Cardiac manifestations and outcomes of COVID-19 vaccine-associated myocarditis in the young in the USA: longitudinal results from the Myocarditis After COVID Vaccination (MACiV) multicenter study.

Background: We aimed to study the clinical characteristics, myocardial injury, and longitudinal outcomes of COVID-19 vaccine-associated myocarditis (C-VAM). Methods: In this longitudinal retrospective observational cohort multicenter study across 38 hospitals in the United States, 333 patients with C-VAM were compared with 100 patients with multisystem inflammatory syndrome in children (MIS-C). We included patients ≤30 years of age with a clinical diagnosis of acute myocarditis after COVID-19 vaccination based on clinical presentation, abnormal biomarkers and/or cardiovascular imaging findings. Demographics, past medical history, hospital course, biochemistry results, cardiovascular imaging, and follow-up information from April 2021 to November 2022 were collected. The primary outcome was presence of myocardial injury as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging. Findings: Patients with C-VAM were predominantly white (67%) adolescent males (91%, 15.7 ± 2.8 years). Their initial clinical course was more likely to be mild (80% vs. 23%, p < 0.001) and cardiac dysfunction was less common (17% vs. 68%, p < 0.0001), compared to MIS-C. In contrast, LGE on CMR was more prevalent in C-VAM (82% vs. 16%, p < 0.001). The probability of LGE was higher in males (OR 3.28 [95% CI: 0.99, 10.6, p = 0.052]), in older patients (>15 years, OR 2.74 [95% CI: 1.28, 5.83, p = 0.009]) and when C-VAM occurred after the first or second dose as compared to the third dose of mRNA vaccine. Mid-term clinical outcomes of C-VAM at a median follow-up of 178 days (IQR 114-285 days) were reassuring. No cardiac deaths or heart transplantations were reported until the time of submission of this report. LGE persisted in 60% of the patients at follow up. Interpretation: Myocardial injury at initial presentation and its persistence at follow up, despite a mild initial course and favorable mid-term clinical outcome, warrants continued clinical surveillance and long-term studies in affected patients with C-VAM. Funding: The U.S. Food and Drug Administration.

Evaluation of left ventricular function and volume by two-dimensional echocardiography in a pediatric population: Correlation with cardiac magnetic resonance imaging.

Background: Echocardiographic quantification of left ventricular (LV) volume and ejection fraction (EF) is widely used in the pediatric population. However, there is no consensus on the most accurate method of quantifying ventricular volumes and systolic function. Purpose: The purpose of this study is to compare two commonly used echocardiographic methods for the evaluation of LV volume and quantification of EF, the five-sixth area-length (5/6 AL) and the modified biplane Simpson (BS), to cardiac magnetic resonance (CMR) imaging in children. Methods: CMR studies were paired with echocardiograms and retrospectively analyzed in children 18 years of age and younger. Studies performed more than 3 months between modalities, patients with congenital heart disease, and patients who had changes in medication regimen between corresponding CMR and echocardiograms were excluded. LV volumes and EF were calculated using the 5/6 AL and BS methods and compared to volumes and EF measured on corresponding CMR studies. Subgroup analyses were conducted based on LV function, pathology, and weight. Results: We retrospectively analyzed 53 CMR and corresponding echocardiogram studies (23 studies for myocarditis and 30 studies for cardiomyopathy) in 46 patients. LVEF derived by both echocardiographic methods showed a good correlation to CMR (5/6 AL r = 0.85 and BS r = 0.82). However, both echocardiographic methods overestimated LVEF and underestimated LV volumes when compared to CMR. Conclusion: Left ventricular volumes and EF, as measured by echocardiography, correlate well with CMR measurements. Echocardiography underestimates LV systolic and diastolic volumes and overestimates LVEF. While echocardiography is a good surrogate for estimating LVEF, CMR should be considered in patients for whom accurate measurements are needed for critical clinical decision-making.

Correlation of MRI premature ventricular contraction activation pattern in bigeminy with electrophysiology study-confirmed site of origin.

