Sudden cardiac arrest in children and young athletes: the importance of a detailed personal and family history in the pre-participation evaluation.

Healthcare providers have become more aware of and concerned about paediatric sudden cardiac arrest. The diseases predisposing a patient to sudden cardiac arrest are all infrequently encountered. However, a detailed and comprehensive patient and family history may reveal warning signs and symptoms that identify a patient at higher risk for sudden cardiac arrest. Since many of these diseases are genetic, extensive family evaluation may uncover a previously undetected cardiac disease process and as well direct the development of a complete family evaluation and treatment plan. Published data document that in many cases preceding warning symptoms and signs are present, but may be misinterpreted or disregarded by medical staff. Attention to the details of patient history, family history and physical exam is critical to the success of any detection strategy, which can and should be widely applied.

Presentation of atrial septal defect in the pediatric population.

Our recent experience indicates that patients with a hemodynamically significant atrial septal defect secundum (ASD2) do not necessarily present with classic physical and electrocardiographic (ECG) findings. The purpose of the study was to review the records of patients either receiving a catheter device or undergoing surgical repair for the closure of ASD2 to determine their initial physical and ECG findings. Therefore, we did a retrospective review of 47 consecutive patients who had echocardiographic evidence of a hemodynamically significant isolated ASD2 and who underwent ASD2 closure. Of these 47 patients, the presenting complaints were murmur (n = 36), chest pain (n = 6), seizure (n = 1), stroke (n = 1), syncope (n = 1), Kawasaki's disease (n = 1), and cardiomegaly (n = 1). Charts were reviewed for the evaluation of four abnormal physical findings: hyperactive right ventricular impulse, split fixed second heart sound, systolic and diastolic flow murmurs; and three ECG abnormalities: right axis deviation, right atrial enlargement, and evidence of right ventricular hypertrophy. In all, 30% of patients had either one or no typical physical findings, 18% had normal ECG findings, and 7% had no physical or ECG findings. On physical examination and ECG, the abnormalities due to ASD2 may be too subtle to detect. Although it is well known that variations can occur in the clinical signs and symptoms typical of ASD2, dependence on classical physical and or ECG findings may result in the underdiagnosis of a significant number of patients.

[New treatment concept for children with thoracic insufficiency syndrome due to congenital spine deformity]. / Neues Therapiekonzept für Kinder mit Thoraxinsuffizienz-Syndrom aufgrund von Wirbelsäulenfehlbildungen.

BACKGROUND: Children with congenital thoracic scoliosis associated with fused ribs and unilateral unsegmented bars adjacent to convex hemivertebrae will inevitably develop thoracic insufficiency syndrome and curve progression with hemithorax compression without treatment. It is assumed that the concave side of such curves and their unilateral unsegmented bars do not grow. In the past early spinal fusion was performed with consecutive short thoracic spines and loss of lung volume. Little attention has been paid to lung function. These patients often suffered from lung failure and early death due to a small thorax. METHOD: A new surgical technique is based on an indirect deformity correction and enlargement of the thorax due to a longitudinal implant, the vertical expandable prosthetic titanium rib (VEPTR). The spine is not fused, thus promoting growth of the spine, the thorax and the lungs. Elongation of the implant is done every six months. Since 2002 this method has been performed on fifteen children in Basel as the first European center. RESULTS: Patients (mean age 6 years; 11 months to 12 years) were suffering from thoracic insufficiency syndrome due to unilateral unsegmented bars with fused ribs (n = 4), absent ribs (n = 2), bilaterally fused ribs (n = 2), hemivertebrae (n = 3) or neuromuscular scoliosis (n = 6). Doing fifteen primarily implantations and thirteen elongations there were three complications (two hook dislocations, one skin breakage). All patients improved cosmetically, functionally and radiologically which was shown on X-rays as a reduction of the Cobb angle from an average of 76 degrees (40-110 degrees ) to 55 degrees (30-67 degrees ). CONCLUSIONS: Expansion thoracoplasty and VEPTR implantation is a new treatment concept for children with thoracic insufficiency syndrome due to spinal deformities, which is based on distraction and expansion of the thorax thus allowing growth of the spine, the thorax and probably lungs. Presently it seems to be superior to any other method for the treatment of small children with progressive scoliosis and thoracic insufficiency syndrome.

Quantifying and minimizing radiation exposure during pediatric cardiac catheterization.

