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Clinical and prognostic role of cardiac magnetic resonance (CMR) in adult population with hypertrophic cardiomyopathy (HCM) have been largely assessed. We sought to investigate the role of CMR for predicting cardiovascular events in children with HCM.CMR was performed in 116 patients with HCM (37 sarcomeric mutations, 31 other mutations, mean age 10.4 ± 4.3 yrs). CMR protocol included cine imaging for evaluation of morphology and function and late gadolinium enhancement (LGE). Hard cardiac events (sustained VT, resuscitated cardiac arrest, sudden cardiac death, end-stage heart failure, heart transplant and appropriate ICD intervention) were recorded through a median follow-up of 4 (1-7) years.During follow-up 21 heart cardiac events occurred. At maximal-rank statistic the optimal cut-point for LGE extent for predicting events was ≥2%. Syncope, non-sustained ventricular tachycardia (NSVT) and LGE extent ≥2% were independent predictors of events. At Harrel's C statistic combination of LGE extent ≥2% and syncope was the strongest model for predicting events. HR of patients with LGE extent ≥2% and no history of syncope was 3.6 (1.1-12.2) that increased to 37.6 (5.4-161) in those with LGE extent ≥2% and syncope. The median time dependent AUC of LGE extent (0.88, 95% CI 0.86-0.89) was significantly higher than that of syncope (0.63, 95% CI 0.61-0.66, p 0.0001) and NSVT (0.52, 95% CI 0.50-0.53, p 0.0001).In children with HCM, LGE and syncope were independent predictors of hard cardiac events at follow-up.

BackgroundIn patients with repaired Fallot, subsequent surgical or interventional procedures and adverse cardiac events are frequent. We aimed to evaluate the impact of a simple pre-operative anatomic classification based on the size of the pulmonary valve (PV) annulus and branches on future therapeutic requirements and outcomes.MethodThis is a single-center retrospective analysis of patients operated for Fallot before the age of 2 years, from January 1990. Pre-operative anatomy, surgical and interventional procedures and adverse events were extrapolated from clinical records.ResultsAmong the 312 patients, a description of the PV and pulmonary arteries (PAs) native anatomy was known in 239 patients (male:147, 61.5%), which were divided in the following 3 groups: group 1 (65 patients) with normal size of both PV and PAs; group 2 (108 patients) with PV hypoplasia but normal size PAs; group 3 (66 patients) with concomitant hypoplasia of the PV and PAs. During the 12.7 years (IQR 6.7–17) follow-up time, 23% of patients required at least one surgical or interventional procedure. At Kaplan–Meier analysis, there was a significant difference in requirement of future surgical or interventional procedures among the 3 groups (p p = 0.03).ConclusionNative anatomy in Tetralogy of Fallot patients affects surgical strategy and follow-up. It would be therefore advisable to tailor patient’s counseling and follow-up according to native anatomy, rather than following a standardized protocol.

Congenital heart disease (CHD) and cardiomyopathies represent the two most important causes of paediatric heart failure (HF) in developed countries. We made a review of the literature on pathophysiology and clinical presentation of paediatric HF in children with CHD. Two main pathophysiologic models can be identified: the 'over-circulation failure', characterised by signs and symptoms of congestion or hypoperfusion, due respectively to volume or pressure overload, and the 'pump failure'. CONCLUSIONS: The comprehension of the HF pathophysiology in paediatric patients with CHD is of paramount importance for the optimal management and for addressing the best therapeutic choices.

Genetic investigation of early‐onset Dilatative cardiomyopathy phenotype, including molecular autopsy, is the key to appropriate recognition and management of rare etiologies and atypical presentations and to offer genetic counseling to the family.