Although PVCs commonly lead to degraded cine cardiac MRI (CMR), patients with PVCs may have relatively sharp cine images of both normal and ectopic beats ("double beats") when the rhythm during CMR is ventricular bigeminy, and only one beat of the pair is detected for gating. MRI methods for directly imaging premature ventricular contractions (PVCs) are not yet widely available. Localization of PVC site of origin with images may be helpful in planning ablations. The contraction pattern of the PVCs in bigeminy provides a "natural experiment" for investigating the potential utility of PVC imaging for localization. The purpose of this study was to evaluate the correlation of the visually assessed site of the initial contraction of the ectopic beats with the site of origin found by electroanatomic mapping. Images from 7 of 86 consecutive patients who underwent CMR prior to PVC ablation were found to include clear cine images of bigeminy. The visually apparent site of origin of the ectopic contraction was determined by three experienced, blinded CMR readers and correlated with each other, and with PVC site of origin determined by 3D electroanatomic mapping during catheter ablation. Blinded ascertainment of visually apparent initial contraction pattern for PVC localization was within 2 wall segments of PVC origin by 3D electroanatomic mapping 76% of the time. Our data from patients with PVCs with clear images of the ectopic beats when in bigeminy provide proof-of-concept that CMR ectopic beat contraction patterns analysis may provide a novel method for localizing PVC origin prior to ablation procedures. Direct imaging of PVCs with use of newer cardiac imaging methods, even without the presence of bigeminy, may thus provide valuable data for procedural planning.

Preservation of Antegrade Pulmonary Blood Flow in Kawashima Procedure With Prior Right Ventricular Outflow Tract Stent.

Surgical management of single ventricle with interrupted inferior vena cava and azygos continuation typically requires a Kawashima procedure with subsequent completion of Fontan. However, this group is at risk of development of pulmonary arteriovenous malformations. Evidence suggests preservation of hepatic venous flow into the pulmonary circulation can potentially delay this development. We hereby describe a method of preserving antegrade pulmonary blood flow during the Kawashima procedure in the setting of prior right ventricular outflow tract stents.

Surgical Management of Giant Intrapericardial Teratoma Encasing the Coronary Artery.

Intrapericardial teratomas are rare, predominantly benign tumors that warrant surgical resection in the neonatal period because of their potential detrimental effects on the cardiorespiratory system. Surgical resection can be a challenge when the tumor encases and obscures a coronary artery. Adherence to certain operative principles is necessary to achieve successful outcomes.

Strain in children with MIS-C and acute COVID-19.

Context: Cardiac injury has been described in both acute COVID-19 and the multisystem inflammatory syndrome in children (MIS-C). Echocardiographic strain has been shown to be a sensitive measure of systolic function. Aims: We sought to describe strain findings in both the groups on initial presentation and follow-up. Settings and Design: A retrospective study analyzing echocardiograms of all patients presenting with acute COVID-19 infection and MIS-C at our institution between March 2020 and December 2020 was performed. Subjects and Methods: TOMTEC software was used for strain analysis in both the study groups (COVID-19 and MIS-C) and age-matched healthy controls. Strain was correlated with LV ejection fraction (EF) and serum troponin levels. Results: Forty-five patients (34 - MIS-C and 11 - COVID-19) met the inclusion criteria. There was a statistically significant decrease in LV longitudinal strain (P < 0.001), LV circumferential strain (P < 0.001), and left atrial strain (P = 0.014) in the MIS-C group when compared to the control group. There was a statistically significant decrease in LV longitudinal strain (P = 0.028) in the acute COVID-19 group. All patients with abnormal left ventricular EF (LVEF) had abnormal strain. However, 14 (41%) patients in the MIS-C group and 3 (27%) in the acute COVID-19 group had preserved LVEF but abnormal strain. There was a significant correlation with LV longitudinal strain (P = 0.005) and LVEF (P = 0.002) and troponin in patients with MIS-C. Abnormal strain persisted in one-third of patients in the MIS-C and acute COVID-19 groups on outpatient follow-up. Conclusions: Patients with MIS-C and acute COVID-19 can develop myocardial dysfunction as seen by abnormal strain. LV longitudinal strain correlates with cardiac injury as measured by serum troponin in patients with MIS-C. Strain may provide an additional tool in detecting subtle myocardial dysfunction. It can be routinely employed at diagnosis and at follow-up evaluation of these patients.