This study reports findings from evaluations of new technologies to measure radiation exposure during pediatric cardiac catheterization procedures. A strategy of pulsed fluoroscopy and low power settings resulted in significantly lower patient radiation exposure compared to conventional 60 frames/sec, high-power settings during fluoroscopy. During radiofrequency ablation procedures, thyroid and thoracic skin sites outside the direct fluoroscopic field received minimal radiation exposure. Intrathoracic radiation exposure was measured with the use of an esophageal dosimeter. In conclusion, strategies to reduce total radiation exposure should be employed, radiation dose should be measured, and assessment of radiation skin injury should be included in post-catheterization assessment.

[Treatment of congenital scoliosis with the vertical expandable prosthetic titanium rib implant]. / Behandlung der kongenitalen Skoliose mit dem Vertical-expandable-prosthetic-titanium-rib-Implantat.

Children with congenital thoracic scoliosis associated with fused ribs and unilateral unsegmented bars adjacent to convex hemivertebrae will invariably have curve progression without treatment. It is assumed that the unilateral unsegmented bars do not grow and therefore early spinal fusion has been performed in the past with consecutive short thoracic spines and loss of lung volume. A new surgical technique is based on an indirect deformity correction and enlargement of the thorax via a longitudinal implant, the vertical expandable prosthetic titanium rib (VEPTR). The length of the thoracic spine after VEPTR implantation was analyzed in 21 children with an average follow-up of 4.2 years. Eighteen children did not have any prior surgery while three had already undergone spinal fusion. Using a 3-D analysis of computed tomography, a significant growth of the concave (7.9 mm/7.1% increase per year) and convex (8.3 mm/6.4%) side of the thoracic spine was found with no significant difference between sides. Unilateral unsegmented bars showed significant growth as well. Contrary to common knowledge, we were able to demonstrate the growth of the concave side of the thoracic spine and of the unilateral unsegmented bars after expansion thoracoplasty and VEPTR implantation.

The role of radiofrequency ablation for pediatric supraventricular tachycardia.

Radiofrequency ablation has become frontline therapy for many pediatric patients with common supraventricular tachycardia (SVTs). Rather than long-term treatment with medications, radiofrequency ablation offers the possibility of "cure" for certain SVT substrates. The decision to perform radiofrequency ablation should be made after full disclosure with the patient and parents about radiofrequency ablation (RFA) benefits and risk, alternative therapies, and the natural history of the SVT. This paper presents a discussion about the current status of RFA and common pediatric SVTs, as well as, discussing evolving RFA issues and indications.

Association of parental psychological and behavioral factors and children's syncope.

The authors examined the associations between parental variables and child syncope (fainting). Children ages 7 to 18 years undergoing tilt-table testing for neurocardiogenic syncope (NCS) at a pediatric cardiac center served as participants (N = 56). Results revealed that fathers' shortness of breath and overall psychological distress were significantly related to syncope frequency and emergency room (ER) visits for girls. Mothers' overall psychological distress, depressive symptoms, and shortness of breath were associated with boys' frequency of syncope and ER visits. Fathers' psychological factors were highly correlated with syncope for the children diagnosed negative for NCS. The frequency of children's syncope was higher in stepfamilies than in homes with both biological parents, and the correlations between children's syncope and the stepfathers' psychological symptoms were greater than for the children and their biological fathers in intact families. The role of parental psychological factors on child syncope is supported.

Chylopericardium after cardiac operations in children.

BACKGROUND: Chylopericardium is a rare complication after operation for congenital heart disease. The incidence and clinical outcomes in a large cohort of surgical patients are unknown. METHODS: We retrospectively reviewed the clinical records spanning more than 12 years in a single institution of 16 children with chylopericardium after cardiac operation. RESULTS: We identified 16 patients with chylopericardium between 1985 and 1997. Chylopericardium was isolated in 7 patients. Twelve patients required pericardial drainage. Patients with isolated chylopericardium presented late and were treated initially as having postpericardiotomy syndrome. Three patients underwent thoracic duct ligation. There were two late deaths unrelated to the chylothorax. Associated diagnoses were internal jugular vein thrombosis and recurrent pulmonary vein obstruction (1 of 16 patients), an associated syndrome but not Turner or Noonan (10 of 16), superior cavopulmonary or total cavopulmonary anastomosis (7 of 16), atrioventricular septal defect repair (5 of 16), and repair of tetralogy of Fallot (2 of 16). CONCLUSIONS: Percutaneous drainage to relieve tamponade together with a low-fat or medium-chain triglyceride diet results in resolution in most cases of postoperative chylopericardium. If a pericardial effusion enlarges, fails to clear on aspirin therapy, or presents late after hospital discharge, diagnostic pericardial tap and a low-fat diet are indicated.

