Subjective and Objective Sonographic Assessment for the Prenatal Detection of Neonatal Coarctation of the Aorta.

INTRODUCTION: The objective of this study was to assess the performance of antenatal ultrasound markers in detecting neonatal coarctation of the aorta (CoA). METHODS: We performed a retrospective study including fetuses with suspected CoA and no other cardiac abnormalities. Data obtained from antenatal ultrasounds included subjective assessment of ventricular and arterial asymmetry, appearance of aortic arch, presence of a persistent left superior vena cava, and objective Z-score measurements of the mitral, tricuspid, aortic (AV), and pulmonary (PV) valves. Performance of antenatal ultrasound markers in predicting postnatal CoA was then assessed. RESULTS: Of the 83 fetuses referred for suspected CoA, 30 (36.1%) had confirmed CoA postnatally. The sensitivity and specificity for antenatal diagnosis were 83.3% (95% confidence interval [CI]: 65.3-94.4%) and 45.3% (95% CI: 31.6-59.6%), respectively. Neonates with confirmed CoA had lower mean AV Z-scores (-2.1 vs. -1.1, p = 0.01), higher PV Z-scores (1.6 vs. 0.8, p = 0.03), and a lower AV/PV ratio (0.5 vs. 0.6, p < 0.001). Subjective assessments of symmetry and the incidence of persistent left superior vena cava did not differ between groups. Among the variables studied, the most promising marker for CoA was the AV/PV ratio (area under the receiver operating characteristics curve 0.81, 95% CI: 0.67-0.94). CONCLUSION: The use of objective sonographic markers, in particular measurements of the AV and PV, shows a trend toward an improvement in prenatal detection of CoA. Confirmation in larger studies is required.

Quantitative assessment of velocity and flow using compressed SENSE in children and young adults with adequate acquired temporal resolution.

BACKGROUND: Phase contrast (PC) cardiovascular magnetic resonance (CMR) imaging with parallel imaging acceleration is established and validated for measuring velocity and flow. However, additional acceleration to further shorten acquisition times would be beneficial in patients with complex vasculature who need multiple PC-CMR measurements, especially pediatric patients with higher heart rates. METHODS: PC-CMR images acquired with compressed sensitivity encoding (C-SENSE) factors of 3 to 6 and standard of care PC-CMR with sensitivity encoding (SENSE) factor of 2 (S2) acquired as part of clinical CMR examinations performed between November 2020 and January 2021 were analyzed retrospectively. The velocity and flow through the ascending aorta (AAo), descending aorta (DAo), and superior vena cava (SVC) in a transverse plane at the level of pulmonary artery bifurcation were compared. Additionally, frequency power distribution and dynamic time warp distance were calculated for these acquisitions. To further validate the adequate temporal resolution requirement, patients with S2 PC-CMR in the same acquisition plane were added in frequency power distribution analysis. RESULTS: Twenty-eight patients (25 males; 15.9 ± 1.9 years; body surface area (BSA) 1.7 ± 0.2 m2; heart rate 81 ± 16 bpm) underwent all five PC-CMR acquisitions during the study period. An additional 22 patients (16 males; 17.5 ± 7.7 years; BSA 1.6 ± 0.5 m2; heart rate 91 ± 16 bpm) were included for frequency power spectrum analysis. As expected, scan time decreased with increasing C-SENSE acceleration factor = 3 (37.5 ± 6.5 s, 26.4 ± 7.6%), 4 (28.1 ± 4.9 s, 44.7 ± 5.6%), 5 (21.6 ± 3.6 s, 57.6 ± 4.4%), and 6 (19.1 ± 3.2 s, 62.3 ± 4.2%) relative to SENSE = 2 (51.3 ± 10.1 s) PC-CMR acquisition. Mean peak velocity, net flow, and cardiac output were comparable (p > 0.87) between the five PC-CMR acquisitions with mean differences less than < 4%, < 2%, and < 3% respectively. All individual blood vessels showed a non-significant dependence of difference in fmax99 (< 4 Hz, p > 0.2), and dynamic time warp distance (p > 0.3) on the C-SENSE acceleration factor used. There was a strongly correlated (r = 0.74) increase in fmax99 (10.5 ± 2.2, range: 7.1-16.4 Hz) with increasing heart rate. The computed minimum required cardiac phase number was 15 ± 2.0 (range: 11-20) over the heart rate of 86 ± 15 bpm (range: 58-113 bpm). CONCLUSIONS: Stroke volume, cardiac output, and mean peak velocity measurements using PC-CMR with C-SENSE of up to 6 agree with measurements by standard of care PC-CMR with SENSE = 2 and resulted in up to a 65% reduction in acquisition time. Adequate temporal sampling can be ensured by acquiring 20 cardiac phases throughout the entire cardiac cycle over a wide range of pediatric and young adult heart rates.