Childhood hypertrophic cardiomyopathy; Outcomes; Phenotype Miocardiopatía hipertrófica infantil; Resultados; Fenotipo Miocardiopatia hipertròfica infantil; Resultats; Fenotip Background Up to one-half of childhood sarcomeric hypertrophic cardiomyopathy (HCM) presents before the age of 12 years, but this patient group has not been systematically characterized. Objectives The aim of this study was to describe the clinical presentation and natural history of patients presenting with nonsyndromic HCM before the age of 12 years. Methods Data from the International Paediatric Hypertrophic Cardiomyopathy Consortium on 639 children diagnosed with HCM younger than 12 years were collected and compared with those from 568 children diagnosed between 12 and 16 years. Results At baseline, 339 patients (53.6%) had family histories of HCM, 132 (20.9%) had heart failure symptoms, and 250 (39.2%) were prescribed cardiac medications. The median maximal left ventricular wall thickness z-score was 8.7 (IQR: 5.3-14.4), and 145 patients (27.2%) had left ventricular outflow tract obstruction. Over a median follow-up period of 5.6 years (IQR: 2.3-10.0 years), 42 patients (6.6%) died, 21 (3.3%) underwent cardiac transplantation, and 69 (10.8%) had life-threatening arrhythmic events. Compared with those presenting after 12 years, a higher proportion of younger patients underwent myectomy (10.5% vs 7.2%; P = 0.045), but fewer received primary prevention implantable cardioverter-defibrillators (18.9% vs 30.1%; P = 0.041). The incidence of mortality or life-threatening arrhythmic events did not differ, but events occurred at a younger age. Conclusions Early-onset childhood HCM is associated with a comparable symptom burden and cardiac phenotype as in patients presenting later in childhood. Long-term outcomes including mortality did not differ by age of presentation, but patients presenting at younger than 12 years experienced adverse events at younger ages. This work was supported by the British Heart Foundation (grant FS/16/72/32270) to Drs Norrish and Kaski. This work is (partly) funded by the National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre. Dr Norrish is supported by Great Ormond Street Hospital Children’s Charity. Drs Field and Kaski are supported by Max’s Foundation and Great Ormond Street Hospital Children’s Charity. Dr Kaski is supported by a Medical Research Council–National Institute for Health Research Clinical Academic Research Partnership award. This work was financially supported by the Foundation for Paediatric Research of Finland (Dr Ojala). Dr Fernandez has received speaker fees from Sanofi-Genzyme. Dr Kubus is supported by MH CZ – DRO, Motol University Hospital (00064203). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Aims Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM). The newly developed HCM Risk-Kids model provides clinicians with individualized estimates of risk. The aim of this study was to externally validate the model in a large independent, multi-centre patient cohort. Methods and results A retrospective, longitudinal cohort of 421 patients diagnosed with HCM aged 1–16 years independent of the HCM Risk-Kids development and internal validation cohort was studied. Data on HCM Risk-Kids predictor variables (unexplained syncope, non-sustained ventricular tachycardia, maximal left ventricular wall thickness, left atrial diameter, and left ventricular outflow tract gradient) were collected from the time of baseline clinical evaluation. The performance of the HCM Risk-Kids model in predicting risk at 5 years was assessed. Twenty-three patients (5.4%) met the SCD end-point within 5 years, with an overall incidence rate of 2.03 per 100 patient-years [95% confidence interval (CI) 1.48–2.78]. Model validation showed a Harrell’s C-index of 0.745 (95% CI 0.52–0.97) and Uno’s C-index 0.714 (95% 0.58–0.85) with a calibration slope of 1.15 (95% 0.51–1.80). A 5-year predicted risk threshold of ≥6% identified 17 (73.9%) SCD events with a corresponding C-statistic of 0.702 (95% CI 0.60–0.81). Conclusions This study reports the first external validation of the HCM Risk-Kids model in a large and geographically diverse patient population. A 5-year predicted risk of ≥6% identified over 70% of events, confirming that HCM Risk-Kids provides a method for individualized risk predictions and shared decision-making in children with HCM.

Background: Maximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort. Methods: The study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1–16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids). Results: MLVWT Z score was Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3–9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk. Conclusions: In children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.

