Mitochondrial cardiomyopathy: a puzzle for the final diagnosis.

Hypertrophic cardiomyopathy in children has diverse causes. Mitochondrial diseases, a rare aetiology leading to cardiomyopathy in 20-40% of affected children, predominantly present as hypertrophic cardiomyopathy. Diagnosis is challenging due to inconsistent genotype-phenotype correlation, resulting in various clinical presentations. We present a case of a one-month-old infant with severe hypertrophic cardiomyopathy and cardiac tamponade. Genetic diagnosis revealed a Valyl-tRNA synthetase 2 (VARS2) gene mutation, linking it to mitochondrial encephalopathy-cardiomyopathy. This case highlights novel variants and expands the understanding of hypertrophic cardiomyopathy aetiology in infants.

Campylobacter coli Myocarditis: a case report.

We report the case of a 14-year-old male presented with raised myocardial injury biomarkers, on the workout, Campylobacter coli was identified on stool culture, treated with antibiotics with total resolution. Cardiac magnetic resonance showed interventricular septum and lateral wall hypokinesia and subepicardial delayed enhancement, with preserved ventricular systolic function. To our knowledge, this is the first report linking Campylobacter coli to myopericarditis in children.

Paediatric giant cell myocarditis: a case report.

A previously healthy 15-year-old teenage boy was admitted for fever and heart failure. Myocarditis was suspected, and endomyocardial biopsy revealed giant cell myocarditis. Immunosuppressive treatment was initiated, with excellent response. A plausible link to previous leptospirosis was identified. At 18-month follow-up, left ventricular function is normal. Only one other reported case of paediatric giant cell myocarditis had such a favourable outcome.

Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve.

Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp.

An insight into the autonomic and haemodynamic mechanisms underlying reflex syncope in children and adolescents: a multiparametric analysis.

Around 15% of children and adolescents experience at least one episode of syncope until adulthood. Excluding cardiac disease, the majority of syncopes are of reflex origin and benign in nature. In this situation, a tilt test is conducted to reproduce symptoms and to evaluate cardiovascular adaptations to orthostatism, but its mechanisms are not yet well defined. Here, we investigated haemodynamics and autonomic activity during tilt in young patients. Patients (n=113) with unexplained syncope were enrolled. Tilt followed a standard protocol without provocative agents. A positive response (fainters) was defined as a sudden development of syncope or presyncope associated with hypotension, bradycardia, or both. Haemodynamic parameters, autonomic activity, and baroreflex sensibility were evaluated. Data were analysed on baseline; immediately after tilting; on tilt adaptation; before fainting or before tilt-down for non-fainters; and on tilt-down. A total of 45 patients experienced syncope after a mean time of 18 minutes. During tilting up, fainters showed lower blood pressure and peripheral resistance values, which decreased progressively with time together with baroreflex sensibility. Sympathetic tone increased massively along time till syncope. No changes in cardiac output and heart rate were observed. Results show a strong effort of the autonomic nervous system to adapt to orthostatic stress through different magnitudes of sympathetic output, which was maximal before syncope without apparent modifications of parasympathetic tone. These changes suggest an imbalance between both branches of the autonomic nervous system, not enabling a time-progressive adaptation and leading the subject to faint.

Mitro-aortic aneurysms in children: single-centre experience and review of the literature.

