Congenital Long QT Syndrome in Children and Adolescents: A General Overview.

Congenital long QT syndrome (LQTS) represents a disorder of myocardial repolarization characterized by a prolongation of QTc interval on ECG, which can degenerate into fast polymorphic ventricular arrhythmias. The typical symptoms of LQTS are syncope and palpitations, mainly triggered by adrenergic stimuli, but it can also manifest with cardiac arrest. At least 17 genotypes have been associated with LQTS, with a specific genotype-phenotype relationship described for the three most common subtypes (LQTS1, -2, and -3). ß-Blockers are the first-line therapy for LQTS, even if the choice of the appropriate patients needing to be treated may be challenging. In specific cases, interventional measures, such as an implantable cardioverter-defibrillator (ICD) or left cardiac sympathetic denervation (LCSD), are useful. The aim of this review is to highlight the current state-of-the-art knowledge on LQTS, providing an updated picture of possible diagnostic algorithms and therapeutic management.

Brugada Syndrome: Focus for the General Pediatrician.

Brugada Syndrome is an "inherited" channelopathy characterized by a predisposition to syncope and sudden death. It typically presents in young adults but is also known to affect the pediatric population, even if the prevalence is low compared to the adult population. The diagnostic ECG pattern shows coved-type ST-segment elevation in the right precordial leads, occurring spontaneously or after provocative drug tests with IV administration of Class I antiarrhythmic drugs. However, the electrocardiographic findings may vary, and transient or concealed forms of the syndrome further complicate diagnosis, necessitating thorough evaluation and close clinical follow-up. The clinical presentation of Brugada Syndrome may range from asymptomatic individuals to patients who have experienced syncope or sudden cardiac arrest. The syndrome remains underdiagnosed due to its elusive symptoms and the absence of abnormal findings between episodes. Additionally, specific triggers such as fever, certain medications and alcohol consumption may unmask the electrocardiographic changes and provoke arrhythmias in susceptible individuals. Given its elusive nature, early diagnosis and risk stratification are crucial in identifying individuals who may benefit from an implantable cardioverter defibrillator, the mainstay of treatment for high-risk patients, or pharmacological interventions.

Renal and Multiorgan Safety of 177Lu-PSMA-617 in Patients with Metastatic Castration-Resistant Prostate Cancer in the VISION Dosimetry Substudy.

In the VISION trial, [177Lu]Lu-PSMA-617 (177Lu-PSMA-617) plus protocol-permitted standard of care significantly improved overall survival and radiographic progression-free survival compared with standard of care alone in patients with prostate-specific membrane antigen-positive metastatic castration-resistant prostate cancer. This VISION dosimetry substudy quantified absorbed doses of 177Lu-PSMA-617 in the kidneys and other organs. Methods: Participants were a separate cohort of 30 nonrandomized patients receiving standard of care plus 177Lu-PSMA-617 at 7.4 GBq per cycle for up to 6 cycles. Blood samples, whole-body conjugate planar image scintigraphy, and abdominal SPECT/CT images were collected. SPECT/CT images were collected at 2, 24, 48, and 168 h after administration in cycle 1 and at a single time point 48 h after administration in cycles 2-6. Outcomes were absorbed dose per unit activity per cycle and cumulative absorbed dose over all cycles. Cumulative absorbed doses were predicted by extrapolation from cycle 1, and calculation of observed values was based on measurements of cycle 1 and cycles 2-6. Safety was also assessed. Results: Mean (±SD) absorbed doses per cycle in the kidneys were 0.43 ± 0.16 Gy/GBq in cycle 1 and 0.44 ± 0.21 Gy/GBq in cycles 2-6. The observed and predicted 6-cycle cumulative absorbed doses in the kidneys were 15 ± 6 and 19 ± 7 Gy, respectively. Observed and predicted cumulative absorbed doses were similar in other at-risk organs. Safety findings were consistent with those in the VISION study; no patients experienced renal treatment-emergent adverse events of a grade higher than 3. Conclusion: The renal cumulative absorbed 177Lu-PSMA-617 dose was below the established limit. 177Lu-PSMA-617 had a good overall safety profile, and low renal radiotoxicity was not a safety concern. Cumulative absorbed doses in at-risk organs over multiple cycles can be predicted by extrapolation from cycle 1 data in patients with metastatic castration-resistant prostate cancer receiving 177Lu-PSMA-617.