OBJECTIVE To evaluate the GORE® Cardioform ASD Occluder (GCO) (WL Gore & Associates, Flagstaff, AZ) device for "complex" atrial septal defects (ASD) closure. BACKGROUND Transcatheter ASD closure is still challenging in "complex" clinical/anatomic settings. This study evaluated the results of GCO in closure of "complex" ASD in a tertiary referral center. METHODS Between January 2020 and March 2021, 72 patients with significant ASD were submitted to transcatheter closure with GCO at our Institution. Based on clinical/anatomic characteristics, they were classified as "complex" (n = 36, Group I) or "simple" (n = 36, Group II). We considered as "complex", defects with rim deficiency ( 1.2 or diameter/patient BSA > 20 mm/m2 ) or within a multifenestrated septum. Procedure results and early outcome were compared between the groups. RESULTS Absolute and relative ASD size (20 ± 4 vs. 15 ± 3 mm, p

Introduction Sudden cardiac death is the most common cause of mortality in childhood onset hypertrophic cardiomyopathy. Identifying individuals at highest risk is therefore an essential part of clinical care but remains challenging. The 12 lead electrocardiogram (ECG) has been proposed as a useful tool for risk stratification and an ECG risk score has been proposed. However, this has not been independently validated and the ECG phenotype of childhood HCM has not been previously described. The aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events. Methods Participants with an available baseline resting 12-lead ECG were identified from a large, international, multi-centre, retrospective cohort of patients aged less than 16 years fulfilling the diagnostic criteria for HCM (n=1029). Resting baseline ECG was evaluated and ECG variables were extracted. In addition, the ECG risk score based on 8 parameters (deviation in QRS axis, pathological T-wave inversion in limb or precordial leads, ST-segment depression, dominant S-wave in V4, limb-lead amplitude sum, 12-lead amplitude duration product and QTc) was calculated as previously described. The primary study endpoint was a composite outcome of major cardiac events (MACE) defined as SCD, resuscitated cardiac arrest, appropriate implantable cardioverter defibrillator therapy, or sustained ventricular tachycardia (VT) with haemodynamic compromise. The discriminatory performance of using an ECG risk score >5 to identify patients at increased risk of MACE at 5 years was determined using Harrell’s C-index. Results Of 356 patients with childhood HCM (68.9% male, mean age at presentation 10.1 ± 4.5 years), 347 (97.5%) had baseline ECG abnormalities such as: repolarization abnormalities (n=277, 77.8%), left ventricular hypertrophy (n=240. 67.6%), abnormal QRS axis (n=126, 35.4%) or QT prolongation (n=131, 36.8%). Over a median follow up of 3.9 years (IQR 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year MACE on univariable or multivariable Cox regression analysis. Of the 164 participants with an ECG score >5, 153 (93.3%) did not have a MACE within 5 years. Harrell’s C-index (the probability of correctly distinguishing between high and low risk patients using an ECG risk score threshold of >5) was 0.60 (95% CI 0.484-0.715) at 5 years. The corresponding positive and negative predictive values were 6.7% (95% CI 4.7 – 9.4%) and 96.9% (95% CI 94.2 – 98.4%). Conclusions In a large, international, multi-centre cohort of children with HCM, ECG abnormalities are common. No ECG characteristic, either in isolation or combined in the ECG risk score, was associated with 5-year MACE risk. This suggests that the role of the baseline ECG phenotype in improving risk stratification in childhood HCM is limited. Conflict of Interest None

Aims The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events. Methods and results Data from 356 childhood HCM patients with a mean age of 10.1 years (±4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0–7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93–2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484–0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7% Conclusion In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited.

Introduction:The single- and double-patch repairs are undoubtedly the most commonly used techniques for the surgical management of partial anomalous pulmonary venous connection associated with sinus venosus atrial septal defect. The aim of this study was to retrospectively compare early and long-term surgical outcomes in paediatric and adult patients, focusing in particular on the occurrence of ectopic atrial rhythm.Material and methods:Seventy patients (male: 38, 54.2%) underwent surgical repair for partial anomalous pulmonary venous connection with sinus venosus atrial septal defect. Forty-nine patients (70%) underwent surgical repair in paediatric age (Results:The type of surgical technique didn’t affect the incidence of ectopic atrial rhythm (26.6% in single-patch group and 25.6% in double-patch groups, p = 0.9). At long-term follow-up, ectopic atrial rhythm, as an expression of sinoatrial node disturbance, was however significantly more frequent in the paediatric population (28.8% paediatric group and 4.7% adult group, p = 0.02).Conclusions:The higher incidence of ectopic atrial rhythm in children is probably related to the closer position of the sinus node to the superior cavoatrial incision, which makes irreversible iatrogenic traumatism more likely to occur. Surgical techniques that avoid any manipulation on the superior cavoatrial junction should, therefore, be preferred for children undergoing partial anomalous pulmonary venous connection repair.