Modeling human congenital disorder of glycosylation type IIa in the mouse: conservation of asparagine-linked glycan-dependent functions in mammalian physiology and insights into disease pathogenesis.

The congenital disorders of glycosylation (CDGs) are recent additions to the repertoire of inherited human genetic diseases. Frequency of CDGs is unknown since most cases are believed to be misdiagnosed or unrecognized. With few patients identified and heterogeneity in disease signs noted, studies of animal models may provide increased understanding of pathogenic mechanisms. However, features of mammalian glycan biosynthesis and species-specific variations in glycan repertoires have cast doubt on whether animal models of human genetic defects in protein glycosylation will reproduce pathogenic events and disease signs. We have introduced a mutation into the mouse germline that recapitulates the glycan biosynthetic defect responsible for human CDG type IIa (CDG-IIa). Mice lacking the Mgat2 gene were deficient in GlcNAcT-II glycosyltransferase activity and complex N-glycans, resulting in severe gastrointestinal, hematologic, and osteogenic abnormalities. With use of a lectin-based diagnostic screen for CDG-IIa, we found that all Mgat2-null mice died in early postnatal development. However, crossing the Mgat2 mutation into a distinct genetic background resulted in a low frequency of survivors. Mice deficient in complex N-glycans exhibited most CDG-IIa disease signs; however, some signs were unique to the aged mouse or are prognostic in human CDG-IIa. Unexpectedly, analyses of N-glycan structures in Mgat2-null mice revealed a novel oligosaccharide branch on the "bisecting" N-acetylglucosamine. These genetic, biochemical, and physiologic studies indicate conserved functions for N-glycan branches produced in the Golgi apparatus among two mammalian species and suggest possible therapeutic approaches to GlcNAcT-II deficiency. Our findings indicate that human genetic disease due to aberrant protein glycosylation can be modeled in the mouse to gain insights into N-glycan-dependent physiology and the pathogenesis of CDG-IIa.

Psychological adjustment and coping in a population of children with recurrent syncope.

The authors examined the association of psychological adjustment, styles of coping, and disease severity for children with recurrent syncope. Participants were 44 children and adolescents with a history of recurrent syncope and 40 healthy comparison control children. Dependent variables were measures of internalizing adjustment (e.g., anxiety, depression, withdrawal) reported by children and their parents and styles of coping reported by children. Parents reported higher frequencies of the internalizing of behavioral symptoms (i.e., anxiety, withdrawal) for children with recurrent syncope compared with their healthy counterparts. Children's self-reports did not reveal significant differences between the syncope and comparison groups in psychological adjustment and styles of coping. The authors conclude from these findings that adjustment difficulties, including symptoms of anxiety and social withdrawal, may occur with recurrent syncope. Implications for clinical practice and future research are discussed.

Promoting effective teaching and learning: hospital consultants identify their needs.

OBJECTIVES: The aim of this study was to help hospital consultants identify their needs in relation to teaching skills, leading to the development of a teacher training programme. DESIGN: The study was directed at all 869 consultants in the region and initially involved a postal questionnaire which had a 60.5% response rate. SETTING: Hospitals throughout Northern Ireland. SUBJECTS: Hospital consultants. RESULTS: Results from this questionnaire indicated that while the majority of respondents were interested teachers, only 34% had received any teacher training. The questionnaire was followed by a focus group study involving three groups of consultants drawn randomly from those who had responded to the questionnaire. Participants in these groups identified the following key areas of hospital education: qualities of hospital teachers; selection procedures; problems of teaching in hospitals; the need for teacher training and how it should be provided. CONCLUSION: The study highlighted that hospital teachers need to acquire and update their teaching skills through attending courses that should include basic teaching and assessment/appraisal skills. These courses should last 1 or 2 days and be provided at a regional or subregional level. As a result of this study, teacher training courses have been developed in this region.

Selective A1-adenosine receptor antagonists identified using yeast Saccharomyces cerevisiae functional assays.

Evaluation of a biased "library" of pyrrolo[2,3-d]pyrimidines using yeast-based functional assays expressing human A1- and A2a-adenosine receptors, led to the A1 selective antagonist 4b. A direct correlation between yeast functional activity and binding data was established. Practical compounds with polar residues at C-4 of the pyrrolopyrimidine system required H-bond donor functionality for high potency.