Characterization of Cardiac Function by Echocardiographic Global Longitudinal Strain in a Cohort of Children with Neurofibromatosis Type 1 Treated with Selumetinib.

BACKGROUND: Plexiform neurofibromas are benign neoplasms that develop in 20-50% children with neurofibromatosis type 1 (NF1). Selumetinib was approved as treatment for symptomatic and inoperable plexiform neurofibromas. Subclinical left ventricular ejection fraction reduction is a less common effect of selumetinib. OBJECTIVE: We aimed to investigate the contractile function of the heart in a cohort of children with NF1 treated with selumetinib. METHODS: We designed a cross-sectional study including 17 patients with NF1 who received selumetinib. Echocardiographic parameters were compared with a cohort of 17 healthy children matched by sex and age and another group of 17 children with untreated NF1. RESULTS: Compared with healthy controls, patients with NF1 treated with selumetinib had lower mean values of global longitudinal strain (- 22.9 ± 2% vs -25.5 ± 2%; p = 0.001), fractional shortening (36 ± 4% vs 43 ± 8%; p = 0.02) and tricuspid annular plane systolic excursion (19 ± 3 mm vs 23 ± 2 mm; p = 0.001); no difference was found in left ventricular ejection fraction (63 ± 4% vs 65 ± 3%; p = 0.2 respectively). Median treatment time with selumetinib at the time of the echocardiographic evaluation was 22 ± 16 months. CONCLUSIONS: Patients with NF1 treated with selumetinib may experience subtle changes in systolic function identified by global longitudinal strain and not revealed by left ventricular ejection fraction. Global longitudinal strain might be useful to monitor cardiac function in this cohort of patients for the duration of therapy.

Cardiac MRI in midterm follow-up of MISC: a multicenter study.

In this multicenter retrospective study we aimed to evaluate the outcome of cardiac involvement in children affected by multisystem inflammatory syndrome (MIS-C), assessed through cardiac magnetic resonance (CMR). Children referring to three Italian tertiary pediatric centers between February 2020 and November 2021 with a diagnosis of MIS-C, who underwent CMR during a follow-up visit, were enrolled. Demographic, clinical, laboratory, treatment, and outcome data were collected. Twenty MIS-C patients (aged 9-17, median 12 years) were included in the study. Heart involvement at onset was testified by hypotension/shock (55%), laboratory evidence of myocardial involvement (100%), reduced LV ejection fraction (EF) on echocardiography (83%), and/or need for inotrope agents (40%); they all presented good clinical, laboratory, and echocardiographic response to treatment. CMR was performed after a median interval of 3 months from discharge. Pericardial effusion and myocardial edema were found in 5% of patients. Mild residual left ventricular (LV) dysfunction was found in 20% of patients, all showing normal echocardiographic LVEF at discharge. Minimal myocardial scars were found in 25% by late gadolinium enhancement (LGE). One patient was evaluated at two consecutive time points, showing partial resolution of a myocardial scar after 7 months from its first finding. CONCLUSION: Despite the severity of heart involvement in the acute MIS-C phase, the mid-term cardiac outcome is good. Direct cardiac tissue viral invasion may be involved in MIS-C pathogenesis. WHAT IS KNOWN: • Heart involvement is common in MIS-C, but conflicting findings have been shown regarding cardiac outcome when assessed through cardiac MRI. WHAT IS NEW: • Midterm cardiac MRI shows mild abnormalities in patients recovered from MIS-C with any grade of severity of cardiac involvement at presentation.

Long QT syndrome and left ventricular non-compaction in a family with KCNH2 mutation: A case report.

