Mitral Annular Disjunction: An Under-Recognized Entity in Pediatrics.

Mitral annular disjunction (MAD) is a rare and under-recognized entity in the pediatric population. We present 2 cases of MAD in previously healthy pediatric patients and highlight clinical scenarios where MAD should be suspected.

Interstitial Fibrosis and Arrhythmic Mitral Valve Prolapse: Unravelling Sex-Based Differences.

Background: Interstitial fibrosis as quantified by cardiac magnetic resonance (CMR) has been demonstrated in arrhythmic mitral valve prolapse (MVP), a condition with known female predominance. However, prior studies included only MVP cases with significant mitral regurgitation (MR) or mitral annular disjunction (MAD). We sought to evaluate the association between interstitial fibrosis and complex ventricular ectopy (ComVE) in MVPs unselected for MAD or severe MR, and to investigate the contribution of sex to this association. Methods: We performed contrast CMR in consecutive individuals with MVP between 2020 and 2022. Extracellular volume fraction (ECV%), a surrogate marker for interstitial fibrosis, was quantified using T 1 mapping. Replacement fibrosis was assessed using late gadolinium enhancement (LGE). ComVE, defined as frequent premature ventricular contractions and/or non-sustained/sustained ventricular tachycardia (VT), was detected using ambulatory ECG monitoring. Results: We identified 59 MVP cases without severe MR (49% women, 80% with mild or less MR) and available ECV% measurement. Among these, 23 (39%) had ComVE, including a case of aborted ventricular fibrillation (VF) and one with sudden arrhythmic death, both females. Global ECV% was significantly greater in ComVE versus non-ComVE (31%[27-33] vs 27%[23-30], p=0.002). In MVP-ComVE, higher segmental ECV% was not limited to the inferolateral/inferior LV wall, but was also demonstrated in atypical segments including the anterior/anterolateral wall (p<0.05). The association between ComVE and ECV% was driven by female sex (32%[30-33] vs 28%[26-30], p=0.003 in females; 31%[25-33] vs 26%[23-30], p=0.22 in males). ECV% remained independently associated with an increased risk of ComVE, including VT/VF, after adjustment for cardiovascular risk factors, MAD, and LGE (p<0.01). Conclusion: In MVP without significant MR, interstitial fibrosis by CMR is associated with an increased risk of ComVE, suggesting a primary myopathic process. The stronger association between interstitial fibrosis and ComVE in females may explain why severe arrhythmic complications are more prevalent among women.

Criss-cross heart three-dimensional printed models in medical education: A multicenter study on their value as a supporting tool to conventional imaging.

The utility of three-dimensional (3D) printed models for medical education in complex congenital heart disease (CHD) is sparse and limited. The purpose of this study was to evaluate the utility of 3D printed models for medical education in criss-cross hearts covering a wide range of participants with different levels of knowledge and experience, from medical students, clinical fellows up to senior medical personnel. Study participants were enrolled from four dedicated imaging workshops developed between 2016 and 2019. The study design was a non-randomized cross-over study to evaluate 127 participants' level of understanding of the criss-cross heart anatomy. This was evaluated using the scores obtained following teaching with conventional images (echocardiography and magnetic resonance imaging) versus a 3D printed model learning approach. A significant improvement in anatomical knowledge of criss-cross heart anatomy was observed when comparing conventional imaging test scores to 3D printed model tests [76.9% (61.5%-87.8%) vs. 84.6% (76.9%-96.2%), P < 0.001]. The increase in the questionnaire marks was statistically significant across all academic groups (consultants in pediatric cardiology, fellows in pediatric cardiology, and medical students). Ninety-four percent (120) and 95.2% (121) of the participants agreed or strongly agreed, respectively, that 3D models helped them to better understand the medical images. Participants scored their overall satisfaction with the 3D printed models as 9.1 out of 10 points. In complex CHD such as criss-cross hearts, 3D printed replicas improve the understanding of cardiovascular anatomy. They enhanced the teaching experience especially when approaching medical students.

Myocarditis in children after COVID-19 vaccine.

Three healthy adolescents presented with myocarditis confirmed on cardiac magnetic resonance imaging after receiving Pfizer-BioNTech COVID-19 vaccine. All patients were hemodynamically stable and had good short-term outcomes. Long-term outcomes are yet to be determined. Larger studies are needed to determine whether an association between Pfizer-BioNTech COVID-19 vaccine and myocarditis exists.

COVID-19 Vaccination-Associated Myocarditis in Adolescents.