Periscopic technique in Norwood operation is associated with better preservation of early ventricular function.

OBJECTIVE: Although the right ventricle (RV) to pulmonary artery conduit in stage 1 Norwood operation results in improved interstage survival, the long-term effects of the ventriculotomy used in the traditional technique remain a concern. The periscopic technique (PT) of RV to pulmonary artery conduit placement has been described as an alternative technique to minimize RV injury. A retrospective study was performed to compare the effects of traditional technique and PT on ventricular function following Norwood operation. METHODS: A retrospective study of all patients who underwent Norwood operation from 2012 to 2019 was performed. Patients with baseline RV dysfunction and significant tricuspid valve regurgitation were excluded. Prestage 2 echocardiograms were reviewed by a blinded experienced imager for quantification of RV function (sinus and infundibular RV fractional area change) as well as for regional conduit site wall dysfunction (normal or abnormal, including hypokinesia, akinesia, or dyskinesia). Wilcoxon rank-sum tests were used to assess differences in RV infundibular and RV sinus ejection fraction and the Fisher exact test was used to assess differences in regional wall dysfunction. RESULTS: Twenty-two patients met inclusion criteria. Eight underwent traditional technique and 14 underwent PT. Median infundibular RV fractional area change was 49% and 37% (P = .02) and sinus RV fractional area change was 50% and 41% for PT and traditional technique (P = .007) respectively. Similarly qualitative regional RV wall function was better preserved in PT (P = .002). CONCLUSIONS: The PT for RV to pulmonary artery conduit in Norwood operation results in better preservation of early RV global and regional systolic function. Whether or not this benefit translates to improved clinical outcome still needs to be studied.

Diagnosis of anomalous origin of the right subclavian artery from the right pulmonary artery in a patient with D-transposition of the great arteries utilizing transthoracic echocardiography.

Diagnosis of anomalous origin of the right subclavian artery (AORSA) from the right pulmonary artery (RPA) is usually made using CT, MRI, or invasive angiography. We report a patient diagnosed using transthoracic echocardiography (TTE). A newborn girl prenatally known to have d-TGA presented with cyanosis sparing the right hemithorax and arm. Oxygen saturations on the right hand were persistently higher than on the right ear and other extremities. Repeat TTE using a modified echocardiographic imaging plane allowed for full visualization of the entire subclavian artery course, revealing AORSA from RPA. We discuss further the approach to echocardiographic diagnosis and surgical implications.

Cardiac involvement in a pediatric patient with COVID-19: Looking beyond the nonspecific global cardiac injury.

We report a case of a 17-year-old healthy male presenting with multisystem hyperinflammatory shock temporally associated with COVID-19. Cardiac involvement was suspected based on evidence of significant cardiac injury (elevated cardiac biomarkers, electrocardiographic and echocardiographic abnormalities). Cardiac magnetic resonance imaging was performed demonstrating global biventricular systolic dysfunction, as well as a small area of T2 hyperintensity and mid-wall late gadolinium enhancement. This case discusses the varied cardiac involvement in pediatric patients with COVID-19 infection and highlights that cardiac injury is not just limited to hyperinflammatory syndrome related global dysfunction but a more focal myocarditis can also be seen.

Inferior Right Ventricular Wall Thickness by Echocardiogram: A Novel Method of Assessing Hypertrophy in Neonates and Infants.