OBJECTIVES: This publication aims to report the cases of four children with pseudoaneurysm of the mitral-aortic intervalvular fibrosa and carry out a review of the literature. BACKGROUND: Pseudoaneurysm of the mitral-aortic intervalvular fibrosa is a very rare anomaly in children. It can be either congenital or acquired, namely, after bacterial endocarditis or cardiac trauma. This pathology does not usually cause specific symptoms but its outcome may be potentially fatal. METHODS: We report the cases of four patients presenting with pseudoaneurysm of the mitral-aortic intervalvular fibrosa, referred for treatment in a paediatric cardiology clinic. Patient clinical notes were retrospectively reviewed for aetiology, clinical presentation, diagnostic work-up, surgical treatment, and follow-up. Literature on the subject was extensively reviewed. RESULTS: In three patients, pseudoaneurysm of the mitral-aortic intervalvular fibrosa was acquired, being secondary to bacterial endocarditis in two cases and establishing after mitral surgery in another case. The remaining patient had a "congenital" aetiology - no other cause could be traced. The diagnosis was achieved by transthoracic echocardiography for all patients, and confirmed in all by trans-oesophageal echocardiography, to better define morphological details and to access flow into the aneurysmal formation. All patients were submitted to corrective cardiac surgery. Of the patients, three survived and were cured by surgery, staying asymptomatic, and one died after repeated interventions, for persistent endocarditis. CONCLUSIONS: Pseudoaneurysm of the mitral-aortic intervalvular fibrosa is a rare but potentially fatal anomaly. In our experience, surgical cure was achieved for the majority of the cases, except for a case for which infection could not be locally eradicated, leading to multiple reinterventions.

The TANGO2 disease and the therapeutic challenge of acute arrhythmia management: a case report.

Background: TANGO2-related metabolic encephalopathy and arrhythmia are a rare, newly recognized, and likely under-diagnosed condition. First described in 2016, it is characterized by developmental delay and recurrent metabolic crisis. During these episodes, patients may present QTc prolongation and ventricular arrhythmias. Case summary: A 13-year-old female, with developmental delay, presented with severe rhabdomyolysis and an initially normal electrocardiogram (ECG). Due to the worsening of rhabdomyolysis, QTc prolongation was identified (QTc 570 ms) and oral ß-blocker therapy started. A non-sustained ventricular tachycardia developed, initially managed with magnesium and lidocaine. After a short period, an arrhythmic storm of polymorphic ventricular extrasystoles induced Torsade de Pointes (TdP) was triggered. A temporary percutaneous pacing lead was placed and esmolol infusion started. The electrical instability ran in parallel with the increasing severity of rhabdomyolysis and systolic ventricular function decline. Genetic testing identified a pathogenic variant in homozygosity in the TANGO2 gene. A stable sinus rhythm was achieved with metabolic and serum electrolytes optimization. ECG showed normalization of the QTc interval. Discussion: The full TANGO2-related phenotype emerges over time and the prognosis is linked to the appearance of ECG abnormalities. QT interval prolongation can lead to life-threatening ventricular tachycardias. The arrhythmia mechanism seems to be secondary to metabolite build-up in cardiomyocytes, which can explain the cardiac phenotype during the crisis which subsides after their resolution. In these patients, avoiding bradycardia is fundamental, since long QT-related TdP seems to be triggered by bradycardia and short-long-short ventricular premature beats (VPB). During an acute metabolic crisis, the management of arrhythmias relies on metabolic control.

Mechanical circulatory support in children: Strategies, challenges and future directions.

INTRODUCTION: The use of mechanical circulatory support (MCS) in the pediatric population has evolved significantly in the past 20 years, but its management still poses several challenges. We aim to describe patient characteristics, outcomes, and morbidity associated with different modalities of MCS, in a tertiary center. METHODS: Retrospective analysis of data from all the children who underwent MCS between 2002 and 2018 at a pediatric cardiology unit. RESULTS: Between 2002 and 2018, 22 devices were implanted in 20 patients. Patients were divided into three groups: Group A (n=11) extracorporeal membrane oxygenator (ECMO); Group B (n=8) pulsatile paracorporeal ventricular assist device (VAD) and group C (n=3) paracorporeal continuous flow VAD. The median age was similar in groups A and B (18 and 23 months, respectively), and higher in group C (13 years). ECMO patients were cannulated mainly as a bridge to recovery (post cardiotomy- 8) while group B and C patients were bridged to transplantation. The most frequent complications were bleeding (group A - 36%, group C - 66.6%) and thromboembolic events (group B - 50%, group C - 33.3%). As for outcomes, in group A the majority of patients (54.5%) were weaned and 27.3% died. Half of group B and all of group C patients underwent transplantation. CONCLUSION: Bleeding and thromboembolic events were the main complications observed. Group B showed the highest mortality, probably related to the low weight of the patients. Overall, outcomes and complications are related to the type of device and patient status and characteristics.