OBJECTIVES: In this study, we aimed to characterize the clinical presentation, short-term prognosis, and myocardial tissue changes as noted on cardiovascular magnetic resonance (CMR) or cardiac MRI in pediatric patients with coronavirus disease 2019 vaccination-associated myocarditis (C-VAM). METHODS: In this retrospective multicenter study across 16 US hospitals, patients <21 years of age with a diagnosis of C-VAM were included and compared with a cohort with multisystem inflammatory syndrome in children. Younger children with C-VAM were compared with older adolescents. RESULTS: Sixty-three patients with a mean age of 15.6 years were included; 92% were male. All had received a messenger RNA vaccine and, except for one, presented after the second dose. Four patients had significant dysrhythmia; 14% had mild left ventricular dysfunction on echocardiography, which resolved on discharge; 88% met the diagnostic CMR Lake Louise criteria for myocarditis. Myocardial injury as evidenced by late gadolinium enhancement on CMR was more prevalent in comparison with multisystem inflammatory syndrome in children. None of the patients required inotropic, mechanical, or circulatory support. There were no deaths. Follow-up data obtained in 86% of patients at a mean of 35 days revealed resolution of symptoms, arrhythmias, and ventricular dysfunction. CONCLUSIONS: Clinical characteristics and early outcomes are similar between the different pediatric age groups in C-VAM. The hospital course is mild, with quick clinical recovery and excellent short-term outcomes. Myocardial injury and edema are noted on CMR. Close follow-up and further studies are needed to understand the long-term implications and mechanism of these myocardial tissue changes.

Double-Outlet Right Ventricle, Pulmonary Atresia, and Discontinuous Branch Pulmonary Arteries Supplied by Bilateral Ducti.

We present a rare case of double-outlet right ventricle with pulmonary atresia and discontinuous branch pulmonary arteries supplied by bilateral ducti from a right aortic arch. To our knowledge, this is only the second documented case of double-outlet right ventricle with bilateral ducti. (Level of Difficulty: Advanced.).

Two-Dimensional Strain is more Precise than Conventional Measures of Left Ventricular Systolic Function in Pediatric Patients.

Ejection fraction (EF) and fractional shortening (FS) are standard methods of quantifying left ventricular (LV) systolic function. 2D global longitudinal strain (2D GLS) is a well-established, but underutilized method for LV function quantification. The aim of this study was to assess precision of GLS compared to EF & FS in pediatrics. Echocardiograms were prospectively analyzed by 2 blinded observers. FS, EF, and GLS were calculated following standard methods. Bland-Altman was applied to assess agreement. Intraclass correlation coefficient (ICC) was used to measure reliability. Coefficient of variation was used to demonstrate relative variability between methods. 103 pediatric echos were evaluated for inter-observer reproducibility, and 15 patients for intra-observer reproducibility. GLS had higher inter-observer agreement and reliability (bias 7%, 95% LOA - 3.4 to + 3.5, ICC 0.86 CI 0.80-0.90) compared to EF (bias 27%, 95% LOA - 18.9 to + 19.5; ICC 0.25 CI 0.07-0.43) and FS (bias 12%, 95% LOA - 11.9 to + 12.2; ICC 0.53 CI 0.38-0.66). GLS also had higher intra-observer agreement (bias 4%, 95% LOA - 3.6 to + 3.7; ICC 0.87 CI 0.66-0.96) compared to EF (bias 11%, 95% LOA - 14.9 to + 15.1; ICC 0.26 CI - 0.28-0.67) and FS (bias 12%, 95% LOA - 12.2 to + 12.5; ICC 0.38 CI - 0.15-0.74). GLS is a more precise method for quantifying LV function in pediatrics, with lower variability compared to EF and FS. GLS provides a more reliable evaluation of LV systolic function and should be utilized more widely in pediatrics.