Experience with a low profile bipolar, active fixation pacing lead in pediatric patients.

Continued miniaturization of permanent pacing systems has promoted use of this technology in younger and smaller pediatric patients. Intermedics ThinLine 438-10 active fixation pacing leads (4.5 Fr lead body) were implanted in 26 patients (17 males/9 females; 9.9 +/- 6.9 years). Twenty of 26 patients received dual chamber systems, 6 of 26 patients single lead systems. Each patient has been followed 3 months. Pacemaker analysis at implant and 6 months later evaluated pulse width thresholds at 2.5 V (atrial 0.07 +/- 0.02 vs 0.13 +/- 0.02 ms [P = 0.01]; ventricular 0.08 +/- 0.04 ms vs 0.20 +/- 0.04 ms [P = 0.01]); sensing thresholds (atrial 4.1 +/- 0.41 mV vs 4.0 +/- 4.2 mV [P = NS]; ventricular 9.7 +/- 0.72 vs 9.3 +/- 0.94 mV [P = NS]); and impedance (atrial 345 +/- 12 vs 370 +/- 120 O [P = 0.04]; ventricular 412 +/- 17 vs 458 +/- 190 O [P < 0.01]). One volt lead failed with exit block at approximately 6 weeks. The youngest (9 months to 5 years) and smallest (6.5-18.0 kg) ten patients have each shown by venography to have at least mild venous stenosis at the lead(s) insertion site; five patients demonstrated collateral formation around asymptomatic obstruction, with no thrombus formation. The Intermedics 438-10 ThinLine pacing lead has demonstrated good and stable early postimplant electrical parameters. Angiographic evaluation in our smaller patients has shown evidence for asymptomatic venous obstruction.

Total cavopulmonary anastomosis (Fontan) in children with Down's syndrome.

BACKGROUND: There is a paucity of information to guide the management of the child with Down's syndrome and congenital heart disease in whom biventricular repair is precluded. METHODS: Through the cardiology and cardiovascular surgery databases of The Hospital for Sick Children and Toronto Congenital Cardiac Centre for Adults, we identified patients with trisomy 21 and ventricular hypoplasia who had undergone a Fontan procedure (or modification). RESULTS: Of 533 patients who had undergone a Fontan operation between 1976 and 1997, 4 had trisomy 21. All 4 patients had unbalanced complete atrioventricular septal defect with right ventricular hypoplasia in 3 and left ventricular hypoplasia in 1. Three patients survived, and 1 died of endocarditis. The 3 survivors have done well in the short term and medium term without complications related to the pulmonary vasculature. CONCLUSIONS: We suggest that in appropriately selected patients with trisomy 21 and ventricular hypoplasia who are unsuitable for two or one and a half ventricle repair, the Fontan procedure is not contraindicated and provides short-term and medium-term benefit.

Pegylated peptides. V. Carboxy-terminal PEGylated analogs of growth hormone-releasing factor (GRF) display enhanced duration of biological activity in vivo.

In the present study, human growth hormone-releasing factor (hGRF) and analogs were successfully pegylated at the carboxy-terminus using a novel solid- and solution-phase strategy. Following synthesis, these pegylated hGRF analogs were evaluated for in vitro and in vivo biological activity. Specifically, hGRF (1-29)-NH2, [Ala15]-hGRF (1-29)-NH2, [desNH2Tyr1, D-Ala2, Ala15]-hGRF(1-29)-NH2 and [His1, Val2, Gln8, Ala15, Leu27]-hGRF(1-32)-OH were each C-terminally extended using a Gly-Gly-Cys-NH2 spacer (previously demonstrated not to alter intrinsic biological activity), and then monopegylated via coupling to an activated dithiopyridyl-PEG reagent. PEG moieties of 750, 2000, 5000 or 10,000 molecular weight (MW) were examined to determine the effect of polymer weight on activity. Initial biological evaluations in vitro revealed that all C-terminally pegylated hGRF analogs retained high growth hormone (GH)-releasing potencies, regardless of the MW of PEG polymer employed. Two of these pegylated hGRF analogs, [desNH2Tyr1, D-Ala2, Ala15]-hGRF (1-29)-Gly-Gly-Cys(NH2)-S-Nle-PEG5000 and [His1, Val2, Gln8, Ala15, Leu27]-hGRF(1-32)-Gly-Cys(NH2)-S-Nle-PEG5000, were subsequently evaluated in both pig and mouse models and found to be highly potent (in vivo potency range = 12-55-fold that of native hGRF). Relative to their non-pegylated counterparts, these two pegylated hGRF analogs exhibited enhanced duration of activity.