Protocol-based cardiotoxicity monitoring in hydroxychloroquine medicated COVID-19 pediatric patients.

INTRODUCTION/OBJECTIVES: By May 2020, SARS-CoV-2 had caused more than 400 000 deaths worldwide. Initially, hydroxychloroquine was a treatment option for COVID-19. More recent studies have questioned its safety and efficacy and, until stronger evidence is available, it was suspended from therapy protocols. We describe our experience treating COVID-19 Portuguese pediatric patients with hydroxychloroquine, having applied a protocol for monitoring cardiac toxicity. METHODS: An observational retrospective study of COVID-19 pediatric patients, admitted from March to April 2020 and treated with hydroxychloroquine. Cardiotoxicity was assessed using ECG recordings and corrected QT-time (QTc). Patients were classified into risk-groups depending on QTc value: normal, slightly elevated or severely elevated (>500 ms). RESULTS: Total of 14 patients, with a median age of 10 years [four months; 17 years], treated with hydroxychloroquine for a median of five days. Hydroxychloroquine was used in monotherapy in six patients (mainly mild disease with comorbidities), and in association with lopinavir/ritonavir (3) and azithromycin (5) in moderate to severe disease. Other QT-prolonging therapies were used in five patients: oseltamivir (3), omeprazole (1), morphine (1) and ketamine (1). At 48 hours of treatment, two patients temporarily suspended hydroxychloroquine due to QTc prolongation (>500 ms). All patients completed the whole treatment. No other side effects or deaths occurred. CONCLUSION: Clinical trials are evolving to define hydroxychloroquine effectivity and safety. Our considerable pediatric population supports the need for cardiotoxicity monitoring during therapy but suggest its use seems to be safe in COVID-19 pediatric patients, even in association with other QT-prolonging therapies.

INTRODUÇÃO/OBJETIVO: A hidroxicloroquina foi inicialmente uma das opções terapêuticas na Covid-19. Descreve-se o tratamento com hidroxicloroquina em doentes Covid-19 pediátricos, tendo aplicado um protocolo de monitoração cardíaca pelo seu potencial arritmogénico. MÉTODOS: Estudo observacional retrospetivo de doentes pediátricos com Covid-19, internados de março a abril 2020, medicados com hidroxicloroquina. A monitoração cardíaca foi realizada por eletrocardiogramas regulares e cálculo do intervalo QT corrigido durante o tratamento. Os doentes foram classificados consoante o valor de QTc: normal, moderadamente aumentado ou muito aumentado (>500 msg). RESULTADOS: Total de 14 doentes, com mediana de 10 anos [4 meses; 17 anos], medicados com HCQ durante uma mediana de 5 dias em doentes com pneumonia ou comorbilidades. A monoterapia foi realizada em 6 doentes, 4 com fatores de risco, e em associação com lopinavir/ritonavir (3) e azitromicina (5) na doença grave e moderada. Foram ainda usados fármacos capazes de prolongar o intervalo QT: oseltamivir (3), omeprazol (1), cetamina e morfina (1) em 5 doentes. Após 48 horas de terapêutica, dois doentes apresentaram intervalo QTc muito aumentado, condicionando suspensão temporária do fármaco. Todos os doentes concluíram o tratamento sem outros efeitos adversos. CONCLUSÃO: A HCQ permanece em ensaios clínicos para avaliação da sua efetividade e segurança. A nossa amostra considerável em doentes pediátricos apoia a necessidade de monitoração de toxicidade cardíaca, mas sugere na população estudada, mesmo na associação com outros fármacos que prolongam o intervalo QT, a segurança de sua utilização.