Potts Shunt Improves Right Ventricular Function and Coupling With Pulmonary Circulation in Children With Suprasystemic Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension is a progressive disease with poor outcomes in children. Right ventricular (RV) function is the most important determinant of the prognosis. Novel application of Potts shunt between left pulmonary artery and descending aorta has been introduced in an attempt to improve the survival. However, the effect of Potts shunt creation on RV function, RV-PA coupling, and survival has not been studied. METHODS AND RESULTS: We evaluated the first 12 consecutive pediatric patients (9 male, median age 11.2 years and weight 32.8 kg) who underwent elective Potts shunt placement for suprasystemic pulmonary arterial hypertension between 2013 and 2017 with echocardiographic indices of RV function, RV work, RV-PA coupling, and pulmonary hemodynamics. Of 12 patients, 1 was excluded because of insufficient preshunt data, 2 died, 1 required lung transplant, and 8 survived for a median of 27 months postshunt. In survivors, WHO functional class significantly ( P=0.01) improved and the majority (5 of 8) came off pulmonary vasodilators at the most recent follow-up. Postshunt RV systolic function improved ( P=0.03), RV afterload decreased ( P <0.01), RV work decreased ( P=0.02), and RV-proximal PA coupling improved ( P<0.01). CONCLUSIONS: This proof of concept study shows that Potts shunt allows improvement in functional status and mid-term transplant-free survival in the majority of the recipients by improvement in RV systolic function and RV-PA coupling in children with suprasystemic pulmonary arterial hypertension.

Rare presentation of an atrial myxoma in an adolescent patient: a case report and literature review.

BACKGROUND: Cardiac tumors are uncommon in the pediatric population. When present, cardiac manifestations stem from the tumor causing inflow or outflow obstruction. While common in adults, cardiac myxomas presenting with generalized systemic illness or peripheral emboli especially with no cardiac or neurological symptoms are rare in children. CASE PRESENTATION: We report a case of a previously healthy adolescent girl who presented with a 6-month history of constitutional symptoms and a purpuric rash with no cardiac or neurologic symptoms, found to have a cardiac myxoma. CONCLUSIONS: A vasculopathic rash in the setting of atrial myxomas has been shown be a precursor to significant morbidity and mortality. Due to the rarity of this entity, the time elapsed from onset of non-cardiac symptoms until diagnosis of a myxoma is usually prolonged with interval development of irreversible neurological sequelae and death reported in the literature. Therefore, we highlight the importance of including cardiac myxomas and paraneoplastic vasculitis early in the differential diagnosis for patients presenting with a purpuric rash and systemic symptoms.

3D Printing is a Transformative Technology in Congenital Heart Disease.

Survival in congenital heart disease has steadily improved since 1938, when Dr. Robert Gross successfully ligated for the first time a patent ductus arteriosus in a 7-year-old child. To continue the gains made over the past 80 years, transformative changes with broad impact are needed in management of congenital heart disease. Three-dimensional printing is an emerging technology that is fundamentally affecting patient care, research, trainee education, and interactions among medical teams, patients, and caregivers. This paper first reviews key clinical cases where the technology has affected patient care. It then discusses 3-dimensional printing in trainee education. Thereafter, the role of this technology in communication with multidisciplinary teams, patients, and caregivers is described. Finally, the paper reviews translational technologies on the horizon that promise to take this nascent field even further.

3D Printing Provides a Precise Approach in the Treatment of Tetralogy of Fallot, Pulmonary Atresia with Major Aortopulmonary Collateral Arteries.

Patients with tetralogy of Fallot, pulmonary atresia, and multiple aortopulmonary collateral arteries (Tet PA MAPCAs) have a wide spectrum of anatomy and disease severity. Management of these patients can be challenging and often require multiple high-risk surgical and interventional catheterization procedures. These interventions are made challenging by complex anatomy that require the proceduralist to mentally reconstruct three-dimensional anatomic relationships from two-dimensional images. Three-dimensional (3D) printing is an emerging medical technology that provides added benefits in the management of patients with Tet PA MAPCAs. When used in combination with current diagnostic modalities and procedures, 3D printing provides a precise approach to the management of these challenging, high-risk patients. Specifically, 3D printing enables detailed surgical and interventional planning prior to the procedure, which may improve procedural outcomes, decrease complications, and reduce procedure-related radiation dose and contrast load.

Comparison of two-dimensional strain analysis using vendor-independent and vendor-specific software in adult and pediatric patients.