Assessment of superior vena cava flow and cardiac output in different patterns of patent ductus arteriosus shunt.

BACKGROUND: Despite the widespread use of superior vena cava (SVC) flow as a marker of systemic blood flow from the upper body, no previous studies have systematically evaluated the correlation between SVC flow and other echocardiography measures of systemic blood flow in the context of different patterns of patent ductus arteriosus (PDA) shunt direction METHODS: A retrospective cohort study of preterm infants (< 30 weeks, < 21 days of life) who underwent comprehensive targeted neonatal echocardiography (TnECHO) was performed. Patients were categorized as follows: (i) Hemodynamically significant left-to-right shunt; (ii): Bidirectional shunt; (iii) No PDA or insignificant shunt. SVC flow, as measured by two distinct methods, was compared to left and right ventricular outputs (LVO and RVO). Intra- and inter-observer reliability testing was performed RESULTS: In total, 45 patients were included (15 in each group) with a median [IQR] weight of 720 [539, 917] grams at the time of assessment. SVC dimensions and flow measurements were not different between the groups, although patients with left-to-right shunt had higher LVO/RVO ratio. SVC flow, as estimated using the modified method, had a strong correlation with LVO (r = .63, p = 0.012) and RVO (r = .635, p = 0.011) in patients with no PDA. Inter- and intra-observer reliability were both stronger for LVO and RVO when compared to SVC flow measurements CONCLUSION: SVC flow was comparable across all three groups irrespective of higher LVO and LVO/RVO ratio in patients with left-to-right shunts. This may reflect poor measurement reliability or compensation for left-to-right ductal shunt by increased LVO to maintain systemic perfusion.

Dynamic assessment of the central vein throughout the cardiac cycle in adults with no right heart disease by cardiac CT.

PURPOSE: The aim of this study was to investigate the effect of the cardiac cycle on the vena cava and determine the phase of measuring maximum diameters. METHODS: A total of 152 patients who underwent cardiac computed tomography (CT) were included. Patients' basic information was collected. The major axis, minor axis, and cross-sectional area (CSA) of the vena cava in 10 phases reconstructed at 10% step from 5% to 95% R-R interval were measured in four planes (SVC1 layer: the bifurcation of the pulmonary artery; SVC2 layer: the superior vena cava (SVC) into the right atrium; IVC1 layer: the intersection of the inferior vena cava (IVC) and the right atrium; IVC2 layer: the IVC into the anterior hepatic plane). The difference in vena cava diameters between cardiac cycles was determined using the linear mixed model. RESULTS: The variations in diameter and CSA of the SVC in cardiac cycles were statistically significant (p < 0.05), while those of the suprahepatic IVC were not. In the SVC1 layer, the maximum value of the SVC major and minor axes was observed in 85% and 45% phases, respectively, while that in the SVC2 layer was observed in 45% phases. The maximum SVC diameters in the SVC1 and SVC2 layers were 19.48 ± 2.57 mm and 17.43 ± 3.09 mm, respectively. The SVC and IVC diameters and CSA were positively correlated with the body surface area in the linear mixed model. CONCLUSION: The maximum SVC diameter and CSA were mostly observed in 45% phase, which provides a reference for selecting the best phase to measure the abnormality of vena cava diameter in the future.