[Quadricuspid aortic valve--10-year case series and literature review]. / Válvula aórtica quadricúspide--casuística de 10 anos e revisão da literatura.

INTRODUCTION: Quadricuspid aortic valve is a rare malformation, with an estimated incidence of 0.003 to 0.043% of all congenital heart disease. It usually appears as an isolated congenital anomaly, but may also be associated with other malformations, the most common being coronary artery anomalies. Current technology enables noninvasive diagnosis in most cases. This entity's natural history is progression to valve regurgitation, which is rare before adulthood. OBJECTIVE: Case review of quadricuspid aortic valve patients diagnosed in the last 10 years in a tertiary pediatric cardiology center. METHODS: Retrospective chart review of patients diagnosed with quadricuspid aortic valve between January 2000 and December 2009. RESULTS: Over the past 10 years, four cases of quadricuspid aortic valve were diagnosed in children aged between 6 months and 8 years, two male. In three cases, the four leaflets were of similar size, which is the most common finding. Two of the valves functioned normally and two had minimal regurgitation. All patients had associated cardiac malformations (one atrial and two ventricular septal defects, one supravalvular aortic stenosis and one quadricuspid pulmonary valve). One patient was also diagnosed with Williams syndrome. During a median follow-up of 2 years (0-9), all patients remained asymptomatic and none required medical or surgical treatment of the aortic valve. CONCLUSION: Diagnosis of quadricuspid aortic valve is rare, especially in children, since most patients are asymptomatic and have normally functioning valves. In this study, half the patients had minimal aortic regurgitation. Contrary to what is described in the literature, all patients had concomitant cardiac malformations. We provide the first description of this entity's association with Williams syndrome. Clinical follow-up should be maintained in these patients in order to promptly detect the onset or worsening of functional alterations and to enable appropriate therapeutic intervention.

ROSS SURGERY: OUR EXPERIENCE.

OBJECTIVES: At Santa Marta Hospital, Ross Surgery was performed for the first time in 1999. Twenty years later, we feel it is desirable to evaluate the mid and long-term results of our experience, as well as estimate the future of this procedure. METHODS: Between March 1999 and June 2016, 23 Ross procedures were performed at our institution. We did a retrospective analysis of the patients´ data, results of the surgery, complications, freedom from reoperation and mortality. RESULTS: The majority (36,4%) of the patients had aortic stenosis, 22,7% had aortic regurgitation and 27,3% had aortic stenosis and regurgitation. Sub-valvular stenosis was present in 13,6% of patients. The mean follow-up is 15 years. The overall mortality was 9%, without early mortality. In our series, 83% of the patients are free from reoperation. Eighty percent (n=16) of the survivors are in NYHA class I, with the remaining 20% (n=4) in class II. CONCLUSION: Ross surgery has strict indications and in this group of patients the advantages are undeniable and the outcomes, according to our results (with 83% of patients free from reoperation, at a mean follow-up of 15 years), are positive and encouraging.

Quality of life among adults with repaired tetralogy of fallot: A literature review.

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. Survival into adulthood is currently expected following surgical repair, leading to a growing population of adults with repaired TOF. In this literature review, we aim to summarize the current state of knowledge on the quality of life of adults with repaired TOF. A search was conducted on PubMed and results were reviewed for articles published between January of 2010 and June of 2020. Search terms included "Tetralogy of Fallot", "repaired", "adults" and "quality of life". For the subjective health status evaluation, most published studies used Short-Form-36. Most studies agree that physical complex status is poorer for adult patients with repaired TOF than for controls. Mental complex status was also lower. Patients reported similar satisfaction with their lives and levels of social participation. Most patients had a college or university degree. Higher education, male gender and having a partner were positively associated with being employed. Studies found no difference in the proportion of patients that are married or living with a partner, compared to control groups. Patients operated for TOF have a lower reproduction rate compared with the background population. A consistent finding of these studies is abnormal physical parameters compared to psychosocial issues. The diverse needs of adults with repaired TOF require a multidisciplinary care, that takes into consideration all aspects that affect their quality of life. Despite abnormal physical functional status, it is reassuring that most adult patients with TOF lead independent and productive lives.