INTRODUCTION: Two-dimensional strain analysis is a powerful analysis modality, however, clinical utilization has been limited by variability between different analysis systems and operators. We compared strain in adults and children using vendor-specific and vendor-independent software to evaluate variability. METHODS: One hundred and ten subjects (50/110 pediatric, 80/110 normal left ventricular function) had echocardiograms with a General Electric ultrasound scanner between September 2010 and January 2012. Left ventricular longitudinal strain was derived with EchoPAC (General Electric, v10.8.1), a vendor-specific software, and Velocity Vector Imaging (Siemens, v3.5), which is vendor-independent. Three independent readers analyzed all the echocardiograms yielding 330 datasets. RESULTS: Mean left ventricular global longitudinal Lagrangian strain was -18.1 ± SD 4.4% for EchoPAC and -15.3 ± SD 4.1% for Velocity Vector Imaging. Velocity Vector Imaging yielded lower absolute global longitudinal Lagrangian strain by mean 2.9 (±SD 2.7, p < 0.0001), and lower regional longitudinal strain. These differences persisted in normal subjects versus those with cardiomyopathy. Longitudinal strain differences were slightly higher in the pediatric cohort. There was no significant difference in inter-observer longitudinal strain and a small difference in intra-observer strain between analysis systems. On repeat measurements, a significant change in global longitudinal Lagrangian strain occurred after the difference exceeded 3-5 strain points for EchoPAC and Velocity Vector Imaging, respectively. CONCLUSION: Velocity Vector Imaging produces lower left ventricular longitudinal strain values versus EchoPAC for the same echo images. Both systems have similar inter-observer variability, Velocity Vector Imaging slightly higher intra-observer variability. A statistically significant change in global longitudinal Lagrangian strain occurs with changes >3-5 strain points on repeat measurements. Strain values between the systems are not interchangeable.

The Impact of the Right Ventricular Outflow Tract Patch on Right Ventricular Strain in Tetralogy of Fallot: A Comparison with Valvar Pulmonary Stenosis Utilizing Cardiac Magnetic Resonance.

A non-contractile transannular patch (TAP) in the right ventricular outflow tract (RVOT) contributes to ventricular dysfunction after tetralogy of Fallot (TOF) repair. We compared regional right ventricular (RV) strain in repaired TOF with valvar pulmonary stenosis (VPS) after balloon valvuloplasty to investigate the effects of TAP. Retrospective review of 26 cardiac magnetic resonance studies of TOF (n = 13) and VPS (n = 13) subjects matched by degree and duration of pulmonary regurgitation (PR). Feature tracking strain analysis was performed. Student's t tests, Pearson correlation, and linear regression were applied. RV ejection fraction (EF) was normal and similar between TOF and VPS (60 and 65%, respectively, p = 0.8). RV 4-chamber Lagrangian longitudinal strain (RV 4ch LS) was worse in both groups compared to normals but comparable to each other: -18.2 (95% CI -3.6 to -33) for TOF and -20.2 (95% CI -12.4 to -28) for VPS, p = 0.5. RVOT LS was worse than RV 4ch LS in TOF, p = 0.05, but not in VPS, p = 0.19. There were no significant differences in RVOT strain between groups, p = 0.18. RVOT strain and RV 4ch LS correlated positively with RV EF in VPS (r = 0.72, p = 0.003 and r = 0.55, p = 0.04). PR degree correlated negatively with RVOT LS for TOF and VPS. Longitudinal strain is diminished in VPS and TOF subjects with preserved RV EF. TAP could explain worse RVOT strain in TOF. Longitudinal studies are needed to ascertain if RV strain predicts worsening of RV EF.

Rapid resolution of cardiac rhabdomyomas following everolimus therapy.

Cardiac rhabdomyoma is the most common primary cardiac tumour during childhood and is usually associated with tuberous sclerosis complex (TSC). These tumours are generally considered benign, and spontaneous regression occurs commonly. However, when the tumours cause significant symptoms, the current standard treatment is surgical resection. Everolimus is an mammalian target of rapamycin (mTOR) complex 1 inhibitor that has been successfully used to treat subependymal giant cell astrocytomas and renal angiomyolipomas associated with TSC. A few case reports have described the effectiveness of everolimus therapy in treating cardiac rhabdomyomas as well. We report a case of a newborn who had near complete resolution of multiple rhabdomyomas within a month of receiving everolimus therapy for non-cardiac masses. To the best of our knowledge, this is the fastest resolution of cardiac rhabdomyomas associated with everolimus therapy to date. Everolimus may be a promising alternative for high-risk surgical candidates with haemodynamically significant cardiac rhabdomyomas.

Leaving antegrade pulmonary blood flow results in reversal of flow in the azygous vein and decompression of the cavopulmonary circulation: mechanism of cyanosis defined with cardiac magnetic resonance imaging.

We report the case of a 2.5-year-old patient with single-ventricle physiology who underwent cardiac magnetic resonance study for cyanosis after Kawashima operation. Magnetic resonance imaging study showed a veno-venous collateral redirecting systemic venous flow, responsible for cyanosis.