Background and aim of the study The single- and double-patch repairs are the most commonly used techniques for the surgical management of partial anomalous pulmonary venous connection associated with sinus venosus atrial septal defect. The aim of this study was to retrospectively compare early and long-term surgical outcomes in pediatric and adult patients, focusing in particular on the occurrence of postoperative rhythm disturbances. Methods 115 patients (male: 63, 54.8%) underwent surgical repair for partial anomalous pulmonary venous connection with sinus venosus atrial septal defect. 80 patients (70.4%) underwent surgical repair in pediatric age (

The hemodynamic impact of residual pulmonary regurgitation (PR) in repaired Tetralogy of Fallot (rTOF) has been well demonstrated. However, markers driving the decision making process to indicate the ideal timing of pulmonary valve replacement (PVR) are still uncertain. Furthermore, very few studies have included the right atrium (RA) dilatation as a preoperative risk factor for post-PVR clinical adverse outcome. The aim of this study was to investigate the impact of pre-PVR right atrial dilation on adverse outcomes in rTOF. We retrospectively reviewed from our CMR database all rTOF patients who underwent CMR study before and after PVR. Detailed clinical and surgical history were collected, in addition to imaging data. The composite primary and secondary post-PVR end points were also recorded. The study cohort consisted of 41 patients (mean age at PVR repair 27.4 ± 10 years). As expected, end-diastolic and end-systolic right ventricle (RV) volumes significantly decreased after PVR (p

Norwood procedure is the most common surgical treatment strategy for hypoplastic left heart syndrome (HLHS) (1). Although advances in surgical techniques and postoperative care have significantly improved the survival rates after Norwood, a significant proportion of children develop heart failure (HF) at different stages of palliation (1,2).

OBJECTIVES Heart transplantation (HTx) in children with a univentricular physiology is a challenge. In this study, we aimed to investigate the early and late survival as well as the causes of death of HTx recipients at different stages of univentricular palliation. METHODS Between January 1987 and September 2015, 40 orthotropic cardiac transplants were performed in 38 children with univentricular hearts at our institution. Outcomes were reviewed using medical records and transplant databases. RESULTS For the purposes of this analysis, patients were divided into 3 subgroups according to their stage of palliation: Stage 1 (n = 10, 26%), Stage 2 (n = 5, 13%) and Fontan (n = 23, 61%). The median age at HTx was 15.2 years (range 0-38). The median follow-up time after transplantation was 8.7 years (range 0-25.4). Indications for transplant were ventricular dysfunction in 25 (66%) patients, protein losing enteropathy in 10 patients transplanted in Fontan (26%) and refractory arrhythmias in 3 (8%) patients with an atriopulmonary connection. Total mortality was 42% (4.84/100 patient-years), and total early mortality was 21%. Overall survival at 1, 10 and 20 years was 73% (95% confidence interval 56-84%), 58% (95% confidence interval 40-72%) and 49% (95% confidence interval 30-65%), respectively. CONCLUSIONS HTx is a feasible option for patients with failing univentricular circulation, and although the mortality rate is high, this rate is still comparable to that in patients undergoing HTx for other congenital and non-congenital heart diseases.

We here report a neonate with prenatal echocardiographic diagnosis of tricuspid atresia, with normally related great vessels, and large ventricular septal defect. This diagnosis could be confirmed with echocardiography at birth. An additional double mitral orifice was also seen. This is a very rare association.