Percutaneous pulmonary valve implantation: initial experience.

INTRODUCTION: Patients with congenital heart disease who undergo surgical implantation of a conduit between the right ventricle and the pulmonary artery (RV-PA conduit) may develop stenosis and/or insufficiency over time. These cases, which are associated with arrhythmias, RV dysfunction and sudden death, remain a challenge for surgical re-intervention, due to its complexity and associated morbidity and mortality. Percutaneous pulmonary valve implantation (PPVI) is therefore a valid alternative. OBJECTIVE: To report our center's initial experience with PPVI. METHODS: Prospective assessment of clinical, echocardiographic, magnetic resonance, hemodynamic and angiographic data from our series of PPVI. RESULTS: Six patients in NYHA functional class +/- II underwent PPVI. All had significant conduit dysfunction and five had stenosis. The procedure consisted of implanting a bare metal stent to reduce the risk of fracture of the Melody valved stents (Medtronic) that were then successfully deployed in all. The immediate hemodynamic results showed a reduction in RV pressure (94 +/-27 to 44 +/- 7 mmHg), RV/LV pressure ratio (94 +/-27 to 44 +/- 7%) and conduit gradient (65 +/- 28 to 11 +/- 4 mmHg), and no insufficiency. The median duration of the procedure was 180 minutes, with no major complications. Patients were discharged a median of two days after the procedure. After a median follow-up of 7.8 months, patients are in functional class I (5) or II (1), with no evidence of conduit dysfunction on non-invasive assessment. CONCLUSIONS: Our results are similar to the excellent results reported in larger series. PPVI is a valid therapeutic option in patients with conduit dysfunction.

Isolated aortic coarctation: experience in 100 consecutive patients.

INTRODUCTION: Coarctation of the aorta (CoA) is a stenosis usually located in the descending aorta. Treatment consists of surgical or percutaneous removal of the obstruction and presents excellent immediate results but significant residual problems often persist. OBJECTIVES: To describe the presentation, treatment and long-term evolution of a population of 100 unselected consecutive patients with isolated CoA in a single pediatric cardiology center. METHODS: This was a retrospective study of all patients with isolated CoA treated during4 the last 21 years (1987-2008). RESULTS: The patients (n=100, 68.3% male) were diagnosed at a median age of 94 days (1 day to 16 years). The clinical presentation differed between patients aged less or more than one year, the former presenting with heart failure and the latter being asymptomatic with evidence of hypertension (88 and 63%, respectively; p < 0.01). Treatment, a median of 8 days after diagnosis, was surgical in 79 cases (20 end-to-end anastomosis, 31 subclavian flap, 28 patch) and percutaneous in the remaining 21 (15 balloon angioplasty, 6 with stenting). The mean age of surgical patients was younger than in those treated percutaneously (3.4 vs. 7.5 years; p < 0.01). Immediate mortality was 2% and occurred in the surgical group. There was no late mortality, in a mean follow-up of 7.2 +/- 5.4 years. Recoarctation occurred in 8 patients (6 surgical, 2 percutaneous). There are 46 patients who currently have hypertension (19 at rest, 27 with effort), their median age at diagnosis being older than the others (23 vs. 995 days; p < 0.01). CONCLUSIONS: Isolated CoA has an excellent short-term prognosis but a significant incidence of long-term complications, and should thus no longer be seen as a simple obstruction in the descending aorta, but rather as a complex pathology that requires careful follow-up after treatment. Its potentially insidious presentation requires a high level of clinical suspicion, femoral pulse palpation during physical examination of newborns and older children being particularly important. Delay in treatment has an impact on late morbidity and mortality. Taking into account the data currently available on late and immediate results, the final choice of therapeutic technique depends on the patient's age, associated lesions and the experience of the medical-surgical team. Hypertension should be closely monitored in the follow-up of these patients, as well as its risk factors and complications.