The impact of compliance on Stage 2 uni-ventricular heart circulation: An experimental assessment of the Bidirectional Glenn.

The Bidirectional Glenn (BDG) or cavopulmonary connection is typically undertaken to volume unload the single ventricle in an effort to preserve ventricular and atrioventricular valve function. The geometry of this surgical palliation has been shown to influence the fluid energy loss as well as the distribution of flow that enters through the superior vena cava. In-vitro and in-silico studies to date have been performed on rigid wall models, while this investigation looks at the impact of flexible thin walled models versus rigid walls. Rigid and compliant models of two patient-specific Glenn geometries were fabricated and tested under various flow conditions, within a biosimulator capable of replicating patient specific flow conditions. It was found that the compliant models exhibit greater levels of energy loss compared to the rigid models. Along with these findings greater levels of turbulence was found in both compliant models compared to their rigid counterparts under ultrasound examinations. This shows that vessel compliance has a significant impact on the hemodynamics within hypoplastic left heart syndrome.

Superior vena cava flow: Role, assessment and controversies in the management of perinatal perfusion.

The superior vena cava (SVC) is a large vein responsible for the venous return of blood from structures located superior to the diaphragm. The flow in the SVC can be assessed with Doppler ultrasound and can be used as a proxy for cerebral perfusion. Early clinical research studies showed that low SVC flow, particularly if for a prolonged period, was associated with short term morbidity such as intraventricular hemorrhage, mortality, and poorer neurodevelopmental outcomes. However, these findings have not been consistently reported in more recent studies, and the role of SVC flow in early management and as a predictor of poor long-term neurodevelopment has been questioned. This paper provides an overview of SVC assessment, the expected range of findings, and reviews the role of SVC flow as a diagnostic and monitoring tool for the assessment of perinatal perfusion.

Overlooked guide wire: a multicomplicated Swiss Cheese Model example. Analysis of a case and review of the literature.

Objectives: Central venous catheter (CVC) implementation is now usual in emergency department. The most common complications are misplacement, bleeding, pleural perforation, thrombosis and sepsis. Forgetting a guide wire in the patient's body after catheterization is an underestimated complication of this procedure; only 76 cases are described. Even if the majority of patients remained asymptomatic, severe complications can happened even years later. This article's aim is to identify the sequence of elements that led to the event occurrence and to suggest recommendations of good practice to minimize complications related to central catheter placement.Method: After reviewing all the complications related to central venous catheterization and their frequencies, we analyse from a case report and a review of the literature the sequence of elements that led to the medical error. We use an Ishikawa diagram to show our results and the links between them.Results: Our Ishikawa diagram shows that material, human resources, procedural and radiological involvement factors are the main elements on which we can act to reduce the complications rate after central venous catheterization. We advocate for the establishment of standardized procedures before, during and after the technical gesture.Conclusions: Because of human nature, errors will always be possible when taking care of a patient. However, we propose good practice recommendations to avoid the repetition of a forgetting guide wire after central venous catheterization.

Real-time magnetic resonance imaging-guided cryoablation of the pulmonary veins with acute freeze-zone and chronic lesion assessment.