An established echocardiographic (echo) standard for assessing the newborn right ventricle (RV) for hypertrophy has not been thoroughly developed. This is partially due to the RV's complex architecture, which makes quantification of RV mass by echo difficult. Here, we retrospectively evaluate the thickness of the inferior RV wall (iRVWT) by echo in neonates and infants with normal cardiopulmonary physiology. Inferior RVWT was defined at the medial portion of the inferior wall of the RV at the mid-ventricular level, collected from a subxiphoid, short axis view. iRVWT was indexed to body surface area (BSA) to the 0.5 power and normalized to iLVWT to explore the best normalization method. Ninety-eight neonates and 32 infants were included in the final analysis. Mean age for neonates and infants was 2 days and 59 days, respectively. Mean ± SD for neonate and infant end-diastole iRVWT was 2.17 ± 0.35 mm and 1.79 ± 0.28 mm, respectively. There was no residual relationship between the index iRVWT and BSA (r = 0.03, p = NS). In the infant cohort, the iRVWT was significantly lower and iLVWT was significantly higher compared to neonate, consistent with known physiologic changes of RV and LV mass. Thus, iRVWT may serve as a reliable and accurate proxy for RV mass and the parameter warrants further evaluation.

"Chorea": A Unique Presentation of Left Atrial Myxoma in a Pediatric Patient.

We report an unusual presentation of a large left atrial myxoma in an eight-year-old girl who presented with the sudden onset of chorea. This case illustrates the fact that the presentation of chorea in nonendemic areas for rheumatic fever should raise suspicion for a myxoma. The chorea resolved soon after removal of the myxoma, supporting the hypothesis of an immune-mediated mechanism, or manifestation of paraneoplastic syndrome secondary to the myxoma.

Unusual Cause of Severe Tricuspid Regurgitation: Tricuspid Leaflet Annular Tear Following Remote Motor Vehicle Accident.

Tricuspid regurgitation (TR) is an uncommon and underdiagnosed complication of blunt chest trauma. Typical mechanisms include torn chordae, papillary muscle rupture, and radial leaflet tear. We describe an unusual case of traumatic TR due to circumferential avulsion of the anterior tricuspid leaflet from the tricuspid annulus and the crucial role of multimodality imaging in its diagnosis and treatment. (Level of Difficulty: Intermediate.).

Impaired myocardial deformation and ventricular vascular coupling in obese adolescents with dysglycemia.

BACKGROUND: It is unknown that dysglycemia in obese adolescents has effects on myocardial deformation that are more pronounced when compared to obesity alone. We hypothesized that obesity associated abnormal glucose tolerance (dysglycemia) would have adverse effects on two-dimensional speckle tracking echocardiography derived longitudinal, radial and circumferential strain (LS, RS, CS) compared to age and gender lean controls. We also examined if changes in deformation would be reflected in abnormal ventricular vascular coupling indices (VVI). METHODS: In a prospective cross-sectional design 39 obese adolescents (15.9 ± 1.7 years; 101.5 ± 39 kg; female - 58%) were compared to age and gender matched lean controls (15.7 ± 1.8 yrs, 60 ± 12.8 kg). Based on results from an oral glucose tolerance test (OGTT), obese adolescents were categorized as obese normoglycemic (ONG, n = 25) or obese dysglycemic (ODG, n = 14). Left ventricular (LV) global and average LS, CS, RS and strain rate were measured. LV ejection fraction and mass index were measured and VVI approximated as ratio of arterial elasticity (Ea) and end-systolic elastance (Ees). RESULTS: Adolescents with ODG had significantly (P = 0.005) impaired global LS (- 20.98% ± 2.8%) compared to controls (- 23.01% ± 2.3%). A similar (P = 0.0027) reduction was observed in average LS for adolescents with ODG (18.87% ± 2.5%) compared to controls (20.49% ± 2%). Global CS was also decreased (P = 0.03) in ODG (- 23.95%) compared to ONG (- 25.80). A similar trend was observed in average CS after multivariate regression for BMI and blood pressure. CS correlated with HbA1c in both groups (P = 0.05). VVI had a negative correlation with both LS (r = - 0.4, P = 0.025) and CS rate (r = - 0.36, P = 0.04). CONCLUSIONS: Myocardial strain and strain rate were significantly altered in obese adolescents. Unfavorable subclinical reductions in global and average CS were more pronounced in adolescents with dysglycemia compared to obese adolescents with normoglycemia and controls. These data indicate progressive worsening of subendocardial function across the spectrum of glucose tolerance. Strain rate was predictive of VVI in obese adolescents, suggesting strain rate may be a sensitive marker for cardiac remodeling in abnormal glucose homeostasis states.