Background: Left ventricular non-compaction (LVNC) is an abnormality of the myocardium, characterized by prominent left ventricular trabeculae and deep inter-trabecular recesses. Long QT syndrome (LQTS) is a cardiac ion channelopathy presenting with a prolonged QT interval on resting electrocardiogram and is associated with increased susceptibility to sudden death. The association between LVNC and LQTS is uncommon. Case presentation: We report an Italian family with a novel pathogenic KCNH2 variant who presented with clinical features of LVNC and LQTS. The proband came to our attention after two syncopal episodes without prodromal symptoms. His ECG showed QTc prolongation and deep T wave inversion in anterior leads, and the echocardiogram fulfilled LVNC criteria. After that, also his sister was found to have LQTS and LVNC, while his father only presented LQTS. Conclusions: Physicians should be aware of the possible association between LVNC and LQTS. Even if this association is rare, patients with LVNC should be investigated for LQTS to prevent possible severe or even life-threatening arrhythmic episodes.

Cardio-pulmonary function among children with mild or asymptomatic COVID-19 infection needing certification for return-to-play.

AIM: To explore the cardio-pulmonary function of children returning to play sports after mild or asymptomatic SARS-CoV-2 infection. METHODS: This is a consecutive case series conducted at the Institute for Maternal and Child Health, Trieste, Italy. Paediatric patients who accessed the Institute for cardiologic and pneumological evaluation before the return-to-play competitive sports were recruited, according to the Italian Sports Medical Federation recommendations. Echocardiogram, electrocardiogram, treadmill ECG test and pulmonary function tests were performed. RESULTS: One hundred and thirty-two patients (aged 8-17 years old, mean age 12.8 ± 2.5) were recruited. Among these, 127 children were considered for the final analysis (49.6% females). Out of 127, 84 (66.1%) had a mild symptomatic form of SARS-CoV-2 infection, while 43 (33.9%) were asymptomatic. The main referred symptoms were fever (n = 37, 44%), asthenia (n = 14, 16.7%), rhinitis (n = 16, 19%), ageusia (n = 19, 22.6%), anosmia (n = 24, 28.6%), sore throat (n = 3, 3.6%), cough (n = 9, 10.7%), arthralgia-myalgia (n = 11, 13.1%), headache (n = 23, 27.4%) and gastrointestinal symptoms (n = 7, 8.3%). No child presented evidence of cardio-pulmonary function impairment after an average time of 77.3 days (SD 35) from SARS-CoV-2 swab positivity and a median of 68 days (IQ1 52, IQ3 92.5). CONCLUSION: This preliminary study suggests that, in the absence of specific symptoms, the diagnostic yield of cardio-pulmonary tests before returning to play sports may be very low.

Anomalous aortic origin of coronary artery: For a challenging diagnosis, a transthoracic echocardiogram is recommended.

Anomalous aortic origin of a coronary artery (AAOCA), especially the interarterial course of the right or left coronary artery, predisposes paediatric patients to myocardial ischaemia. This rare condition is a leading cause of sudden cardiac death. General paediatricians face challenges when diagnosing this anomaly, and they should pay particular attention to the recurrence of exercise-related syncope without prodromal symptoms, chest pain and dyspnoea. An accurate transthoracic echocardiogram with Doppler colour flow mapping is the best method to use to identify AAOCA. CONCLUSION: Identifying an AAOCA is challenging, and we provide advice on clinical red flags and diagnostic approaches for general paediatricians.

Inter and intra-tumor somatostatin receptor 2 heterogeneity influences peptide receptor radionuclide therapy response.

