous pulmonary venous connection (TAPVC) is a major risk factor in infants with single ventricle (SV). Exact definition of TAPVC anatomy is crucial for surgical planning. AIM: To evaluate the role of cardiac computed tomography (CT) in this setting. METHODS: Retrospective review of 13 infants who underwent TAPVC repair associated with SV from May 2016 to October 2021. Anatomy, incidence, and mechanisms of pulmonary venous obstruction (PVO) were described. Cardiac CT diagnostic yield was compared to echocardiography (echo). RESULTS: Of 13 infants, median age and weight were 24 days (range 2-303 days) and 3.2 (range 2.6-9.1) kg, 8 (62%) were male, 4 (31%) premature, and 11 (85%) had heterotaxy syndrome. All infants had pre- and postoperative echo; 13 had preoperative and 8 (62%) had postoperative cardiac CT. Type of TAPVC: six (46%) supracardiac, two (15%) intracardiac, one (8%) infracardiac, and four (31%) mixed, with pulmonary veins draining in >1 confluence in nine (69%). PVO was present in 6/13 (46%) preoperatively and 5/13 (31%) postoperatively. Mechanisms of PVO: 9/11 (82%) stenosis, 1/9 (9%) membrane formation, and 1/9 (9%) external compression. The sensitivity to diagnose PVO was 45.5% for echo and 100% for cardiac CT, the specificity was 100% for both. No discrepancy was found between cardiac CT and intraoperative findings, but echo had a complete preoperative diagnosis in 1/13 (8%) (p < .00001, Fisher exact test). CONCLUSIONS: Cardiac CT is essential to evaluate pre- and postoperative TAPVC in SV for surgical decision making and long term follow up.

The role of computational methods in cardiovascular medicine: a narrative review.

Background and Objective: Computational models of the cardiovascular system allow for a detailed and quantitative investigation of both physiological and pathological conditions, thanks to their ability to combine clinical-possibly patient-specific-data with physical knowledge of the processes underlying the heart function. These models have been increasingly employed in clinical practice to understand pathological mechanisms and their progression, design medical devices, support clinicians in improving therapies. Hinging upon a long-year experience in cardiovascular modeling, we have recently constructed a computational multi-physics and multi-scale integrated model of the heart for the investigation of its physiological function, the analysis of pathological conditions, and to support clinicians in both diagnosis and treatment planning. This narrative review aims to systematically discuss the role that such model had in addressing specific clinical questions, and how further impact of computational models on clinical practice are envisaged. Methods: We developed computational models of the physical processes encompassed by the heart function (electrophysiology, electrical activation, force generation, mechanics, blood flow dynamics, valve dynamics, myocardial perfusion) and of their inherently strong coupling. To solve the equations of such models, we devised advanced numerical methods, implemented in a flexible and highly efficient software library. We also developed computational procedures for clinical data post-processing-like the reconstruction of the heart geometry and motion from diagnostic images-and for their integration into computational models. Key Content and Findings: Our integrated computational model of the heart function provides non-invasive measures of indicators characterizing the heart function and dysfunctions, and sheds light on its underlying processes and their coupling. Moreover, thanks to the close collaboration with several clinical partners, we addressed specific clinical questions on pathological conditions, such as arrhythmias, ventricular dyssynchrony, hypertrophic cardiomyopathy, degeneration of prosthetic valves, and the way coronavirus disease 2019 (COVID-19) infection may affect the cardiac function. In multiple cases, we were also able to provide quantitative indications for treatment. Conclusions: Computational models provide a quantitative and detailed tool to support clinicians in patient care, which can enhance the assessment of cardiac diseases, the prediction of the development of pathological conditions, and the planning of treatments and follow-up tests.

Computed Tomography Tissue Characterization of Pediatric Cardiac Tumor.

Little is known about tissue characterization of cardiac tumors by dedicated cardiac computed tomography (CT) protocols in pediatric patients. We report using arterial and delayed CT acquisitions to characterize a large left ventricular free wall tumor in a 12-year-old female with congenital mitral insufficiency and an automatic implantable cardioverter defibrillator. (Level of Difficulty: Intermediate.).

Virtual Simulated Implantation of an Adult-Sized Left Ventricular Assist Device in a Pediatric Patient.

There is very limited experience with simulated virtual implantation of left ventricular assist devices (LVADs) to assess device fitness in pediatric patients. In this clinical vignette, we report the case of a 9-year-old male patient with dilated cardiomyopathy who underwent successful placement of an LVAD after virtual simulated implantation was performed. (Level of Difficulty: Advanced.).

Evaluation of complex congenital heart disease in infants using low dose cardiac computed tomography.

Despite advances in new CT techniques with radiation dose reduction, there are limited studies describing radiation dose. Describing radiation dose might help to educate physicians on how the benefit of cardiac CT outweighs the potential risk of radiation. The aim of this study was to describe the radiation exposure parameters in newborns and infants and the role of CT scan in providing useful information for optimal surgical planning and management of newborns and infants with complex congenital heart disease. In complex congenital heart disease delineating the anatomy and using the CT images as needed for three-dimensional modelling helps for optimal surgical planning. This single center, retrospective study included 74 infants with CHD (median age 2 months, range 1 day to 9 months) who underwent cardiac CT evaluation from September 2018 to April 2019, using the Siemens Somatom Definition Edge scanner. Total dose length product (DLP) and computed tomographic dose index volume (CTDIvol) were recorded, and the estimated effective radiation dose was calculated using a previously published conversion rate. Median effective radiation dose for the computed tomographic angiography (CTA) was 0.6 mSv. The median DLP was 13 mGycm and median CTDIvol was 3.5 mGy. Cardiac CT can be done with a sub-mSv dose in infants. Cardiac CT completes the standard initial evaluation of neonates and infants with complex CHD, allowing thorough understanding of complex spatial relationships between anatomical and defective structures, and is achievable with minimal radiation exposure.

Perioperative Anomalous Pulmonary Venous Return Evaluation With Low-Dose Cardiac Computed Tomography.

BACKGROUND: Low-dose multidetector computed tomographic angiography (MDCTA) is playing an increasingly larger role in the diagnosis of anomalous pulmonary venous return (APVR). Despite advances in new computed tomographic (CT) techniques with radiation dose reduction, there are limited studies describing radiation dose parameters to allow routine use of cardiac CT in infants and children with APVR. This study compares cardiac CT findings with intraoperative findings and describes comprehensive radiation exposure parameters. METHODS: A retrospective analysis of 27 patients compared MDCTA and intraoperative or cardiac catheterization findings of the pulmonary venous anatomy. RESULTS: A total of 32 MDCTA studies were performed on these 27 patients. Of the 28 studies with subsequent intervention, MDCTA accurately diagnosed the anomalous pulmonary venous anatomy in 27 (96.4%) patients. Narrowing of the pulmonary venous confluence entrance to the coronary sinus was missed on cardiac CT in one patient due to motion artifact, but it was noted intraoperatively. Median estimated effective radiation dose was 0.98 mSv (range: 0.39-3.2 mSv), and mean estimated effective radiation dose was 1.1 ± 0.68 mSv. Median total dose length product (DLP) was 25 mGy cm (range: 10-83 mGy cm), and mean total DLP was 28 ± 18 mGy cm. Median CTDI volume was 3.8 mGy (range: 2.5-14.6 mGy), and mean CTDI volume was 5.0 ± 3.2 mGy. CONCLUSIONS: We conclude that modern cardiac MDCTA is the best imaging modality to guide management in both preintervention and postintervention APVR patients. In this study, we describe comprehensive radiation exposure parameters in infants and children with APVR.