Importance: Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM), but there is no validated algorithm to identify those at highest risk.Objective: To develop and validate an SCD risk prediction model that provides individualized risk estimates.Design, Setting, and Participants: A prognostic model was developed from a retrospective, multicenter, longitudinal cohort study of 1024 consecutively evaluated patients aged 16 years or younger with HCM. The study was conducted from January 1, 1970, to December 31, 2017.Exposures: The model was developed using preselected predictor variables (unexplained syncope, maximal left-ventricular wall thickness, left atrial diameter, left-ventricular outflow tract gradient, and nonsustained ventricular tachycardia) identified from the literature and internally validated using bootstrapping.Main Outcomes and Measures: A composite outcome of SCD or an equivalent event (aborted cardiac arrest, appropriate implantable cardioverter defibrillator therapy, or sustained ventricular tachycardia associated with hemodynamic compromise).Results: Of the 1024 patients included in the study, 699 were boys (68.3%); mean (interquartile range [IQR]) age was 11 (7-14) years. Over a median follow-up of 5.3 years (IQR, 2.6-8.3; total patient years, 5984), 89 patients (8.7%) died suddenly or had an equivalent event (annual event rate, 1.49; 95% CI, 1.15-1.92). The pediatric model was developed using preselected variables to predict the risk of SCD. The model's ability to predict risk at 5 years was validated; the C statistic was 0.69 (95% CI, 0.66-0.72), and the calibration slope was 0.98 (95%, CI 0.59-1.38). For every 10 implantable cardioverter defibrillators implanted in patients with 6% or more of a 5-year SCD risk, 1 patient may potentially be saved from SCD at 5 years.Conclusions and Relevance: This new, validated risk stratification model for SCD in childhood HCM may provide individualized estimates of risk at 5 years using readily obtained clinical risk factors. External validation studies are required to demonstrate the accuracy of this model's predictions in diverse patient populations.

Williams syndrome (WS) is a genetic disorder due to deficiency of elastin gene expression. It is characterized by typical somatic abnormalities and a wide range of cardiovascular malformations. Coronary artery involvement is a frequent finding of the syndrome, particularly in those patients with severe supravalvular aortic stenosis. We present the case of an 11-month-old infant affected by WS who developed severe coronary artery disease 2 months after the surgical repair of supravalvular aortic stenosis. The clinical picture and successful surgical revascularization strategy is also described.

The benefits of prophylactic anticoagulation or antiplatelet therapy for patients undergoing extracardiac conduit (ECC) Fontan procedure still are a matter of debate. Through a systematic review and meta-analysis, this study aimed to determine the incidence of thromboembolism among patients undergoing ECC Fontan who received anticoagulation or antiplatelet therapy. Until February 2010, MEDLINE studies describing the incidence of thromboembolic events after ECC Fontan were reviewed. Information on type of drugs and clinical outcome was extracted. The 20 studies analyzed involved 1,075 patients: 220 (20.4%) in the antiplatelet group and 855 (79.5%) in the anticoagulation group. The mean follow-up period ranged from 2 to 144 months. The overall thromboembolism rate was 5.2% (95% confidence interval [CI], 3.8-7%; I(2) = 0%; p(het) = 0.32). The effect of different therapeutic strategies on the occurrence of thromboembolic and bleeding events was analyzed. Interestingly, the anticoagulation therapy compared with the antiplatelet therapy was not associated with a significant reduction in the incidence of overall thromboembolic complications (5% vs 4.5%, respectively; I(2) = 0%; p(het) = 0.80). Only two cases of bleeding were observed among patients receiving anticoagulant therapy at the time of the event. For patients undergoing ECC Fontan, the rate of thromboembolic and bleeding events associated with antiplatelet therapy is similar to that associated with anticoagulation therapy.

A critical infant with unrestrictive ventricular septal defect and absence of the left pulmonary artery underwent transcatheter re-canalization of the occluded arterial duct-left pulmonary artery complex and surgical banding of the right pulmonary artery. After this hybrid approach, the baby was discharged under mild anticongestive therapy in view of a later surgical repair.