Transhepatic access to the atrioventricular ring for delivery of radiofrequency energy.

INTRODUCTION: Transcatheter radiofrequency ablation is an effective, safe treatment of arrhythmias in children. However, despite technical advances, patients with obstructed venous access to the heart have not been candidates for this treatment. METHODS AND RESULTS: Two children (8.2 and 10.9 kg) with complex congenital heart disease, supraventricular tachycardia, and obstructed venous access underwent successful radiofrequency ablation of either a right (one patient) or left (one patient) accessory pathway using the transhepatic route to the heart. CONCLUSION: This experience underscores the usefulness of the transhepatic approach in small patients, in patients with limited venous access, and in patients with complex congenital heart disease.

Additive impact of in-hospital cardiac arrest on the functioning of children with heart disease.

OBJECTIVE: This study examined the impact of a sudden cardiac arrest (CA) on the neurodevelopmental and adaptive functioning of young children with congenital heart disease (CHD). METHODOLOGY: Sixteen children with CHD who had sustained an in-hospital CA were compared with a medically similar group of children with CHD who had not incurred a CA. The contribution of CA, disease severity, and family socioeconomic status on the prediction of developmental outcome variables was evaluated. RESULTS: Children in the CA group displayed more impairments in general cognitive, motor, and adaptive behavior functioning as well as greater disease severity as measured by a cumulative medical risk index. With respect to all children in the study, a higher socioeconomic status was related to higher scores on cognitive functioning, lower levels of child maladjustment, and lower levels of stress within the parent-child relationship. Although the occurrence of a CA alone did not contribute to the prediction of outcome measures, a significant interactional effect between CA and cumulative medical risk index was found. Specifically, among children who had incurred a CA, as disease severity increased, decrements in abilities were observed. Few significant correlations between specific CA-related variables (eg, length of CA) and outcome indices were found. CONCLUSIONS: Results from this study indicate that the impact of cardiac arrest on neuropsychological functioning may be mediated by the child's overall disease severity. These findings have implications for the identification of CA survivors at greatest risk for developmental difficulties.

Effects of dual-chamber pacing for pediatric patients with hypertrophic obstructive cardiomyopathy.

OBJECTIVES: The effects of both temporary and permanent dual-chamber pacing (DCP) were evaluated in symptomatic pediatric patients with hypertrophic obstructive cardiomyopathy (HOCM) unresponsive to medications. BACKGROUND: Permanent DCP pacing can reduce left ventricular outflow tract (LVOT) gradient and relieve symptoms in adult patients with HOCM. METHODS: Ten patients (mean [+/-SD] age 11.1 +/- 6 years, range 1 to 17.5) with HOCM and a Doppler LVOT gradient > or = 40 mm Hg were studied. The seven patients showing hemodynamic improvement during temporary pacing at cardiac catheterization underwent surgical implantation of a permanent DCP system. The effects of permanent pacing were evaluated using a questionnaire, Doppler evaluation, treadmill testing and repeat cardiac catheterization. RESULTS: At initial cardiac catheterization, three patients failed to respond to temporary pacing (inadequate pace capture in two; congenital mitral valve abnormality in one). The remaining seven patients (70%, 95% confidence interval 38.0% to 91.7%, mean age 13 +/- years, range 4 to 17.5) showed a significant reduction (p < 0.05) in LVOT gradient, left ventricular systolic pressure and pulmonary capillary wedge pressure. After pacemaker implantation, these seven patients reported a significant reduction in dyspnea on exertion and exercise intolerance. Serial Doppler evaluation showed a significant reduction in LVOT gradient. Follow-up catheterization at 23 +/- 4 months in six patients (one patient declined restudy) showed a persistent decrease in LVOT gradient (53 +/- 13 vs. 16 +/- 11 mm Hg), left ventricular systolic pressure (149 +/- 16 vs. 108 +/- 14 mm Hg) and pulmonary capillary wedge pressure (18 +/- 2 vs. 12 +/- 4 mm Hg) versus preimplantation values. CONCLUSIONS: Permanent DCP is an effective therapy for selected pediatric patients with HOCM. Rapid atrial rates and intrinsic atrioventricular conduction, as well as congenital mitral valve abnormalities, may preclude effective pacing in certain patients.