Cardiac tumors: the 17-year experience of pediatric cardiology department.

INTRODUCTION: Primary cardiac tumork may be benign or malignant and may arise anywhere in the endocardium, myocardium or pericardium. They are rare in pediatric age-groups, with a prevalence in autopsy findings of 0.0017 to 0.28%; most are benign, malignant tumors accounting for only 10% of the total. OBJECTIVE AND METHODS: The purpose of this paper is to report the 17-year (1989-2006) experience of primary cardiac tumors in a single center. The clinical data and histopathological diagnoses were collected from a retrospective chart review. RESULTS: We identified 12 patients, with a mean age at diagnosis of 23 months, in two cases diagnosed in the fetal period. The frequent cause of referral was tuberous sclerosis, followed by a cardiac murmur. The diagnosis of primary cardiac tumor was based on echocardiography and/or magnetic resonance imaging. The patients all underwent 24-hour electrocardiographic Holter monitoring, and the most common finding was nonspecific repolarization abnormalities. The most frequent cardiac tumor was rhabdomyoma (67%), usually associated with tuberous sclerosis, followed by fibroma (17%) and fibroelastoma (8%) Although biopsy is the diagnostic gold standard, it was only performed in two patients. Surgical removal of the tumor was performed in a single patient (with fibroelastoma) due to the perceived risk of pulmonary embolization. DISCUSSION AND CONCLUSIONS: In our population, the most frequent tumor was rhabdomyoma associated with tuberous sclerosis. Most patients were asymptomatic, and the diagnosis was made in routine observations on patients with tuberous sclerosis or with a cardiac murmur. A histopathological diagnosis is only warranted in the rarest forms of cardiac tumors.

Octreotide--additional conservative therapy for postoperative chylothorax in congenital heart disease.

INTRODUCTION: Chylothorax is a rare but serious postoperative condition in children with congenital heart disease. Conventional medical treatment consists of specific long-term dietary modification, and surgical reintervention, such as lymphatic duct ligation, may be indicated in refractory cases. In recent years, an additional conservative treatment, octreotide, a synthetic analog of somatostatin, has been used in management of congenital and postoperative chylothorax. METHODS: The objective of this work was to analyze the efficacy and safety of this treatment for chylothorax after congenital heart surgery. We reviewed the records of sixteen patients with chylothorax after surgery for congenital heart disease between January 1999 and December 2007, and collected the following data: demographic information; type of surgical procedure; onset, duration and management of chylothorax and treatment; and duration of hospital stay. To analyze efficacy we compared these parameters in children receiving conventional treatment only with those receiving octreotide. To analyze safety we compared the adverse effects of both treatments. Octreotide was administered at a dose of 4 to 10 microg/kg/hour, with monitoring of side effects. RESULTS: The incidence of chylothorax in our population was 1.6%. It occurred more often after Glenn and Fontan procedures (8 patients). Octreotide was begun three days after diagnosis of chylothorax and continued for a median of seventeen days (ranging from 4 to 26 days), until complete resolution. Side effects were frequent (in 3 of the 8 patients) but of no clinical relevance. All patients responded to the therapy and there was no indication for further surgical intervention. DISCUSSION AND CONCLUSIONS: Octreotide is safe and effective in the treatment of postoperative chylothorax in children with congenital heart disease. It is a useful adjunctive therapy to the conventional treatment of this complication.

Pericarditis - Clinical presentation and characteristics of a pediatric population. / Pericardite ­ apresentação e características numa população pediátrica.