The aim of this study was to compare the pulmonary artery (PA) growth after arterial duct (AD) stenting versus modified Blalock-Taussig shunt (MBTS) in neonates with congenital heart disease with duct-dependent pulmonary circulation (CHD-DPC).Arterial duct stenting is increasingly deemed a reliable alternative to surgical shunt in CHD-DPC. A stented duct might better adapt to the PA anatomy than a surgical conduit, thereby promoting a more uniform PA development.This study enrolled 27 patients with CHD-DPC submitted to AD stenting (n = 13, Group I) or MBTS (n = 14, Group II) at our institution. The PA growth was angiographically assessed with the Nakata and McGoon indexes as well as the individual PA z-scores. The right-to-left PA diameter ratio was considered as index of uniform growth.After 10 +/- 5 months, both options had promoted a significant increase of the Nakata index (from 136 +/- 72 mm/m(2) to 294 +/- 99 mm/m(2), p0.0001, Group I; from 151 +/- 74 mm/m(2) to 295 +/- 177 mm/m(2), p0.003, Group II) and McGoon ratio (from 1.5 +/- 0.3 to 2.1 +/- 0.3, p0.0001, Group I; from 1.6 +/- 0.3 to 2.0 +/- 0.5, p0.01, Group II). However, the surgical shunt had caused a worsening of the left-to-right PA diameter ratio compared with AD stenting (0.9 +/- 0.1 Group I vs. 1.6 +/- 0.9 Group II, p0.01), due to preferential growth of the PA contralateral to the shunt.Percutaneous AD stenting is as effective as MBTS in promoting a global PA growth in CHD-DPC. In addition, it ensures an even distribution of the pulmonary blood flow, thereby promoting a more balanced pulmonary vascular development than MBTS.

A 2 month-old infant with severe congestive heart failure due to unrestrictive ventricular septal defect and absence of the left pulmonary artery was submitted to a hybrid transcatheter-surgical palliation consisting in percutaneous re-canalization of the occluded arterial duct-left pulmonary artery complex and surgical banding of the right pulmonary artery. The post-operative course was uneventful and the baby was discharged in a few days under mild anti-congestive therapy. This hybrid approach was highly effective in stabilizing this critical infant in view of a later and safer surgical repair.

Cardiac hypertrophy by activation of the beta-adrenergic receptor (beta AR) is mediated more efficiently by the beta1-AR than by the beta2-AR. We investigated the signalling mechanism by which the beta1-AR mediates cardiac hypertrophy.Experiments were performed in cultured neonatal rat cardiomyocytes. Hypertrophy was determined by the protein/DNA content and atrial natriuretic factor transcription. Phosphorylation of Akt and Src was assessed by immunoblotting. Isoproterenol (ISO, 10 microM), a non-selective beta-AR agonist, caused selective downregulation of the beta1-AR (control beta1 vs. beta2: 35 vs. 65%, Bmax 78 +/- 4 fmol/mg; 4 h, 10 vs. 90%, 61 +/- 5 fmol/mg). Concanavalin A (Con A, 0.5 microg/mL), an inhibitor of endocytosis, prevented downregulation of beta1-ARs by ISO treatment (4 h, 35 vs. 65%, 73 +/- 8 fmol/mg), suggesting that beta1-ARs selectively undergo endocytosis. Interference with beta1-AR endocytosis by Con A, carboxyl terminal peptide of beta-AR kinase-1, dominant negative (DN) beta-arrestin-1, or DN dynamin inhibited beta-adrenergic hypertrophy, suggesting that the endocytosis machinery plays a key role in mediating beta-adrenergic hypertrophy. Activation of Akt by the beta1-AR was blocked by inhibition of the endocytosis machinery, suggesting that endocytosis mediates activation of Akt. Akt plays a critical role in beta-adrenergic hypertrophy, since DN Akt blocked ISO-induced hypertrophy. beta-Adrenergic activation of Akt is mediated by Src, which associates with the endocytosis machinery and is necessary and sufficient to mediate beta-adrenergic hypertrophy.Activation of the endocytosis machinery is required for activation of Akt, which, in turn, critically mediates beta1-AR-induced cardiac hypertrophy.