AIMS: The goals of this study were to develop a method that combines cryoablation with real-time magnetic resonance imaging (MRI) guidance for pulmonary vein isolation (PVI) and to further quantify the lesion formation by imaging both acute and chronic cryolesions. METHODS AND RESULTS: Investigational MRI-compatible cryoablation devices were created by modifying cryoballoons and cryocatheters. These devices were used in canines (n = 8) and a complete series of lesions (PVI: n = 5, superior vena cava: n = 4, focal: n = 13) were made under real-time MRI guidance. Late gadolinium enhancement (LGE) magnetic resonance imaging was acquired at acute and chronic time points. Late gadolinium enhancement magnetic resonance imagings show a significant amount of acute tissue injury immediately following cryoablation which subsides over time. In the pulmonary veins, scar covered 100% of the perimeter of the ostium of the veins acutely, which subsided to 95.6 ± 4.3% after 3 months. Focal point lesions showed significantly larger acute enhancement volumes compared to the volumes estimated from gross pathology measurements (0.4392 ± 0.28 cm3 vs. 0.1657 ± 0.08 cm3, P = 0.0043). Additionally, our results with focal point ablations indicate that freeze-zone formation reached a maximum area after 120 s. CONCLUSION: This study reports on the development of an MRI-based cryoablation system and shows that with acute cryolesions there is a large area of reversible injury. Real-time MRI provides the ability to visualize the freeze-zone formation during the freeze cycle and for focal lesions reaches a maximum after 120 s suggesting that for maximizing lesion size 120 s might be the lower limit for dosing duration.

The role of Neonatologist Performed Echocardiography in the assessment and management of neonatal shock.

One of the major challenges of neonatal intensive care is the early detection and management of circulatory failure. Routine clinical assessment of the hemodynamic status of newborn infants is subjective and inaccurate, emphasizing the need for objective monitoring tools. An overview will be provided about the use of neonatologist-performed echocardiography (NPE) to assess cardiovascular compromise and guide hemodynamic management. Different techniques of central blood flow measurement, such as left and right ventricular output, superior vena cava flow, and descending aortic flow are reviewed focusing on methodology, validation, and available reference values. Recommendations are provided for individualized hemodynamic management guided by NPE.

Two- and three-dimensional transthoracic echocardiographic assessment of superior vena cava, crista terminalis, and right atrial appendage using the right parasternal approach.

BACKGROUND: The noninvasive assessment of superior vena cava (SVC), crista terminalis (CT), and the right atrial appendage (RAA) has clinical implications in determining the right atrium (RA) pressure in adult patients in whom the inferior vena cava cannot be imaged, in planning electrophysiological procedures and for evaluation of thrombi in RA/RAA. It is difficult to image these structures using standard two-dimensional transthoracic echocardiography (2DTTE), but the right parasternal approach has shown promise in the very few studies published so far. AIM: The aim of this study was to show the feasibility of this approach and its usefulness in qualitative and quantitative assessments of these structures by both 2D and three (3D) TTE in patients with and without known cardiac pathologies. MATERIAL AND METHODS: The study consisted of 38 adult patients, 17 of whom had cardiac pathologies (Group 1) while the remainder (Group 2) had no evidence of heart disease clinically or by echocardiography. RESULTS AND CONCLUSION: Both SVC and RAA could be imaged by 2DTTE and 3DTTE in 53% of 40 patients (two separate groups of 20 consecutive patients) studied demonstrating the technical feasibility of this approach. SVC size and collapsibility, CT and RAA size, and RAA fractional shortening were evaluated in both groups by both 2D and 3DTTE. 3DTTE provided incremental value over 2DTTE by its ability to view en face the SVC in short axis and the base of RAA and RAA volumes resulting in more comprehensive assessment of their size and function.

The diagnostic value of a single measurement of superior vena cava flow in the first 24 h of life in very preterm infants.

Low superior vena cava (SVC) flow has been associated with intraventricular haemorrhage (IVH) in very preterm infants. We studied the diagnostic value of a single measurement of SVC flow within the first 24 h of life in very preterm infants and its association with occurrence or extension of IVH in a setting of limited availability of neonatal echocardiography. Preterm infants who were born at less than 30 weeks gestation and who had an echocardiogram within 24 h after birth were eligible. Baseline, clinical and ultrasound data were collected. A total of 165 preterm infants were included. Low SVC flow (<41 ml/kg/min) occurred in six infants and was associated with severe IVH and extension of IVH, although this was not significant after adjusting for confounders. The only independently associated variable with low SVC flow was admission temperature (odds ratio 0.27, p = 0.001). A review of SVC flow values shows that these are higher now than initially reported. This study does not show an association of low SVC flow and severe IVH or extension of IVH after adjusting for confounders as a single measurement of SVC flow did not add any diagnostic value in this cohort. Thus, the exact role of SVC flow measurements in the circulatory assessment of preterm infants remains to be elucidated. However, admission temperature may have an effect on systemic blood flow in very preterm infants.