Patients with neuroendocrine tumors (NETs) can be treated with peptide receptor radionuclide therapy (PRRT). Here, the somatostatin analogue octreotate radiolabeled with lutetium-177 is targeted to NET cells by binding to the somatostatin receptor subtype 2 (SST2). During radioactive decay, DNA damage is induced, leading to NET cell death. Although the therapy proves to be effective, mortality rates remain high. To appropriately select more optimal treatment strategies, it is essential to first better understand the radiobiological responses of tumor cells to PRRT. Methods: We analyzed PRRT induced radiobiological responses in SST2 expressing cells and xenografted mice using SPECT/MRI scanning and histological and molecular analyses. We measured [177Lu]Lu-DOTA-TATE uptake and performed analyses to visualize induction of DNA damage, cell death and other cellular characteristics. Results: The highest accumulation of radioactivity was measured in the tumor and kidneys. PRRT induced DNA damage signaling and repair in a time-dependent manner. We observed intra-tumor heterogeneity of DNA damage and apoptosis, which was not attributed to proliferation or bioavailability. We found a strong correlation between high DNA damage levels and high SST2 expression. PRRT elicited a different therapeutic response between models with different SST2 expression levels. Heterogeneous SST2 expression levels were also confirmed in patient NETs. Conclusion: Heterogeneous SST2 expression levels within NETs cause differentially induced DNA damage levels, influence recurrent tumor phenotypes and impact the therapeutic response in different models and potentially in patients. Our results contribute to a better understanding of PRRT effects, which might impact future therapeutic outcome of NET patients.

Speeding up coeliac disease diagnosis in cardiological settings.

INTRODUCTION: High prevalence of coeliac disease (CD) has been reported among patients with idiopathic dilated cardiomyopathy (DCM). We evaluated the feasibility and diagnostic accuracy of screening for CD by rapid test of anti-transglutaminase antibodies in the cardiology outpatients' clinic. MATERIAL AND METHODS: We screened the blood samples of 104 patients with DCM, 44 of their first-degree relatives, 63 diseased controls and 101 healthy controls for the presence of anti-transglutaminase antibodies in a drop of whole blood using a rapid assay. This test was compared to the enzyme-linked immunosorbent assay and the anti-endomysium antibody test. RESULTS: Our rapid test was positive in three (2.9%) DCM patients, in one (2%) relative and in one (1%) healthy control. These subjects were positive at both control assays. Two DCM patients had iron-deficient anaemia. The healthy relative was asymptomatic, while the healthy control experienced extreme asthenia. The relative refused intestinal biopsy, while the others showed histological evidence of CD. During the gluten-free diet, the patient with the worst left ventricular ejection fraction (LVEF) underwent heart transplant, and LVEF values improved in the other two. Anaemia and tiredness resolved in all patients. CONCLUSION: Early detection of CD in a cardiological setting allows prompt treatment with a gluten-free diet of gluten-dependent complaints with potential benefits for the course of DCM.

NMR conformational analysis of antide, a potent antagonist of the gonadotropin releasing hormone.

Antide is a decapeptide [(N-Ac-D-Nal(1)-D-Cpa(2)-D-Pal(3)-Ser(4)-Lys(Nic)(5)-D-Lys(Nic)(6)-Leu(7)-Ilys(8)-Pro(9)-D-Ala(10)-NH(2)] that acts in vivo as an antagonist of GnRH (gonadotropin-releasing hormone). The conformational behavior of antide has been studied in water, TFE, DMF, and DMSO solutions by means of 2D-NMR spectroscopy and molecular dynamics calculations. Antide adopts in aqueous solution a delta-shaped backbone conformation, which is characterized by an irregular turn around residues D-Pal(3)-Ser(4) and by the close spatial proximity of the side chains belonging to D-Nal(1) and Ilys(8) (as many as 17 NOE peaks were detected between these side chains). The side-chain protons of Ilys(8) (especially the H(gamma) ones) present remarkably upfield shifted resonances, because of ring current effects induced by the naphthyl moiety. The upfield shifted resonances of the Ilys(8) H(gamma) hydrogen atoms are strictly characteristic of the water delta-shaped conformation and can be considered as structure markers. The observation of ring current shifted Ilys(8) H(gamma) resonances under different conditions (temperature, pH, solvent) indicates a remarkable stability of the water delta-shaped conformation. Such a conformation is at least partially disrupted in solvent mixtures containing high percentages of organic solvents. TFE can induce a well-defined conformation, which is characterized by an S-shaped backbone conformation. In DMF and DMSO solution, the molecule is basically endowed with a random coil conformation and high fluxionality. Antide fulfills the conformational requirements that are known to play a crucial role in receptor recognition, namely (i) the presence of a turn in the backbone and (ii) the all-trans nature of peptide bonds. In addition, the structural rigidity of antide likely adds a further contribution to the receptor binding affinity.