OBJECTIVE: Insulin protects cardiomyocytes from apoptosis. Insulin resistance usually refers to a defect in the ability of insulin to stimulate glucose uptake. It is unknown, however, whether or not insulin resistance compromises the cell-protective effect of the hormone. Caspases are a family of cysteine proteases that regulate apoptosis. We explored the effects of insulin resistance on hypoxia-induced caspase-3 activation in cardiomyocytes. METHODS: Experiments were performed in cultured neonatal rat cardiomyocytes. Insulin resistance was induced by treating cardiac myocytes with isoproterenol, a beta-adrenergic receptor agonist. RESULTS: Twelve hours of hypoxia-induced caspase-3 cleavage, which was inhibited by treatment with insulin, while pre-treatment with isoproterenol abolished the insulin effect. Hypoxia-induced cleavage of caspase-3 was mediated by p38 mitogen-activated protein kinase (MAPK). Insulin inhibited hypoxia-induced phosphorylation of p38 through MAPK phosphatase-1 (MKP-1). Insulin-induced MKP-1 expression was mediated by extracellular signal-regulated protein kinases (ERK) 1/2, c-Jun NH2-terminal kinases (JNK) MAPK, and phosphatidylinositol 3-kinase (PI3K)/Akt pathways. Isoproterenol stimulation failed to induce expression of MKP-1; moreover, insulin resistance induced by long-term beta-adrenergic stimulation inhibited insulin-evoked expression of MKP-1 by impairing insulin-induced phosphorylation of both ERK1/2 and JNK without affecting Akt kinase activity. Furthermore, concomitant activation of Akt, ERK 1/2, and JNK was required for insulin to exert its protective effect against the hypoxia-induced cleavage of caspase-3. CONCLUSIONS: The results of this study lead to the conclusions that, in cardiac myocytes, antiapoptotic signals induced by insulin are mediated by more than one signaling pathway, and that long-term beta-adrenergic receptor stimulation impairing some of these pathways affects the cytoprotective action of insulin.

An 11-year old boy was admitted to our intensive care unit following a successfully resuscitated ventricular fibrillation (VF) cardiac arrest during mild physical activity. Six months earlier he was diagnosed with non-obstructive hypertrophic cardiomyopathy (HCM) after an ECG at a pre-sport participating screening had shown left ventricular hypertrophy, marked repolarization abnormalities, and ST depression (Figure 1). There was no family history of HCM or sudden cardiac death (SCD). The child had been completely asymptomatic before the event; specifically, he had never experienced syncopal episodes. Maximal left ventricular wall thickness on echocardiography was 18 mm (z-score 4,5) and an Echo-bike and a 24h Holter monitor had been completely unremarkable. He was on no medications.

Upregulation of the sympathetic nervous system plays a key role in the pathogenesis of insulin resistance. Although the heart is a target organ of insulin, few studies have examined the mechanisms by which β-adrenergic stimulation affects insulin sensitivity in cardiac muscle. In this study, we explored the molecular mechanisms involved in the regulation of the cross-talk between β adrenergic and insulin receptors in neonatal rat cardiomyocytes and in transgenic mice with cardiac overexpression of a constitutively active mutant of Akt (E40K Tg). The results of this study show that β-adrenergic receptor stimulation has a biphasic effect on insulin-stimulated glucose uptake. Short-term stimulation induces an additive effect on insulin-induced glucose uptake, and this effect is mediated by phosphorylation of Akt in threonine 308 through PKA/Ca 2+ -dependent and PI3K-independent pathway, whereas insulin-evoked threonine phosphorylation of Akt is exclusively PI3K-dependent. On the other hand, long-term stimulation of β-adrenergic receptors inhibits both insulin-stimulated glucose uptake and insulin-induced autophosphorylation of the insulin receptor, and at the same time promotes threonine phosphorylation of the insulin receptor. This is mediated by serine 473 phosphorylation of Akt through PKA/Ca 2+ and PI3K-dependent pathways. Under basal conditions, E40K Tg mice show increased levels of threonine phosphorylation of the β subunit of the insulin receptor and blunted tyrosine autophosphorylation of the β-subunit of the insulin receptor after insulin stimulation. These results indicate that, in cardiomyocytes, β-adrenergic receptor stimulation impairs insulin signaling transduction machinery through an Akt-dependent pathway, suggesting that Akt is critically involved in the regulation of insulin sensitivity.