INTRODUCTION: Pericarditis is an inflammation of the pericardium. It may be infectious or secondary to a systemic disease. The aim of this study was to analyze the clinical findings, course, treatment and follow-up of children diagnosed with pericarditis at our center. METHODS: We performed a retrospective analysis of all children admitted to our pediatric cardiology unit with pericarditis between 2003 and 2015. Patient characteristics were summarized using frequencies and percentages for categorical variables and medians with percentiles for continuous variables. RESULTS: Fifty patients were analyzed (40 male, 10 female) with a median age of 14 years. The most common diagnosis was acute pericarditis (80%). Thirty-five patients (70%) presented with chest pain and 26% reported fever. Cardiomegaly was identified on chest X-ray in 11 patients (22%), 30 patients (60%) had an abnormal ECG and 44 patients (80%) had alterations on the transthoracic echocardiogram. In 17 cases (34%) there was myocardial involvement. Forty-eight percent of patients presented with infectious pericarditis and the pathologic agent was identified in half of them. Postpericardiotomy syndrome was diagnosed in five cases. The first-line therapy was aspirin in 50% of cases. Pericardiocentesis was performed in 12 patients. The median length of stay was nine days. There was symptom recurrence in seven children. CONCLUSIONS: In this study, acute infectious pericarditis was the most common presentation and about one third of patients also had myocarditis. The symptom recurrence rate was not negligible and is probably related to the type of therapy employed.

Clinical and genetic diagnosis of familial hypertrophic cardiomyopathy: Results in pediatric cardiology. / Diagnóstico clínico e genético de miocardiopatia hipertrófica familiar: resultados em cardiologia pediátrica.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) is most often of autosomal dominant inheritance with incomplete penetrance and variable expression. The main purpose of family screening is to identify relatives with unrecognized HCM and to monitor those at risk for disease, in order to minimize complications and to assess risk of sudden cardiac death. The ESC and ACCF/AHA guidelines on the diagnosis and management of HCM recommend the screening of child relatives from the age of 10-12 years. OBJECTIVES: We studied the outcome of clinical screening and genetic testing of child probands and relatives (<18 years of age) from families with HCM and assessed the age-related penetrance of HCM during the follow-up of these young relatives. METHODS AND RESULTS: Twenty patients from ten families were included between 2004 and 2013, consisting of three probands and 17 first-degree relatives (80% male; median age 10 years). Fourteen child relatives were mutation carriers (70%; median age eight years). Seven (50%) of the 14 mutation carriers were diagnosed with HCM at initial assessment. At-risk child relatives were defined as those with a positive mutation but a negative phenotype at enrollment. After 3.5±0.8 years of follow-up, two of the phenotype-negative mutation carriers developed HCM at 10 and 15 years of age (28% penetrance rate). CONCLUSIONS: The penetrance of HCM in phenotype-negative child relatives was 28% after 3.5 years of follow-up. This underlines the need for long-term monitoring of mutation carriers irrespective of the presence of a positive phenotype.

Sotalol in the treatment of fetal tachyarrhythmia.

BACKGROUND: Fetal tachycardia is an uncommon condition that if sustained may lead to fetal death. There is no consensus regarding the optimum treatment. The aim of this study was to evaluate the safety and efficacy of sotalol in the treatment of fetal tachycardia. METHODS: This was a retrospective study of patients treated for fetal tachycardia with sotalol in a pediatric cardiology department over a ten-year period. RESULTS: There were eight fetuses treated for supraventricular tachycardia and sotalol was used in six of them. Mean gestational age was 30 weeks. None of them had congenital heart disease; two fetuses had hydrops and one had hydrocephalus. All had supraventricular tachycardia and two had atrial flutter. Drug treatment was successful in establishing sinus rhythm in five of the six fetuses treated with sotalol and no adverse effects were recorded in the mothers. There were no deaths. Supraventricular tachycardia was present in three infants at birth. CONCLUSIONS: In this study sotalol was successful and safe in the treatment of fetal tachycardia, but given the small sample size, more studies are needed to validate this conclusion.