The Early "Unnatural" History Following Surgical Repair of Ventricular Septal Defects.

INTRODUCTION: Surgical outcomes for simple ventricular septal defects (VSD) have been excellent in the past three decades. For this project, the timing of resolution of left-sided dilation and mitral regurgitation (MR) following VSD repair was assessed. METHODS: Echocardiographic data surrounding surgery of 42 consecutive children who underwent surgical patch repair of a VSD were reviewed. The echocardiograms were reviewed up to a mean of 12 months post-operatively (range 9 - 14 months). Quantitative data indexed to body surface area including left atrial (LA) volume, mitral valve annulus diameter, and left ventricular end-diastolic dimension (LVEDD) was analyzed. RESULTS: The majority of our pre-surgical cohort had only trace (44%) or no MR (31%), with a small proportion having mild (16%) or moderate MR (9%). No patients had moderate or greater MR following repair at follow-up. The median mitral valve annular Z-score was 1.8 (SD 1.6; range: -1.2 to 4.1) pre-operatively, improving to a 0.6 (range: -1.7 to 2.4; p < 0.001) at follow-up. LA dilation was present in 70% of patients, with a median LA volume Z-score of 1.1 (range: -2.6 to 15.5), decreasing to 13% median Z-score -1.2 (range: -3.5 to 2.9; p < 0.001) at follow-up. LV dilation was present in 81% of pre-operative patients with a median LVEDD Z-score of 3.0 (range: -2.0 to 7.9). There was significant improvement in qualitative assessment of LV enlargement (25%) with a median LVEDD Z-score of 0.5 (range: -2.1 to 2.9; p < 0.001) at follow-up. Discharge echocardiogram was performed at a mean of 5.7 days (range: 3 - 12 days) following surgery. CONCLUSIONS: Normalization of LA, mitral valve annulus, and LV size occurred within the first three months in the majority of patients, with significant changes occurring within the first post-operative week following surgical repair for VSD.

Left Ventricular Mass Quantification by Two-Dimensional Echocardiography in a Pediatric Population: Correlation with Cardiac Magnetic Resonance Imaging.

Quantification of left ventricular (LV) mass by echocardiography has not been validated against the gold standard of cardiac magnetic resonance imaging (CMR) in the pediatric population. The purpose of this study was to compare LV mass by two-dimensional and conventional M-mode echocardiography versus CMR in children. Consecutive CMR studies were paired with echocardiograms and retrospectively analyzed in children age ≤ 16 years (3 days old to 16 years old). Studies performed > 3 months between modalities and single ventricle anatomy were excluded. Unindexed LV mass was calculated using M-mode, area-length (AL), and truncated ellipsoid (TE) methods via echocardiography, and compared to cine stack CMR images. There were 46 patients included in the study (both MRI and echocardiography). Good correlations were observed for LV mass measured by CMR and all echocardiographic methods: M-mode (R = 0.965), AL (R = 0.975), and TE (R = 0.975). There was a significant overestimation using TE echocardiography, by a mean of 10.5 g (95% confidence interval 5.7-15.2 g, p < 0.05). There was no significant over- or underestimation of LV mass observed by M-mode or AL echocardiographic measurements, with tight limits of agreement when compared to CMR (95% confidence interval - 5.2 to 4.4 g and - 1.5 to 6.7 g, respectively). Interobserver agreement was good for each of the echocardiographic measurements, but inferior with M-mode (ICC, 0.89) compared to two-dimensional methods (ICC, 0.97). Echocardiographic estimates of LV mass have good correlation with CMR in children. Performance comparison showed AL echocardiographic method provides the most accurate measurement of LV mass with the best reproducibility compared to other methods.