Comparison between transthoracic echocardiography and cardiac magnetic resonance imaging in patients status post atrial switch procedure.

OBJECTIVES: This study compares image quality, cost, right ventricular ejection fraction analysis, and baffle visualization between transthoracic echocardiography and cardiac magnetic resonance imaging in those status post atrial switch for transposition of the great arteries. BACKGROUND: This population requires imaging for serial evaluations. Transthoracic echocardiography is often first line but has drawbacks, many of which are addressed by cardiac magnetic resonance imaging. METHODS: Twelve patients (mean age 25 years) with relatively concurrent (mean 157 days) studies were included. Three separate echocardiography and magnetic resonance imaging physicians independently analyzed baffles, image quality, and right ventricular ejection fractions. Institutional and Medicaid charges were compared. RESULTS: For right ventricular ejection fraction, echocardiography (36.1%) underestimated cardiac magnetic resonance imaging (47.8%, P = .002). Image quality for transthoracic echocardiography was significantly rated lower than cardiac magnetic resonance imaging (P = .002). Baffles were better seen in cardiac magnetic resonance imaging (transthoracic echocardiography vs. cardiac magnetic resonance imaging: superior vena cava 86% vs. 100% [P = .063]; inferior vena cava 33% vs. 97% [P = .002]; pulmonary vein 92% vs. 100% [P = .250]). Comparing hospital charges and Medicaid reimbursement, transthoracic echocardiography respectively costs 18% and 38% less than cardiac magnetic resonance imaging. CONCLUSIONS: In conclusion, transthoracic echocardiography underestimated right ventricular ejection fraction compared to cardiac magnetic resonance imaging. Cardiac magnetic resonance imaging had consistently higher image quality and better visualization of the baffles. Cost differences are minimal. We propose that cardiac magnetic resonance imaging be considered first line for imaging in certain patients' status post atrial switch procedure.

Left circumflex coronary artery fistula to the superior vena cava: assessment of the exact anatomy by multidetector CT.

A 62-year-old woman with mild dyspnea on exertion underwent coronary angiography. A large fistula of the left circumflex artery was found but the exit site of this unusual anomaly could not be established. Contrast-enhanced multidetector computed tomography of the coronary arteries was performed which allowed clear identification of the drainage of the fistula into the superior vena cava.

Comparison of enhancement, image quality, cost, and adverse reactions using 2 different contrast medium concentrations for routine chest CT on 16-slice MDCT.

OBJECTIVE: To evaluate the degree of enhancement and image quality of chest computed tomographic (CT) examinations on 16-slice multidetector CT using low-concentration [300 milligrams of iodine per milliliter (mg I/mL)] and high-concentration (370 mg I/mL) contrast media; to assess the impact on cost and adverse reactions of the use of high-iodine concentration contrast medium. MATERIALS AND METHODS: A total of 100 patients scheduled for routine chest CT examinations were administered nonionic contrast medium of 2 strengths: low-iodine concentration contrast medium (300 mg I/mL) [group A: n = 50; male-female ratio, 28:22; mean age, 58.4 years] and high-iodine concentration contrast medium (370 mg I/mL) (group B: n = 50; male-female ratio, 18:32; mean age, 57.6 years) with a constant amount of iodine (400 mg) injected per kilogram of body weight. Contrast media were injected using a dual injector at 2.5 mL/s followed by a 30-mL saline at 2.5 mL/s. The degree of enhancement was quantified by measuring Hounsfield unit values in different arteries and veins and was also rated on a 5-point scale for qualitative assessment. We also evaluated perivenous contrast-related artifacts. The data were compared using Mann-Whitney U test for both qualitative and quantitative enhancement ratings. A value of less than 0.05 was considered statistically significant. The value was adjusted using Bonferroni correction for statistical significance when multiple comparisons were performed. The difference in cost and the incidence of adverse reactions in both groups were calculated. RESULTS: The mean enhancement values in group B were significantly greater (P < 0.05) than those in group A. The mean Hounsfield units and standard deviation in groups A and B were aorta = 153 +/- 4, 216 +/- 20; pulmonary artery = 147 +/- 10, 208 +/- 20; superior vena cava = 155 +/- 27, 299 +/- 72; and pulmonary vein = 134 +/- 10, 215 +/- 30, respectively. The mean enhancement on a 5-point scale was greater in group B (4.2) than in group A (3.3) (P < 0.01). No significant difference between groups in perivenous artifacts was seen. Up to 5.5% savings in cost resulted from the use of a higher concentration of iodine, with no increase in adverse reactions. CONCLUSIONS: Use of higher-concentration contrast media provides a higher degree of contrast enhancement and image quality for a routine chest CT on a 16-slice multidetector CT. It also contributes to considerable cost savings with no increased risk of adverse reactions compared with low-concentration contrast media.

