Controversies in arrhythmias and arrhythmic syndromes of active children and young adults

Important advances in the diagnosis and therapy of various arrhythmic disorders have been made in the last two decades. These, in turn, have necessitated a re-examination of current practice guidelines, with a view to deciding on optimal management of young patients with suspected or proven arrhythmia syndromes and in assessing the risk of adverse arrhythmic events during sport participation. There has also been a concomitant emphasis on identifying individuals at risk by nationwide screening programs using the ECG and excluding them from competitive sport. This review identifies some of these issues, looks at the data critically and offers some suggestions for current care and future research

The pathophysiologic aspects and clinical implications of electrocardiographic parameters of ventricular conduction delay in repaired tetralogy of Fallot

The 12-lead surface electrocardiograni is a valuable and feasible clinical tool in the management of patients following tetralogy of Fallot (TOF) repair. The importance of QRS duration in TOF patients has long been acknowledged. A prolonged QRS complex has been associated with increased risk for subsequent life-threatening ventricular arrhythmia and sudden cardiac death. Our current ability to risk-stratify TOF patients for malignant arrhythmogenic events primarily on the basis of QRS duration is rather limited. Nevertheless, increasing evidence suggests that QRS morphology and duration may be useful as surrogate markers of infundibular and regional right ventricular myocardial disease. The aim of this review is to provide a critical appraisal of the clinical implications of established and new electrocardiographic markers of ventricular conduction delay in TOF patients following surgical correction with a particular focus on QRS duration, lengthening, and fragmentation. In addition, the pathophysiological background of these parameters is addressed. (C) 2014 Elsevier Inc. All rights reserved

Use of an active fixation lead and a subpectoral pacemaker pocket may not avoid Twiddler′s syndrome

Manipulation of a pacemaker with consequent malfunction of the device has been called Twiddler′s syndrome. Use of active-fixation leads and subpectoral pacemaker pockets has been considered to help in avoiding this problem. We describe a child in whom twiddling was not prevented despite implantation of a lumenless atrial lead and insertion of the pacemaker generator in a subpectoral pocket

Emerging clinical applications of strain imaging and three-dimensional echocardiography for the assessment of ventricular function in adult congenital heart disease

Management of congenital heart disease (CHD) in adults (ACHD) remains an ongoing challenge due to the presence of residual hemodynamic lesions and development of ventricular dysfunction in a large number of patients. Echocardiographic imaging plays a central role in clinical decision-making and selection of patients who will benefit most from catheter interventions or cardiac surgery.. Recent advances in both strain imaging and three-dimensional (3D)-echocardiography have significantly contributed to a greater understanding of the complex pathophysiological mechanisms involved in CHD. The aim of this paper is to provide an overview of emerging clinical applications of speckle-trading imaging and 3D-echocardiography in ACHD with focus on functional assessment, ventriculo-ventricular interdependency, mechanisms of electromechanical delay, and twist abnormalities in adults with tetralogy of Fallot (TOF), a systemic RV after atrial switch repair or in double discordance ventricles, and in those with a Fontan circulation

Disease control via intensified lipoprotein apheresis in three siblings with familial hypercholesterolemia

BACKGROUND: Familial hypercholesterolemia (FH), the prevalent monogenic form of hypercholesterolemia, carries the risk of premature coronary heart disease. Lipoprotein-apheresis is established in children with severe dyslipidemia. We present 3 siblings with a negative/negative residual low density lipoprotein (LDL) receptor mutation (p.Trp577Arg), unresponsive to drug treatment. OBJECTIVE: Intensified lipoprotein-apheresis is well tolerated and results in permanently low lipid values without harming the health-related quality of life in children. METHODS: Three homozygous FH siblings, aged 7-13 years, had been treated with statins and ezetimibe for 12 months but still showed highly elevated low-density lipoprotein cholesterol (LDL-C) plasma concentrations. They were started on double-filtration plasmapheresis that was subsequently intensified according to plasma lipid levels. RESULTS: Each lipoprotein apheresis session reduced LDL-C concentration by 66% to 70%. Treated plasma volume was doubled after 6 months due to a sustained rebound of LDL-C between sessions. However, the rebound remained unchanged. Only an increase in frequency of sessions to every 3 to 4 days resulted in acceptable pre-treatment LDL-C concentrations (Cmax). Neither cessation of statins nor reduction of plasma exchange volume to 1.5 fold in follow-up influenced Cmax. Intensified therapy did not harm health-related quality of life as assessed by PedsQL and was well tolerated. CONCLUSIONS: In pediatric FH patients unresponsive to drug treatment, intensified lipoprotein apheresis can normalize plasma lipid levels. Apparently, treatment frequency rather than volume has greater influence on its efficacy. The potential burden of intensified therapy to daily life has to be regarded. Serum lipid levels in FH should be normalized to minimize cardiovascular risk. (C) 2016 National Lipid Association. All rights reserved

Stenting the Fontan pathway in paediatric patients with obstructed extracardiac conduits

Objectives An unobstructed extracardiac conduit (ECC) is essential for optimal Fontan haemodynamics. We aimed to evaluate the feasibility and results of percutaneous transcatheter stenting of the ECC in paediatric patients with a significant Fontan pathway obstruction. Methods Our institutional database was searched to identify all Fontan patients who had a stent placed in their ECC. Medical records, cardiac catheterisation data and echocardiographic investigations were reviewed. Vessel diameters were normalised to account for differences in body surface area. Results Nineteen Fontan patients (age 6.5+/-3.2 years; male 78.9%) with a significant stenosis of their Dacron ECC graft were identified. Seven patients presented with protein-losing enteropathy (36.8%). An ECC obstruction was suspected on echocardiography in only 6/19 patients (31.6%). The mean minimum diameter of the ECC was 8.3+/-2.4 mm. A stenosis of >45% was seen in the majority of patients (n=12, 63.1%). Significant correlations between the severity of the ECC obstruction and Fontan pathway vessel diameters were found (all p<0.05). Stenting was successful in all children. The ECC diameter increased significantly after stenting (p<0.0001). An acute clinical benefit of ECC stenting was observed in 18/19 (94.7%) patients. ECC patency was good during a mean follow-up of 1.8+/-0.9 years. Conclusions The feasibility and acute results of percutaneous transcatheter ECC stenting are promising and may provide a good alternative to postpone surgery to a later age. The mechanisms contributing to the development of ECC stenoses are likely multifactorial