Assessment of in-stent stenosis in small children with congenital heart disease using multi-detector computed tomography: a validation study.

OBJECTIVES: Our purpose was to investigate the diagnostic reliability of multi-detector computed tomography (MDCT) in assessing in-stent stenosis compared to digital angiography (DA) in small children. BACKGROUND: Little is known about the feasibility of using MDCT to assess stents placed to treat children with congenital heart disease (CHD). METHODS: Twenty-two children (median age [range], 2(3/4) [(1/2) to 12] years) with 42 transcatheter placed stents (median diameter: 7.2 [3.4-16.3] mm) in the pulmonary arteries (n = 36), aorta (2), PDA (1), and SVC (3) underwent both MDCT and DA due to suspected hemodynamic problems. RESULTS: Independent "blinded" observers were able to measure stent and minimal luminal diameters in 115 out of 124 (93%) stent segments on MDCT and DA. The interobserver variability was low (mean difference: 0.5, SD 0.8 mm) with high correlation (r = 0.97; P < .0001). The percent stenosis by MDCT correlated well with DA (r = 0.89, P < .0001; mean error 2.7, SD 10.4%). For all grades of stenosis, the sensitivity and specificity for MDCT were 58% and 97%, respectively. At a threshold of approximately > or =20% stenosis sensitivity became >98%. All stent associated complications [fracture (4), vascular narrowings (11)] were diagnosed by MDCT. As the stent diameter increased, there was significantly reduced variability between MDCT and DA for in-stent stenosis (P < .0001). CONCLUSION: In small children, MDCT is a feasible and promising method for assessing stent associated complications in the treatment of CHD. Cardiac surgeons and interventional cardiologists might rely on this imaging modality to plan specific interventions more precisely and to assess the results upon follow up.

Pediatric superior vena cava syndrome: assessment at low radiation dose 64-slice CT angiography.

We report a case of an 8-year-old boy with a history of aortopexy for aortic compression and multiple venous thrombosis. A 64-slice multidetector-row computed tomography examination was performed to evaluate the cause of esophageal varices and the extent of previously reported thrombi. Despite extremely low radiation dose settings, the 64-slice computed tomography angiography was fully diagnostic and showed discontinuity of the superior vena cava and brachiocephalic veins. In addition, the azygous system and large collateral vessels across the anterior, medial, and posterior mediastinum and chest wall were observed. This case shows that in pediatric patients complicated vascular pathology can reliably be assessed and radiation exposure can be safely minimized.

Live three-dimensional transthoracic echocardiographic assessment of thrombus in the innominate veins and superior vena cava utilizing right parasternal and supraclavicular approaches.

We report the usefulness of right parasternal and supraclavicular live three-dimensional transthoracic echocardiography in the delineation and follow-up of a thrombus involving a catheter placed in superior vena cava for dialysis in an adult patient with chronic renal disease.