Angiotensin I converting enzyme genotype affects ventricular remodelling in children with aortic coarctation.
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Aortic Coarctation↗
Biomedical subjects
J L Wilkinson
Publications and source records attributed to J L Wilkinson.
Nicotine serves as a feature-positive modulator of Pavlovian appetitive conditioning in rats.
The present experiments examined whether a nicotine state could set the occasion for a pairing between visual cues and a rewarding outcome in rats. Following nicotine administration, presentation of a conditional stimulus (CS; light-on) was followed by brief access to a sucrose solution. When saline was administered, the same CS was presented but was not followed by any consequence. In Experiment 1, two groups assessed whether rats could acquire this Pavlovian feature-positive discrimination via different training procedures. An anticipatory food-seeking conditioned response (CR) developed during the CS on nicotine sessions but not on saline sessions in both groups. In Experiment 2, centrally acting antagonists of nicotinic acetylcholine and opiate receptors (mecamylamine and naloxone, respectively) dose-dependently blocked nicotine's control of the CR, whereas the peripherally acting nicotinic antagonist hexamethonium had no effect. Increasing or decreasing the interval between nicotine administration and testing also attenuated the CR. These results are consistent with the hypothesis that nicotine can occasion appetitive Pavlovian relations via its action at central nervous system cholinergic receptors.
Animals↗
Long term somatic growth after repair of tetralogy of Fallot: evidence for restoration of genetic growth potential.
OBJECTIVE: To compare actual with predicted long term growth after early repair of tetralogy of Fallot (TOF). DESIGN: Serial preoperative and postoperative anthropometric data were converted with z scores. The presence of restrictive physiology was assessed by echocardiography. PATIENTS: 45 otherwise healthy patients who underwent repair at median age 1.6 years (range 0.2-4.9) were studied. Predicted height was determined from mid-parental height corrected for sex. RESULTS: Mean (SD) weight and height z scores at the time of surgery were significantly depressed (-1.04 (0.82) and -0.93 (0.95), respectively; p < 0.0001 for both). At latest follow up at a median age of 14.2 years (range 11-20.5), mean weight and height z scores were 0.16 (1.1) and -0.05 (0.81) (p = 0.32 and p = 0.41, respectively). The improvement between surgical and late weight and height z scores was significant (p < 0.0001 for each comparison). Catch up growth was largely complete within two years. Age at correction, duration of follow up, and prior surgical procedures were unrelated to growth. Mean current height z scores were similar to those predicted by mid-parental height. Patients with restrictive right ventricular physiology (n = 24) had a significantly greater late z score for weight (0.49 v -0.34; p = 0.01), with a similar trend for height. Low birth weight patients experienced comparable catch up growth but remained shorter than patients with normal birth weight (mean height z score -0.64 v 0.06; p = 0.03). CONCLUSIONS: Early repair of TOF results in significant acceleration of weight and height, with normalisation of long term growth and fulfilment of genetic growth potential.
Adolescent↗
Prospective comparison of costs and short term health outcomes of surgical versus device closure of atrial septal defect in children.
OBJECTIVE: To compare surgical and device closure of isolated secundum atrial septal defect (ASD) in terms of hospital costs, clinical outcome, and impact on the patient and family. DESIGN: Prospective, observational study. SETTING: Paediatric tertiary referral centre. PATIENTS: Consecutive local children with a secundum ASD, admitted between 1 May 1999 and 1 May 2001. METHODS: Parents completed a standardised questionnaire at recruitment (on admission), at discharge, and one month after the procedure. Clinical and hospital generated cost data were collated at discharge. RESULTS: 62 children were included in the analysis: 19 who underwent surgical repair and 43 who underwent device closure with the Amplatzer septal occluder. Median procedure times and hospital stay were significantly longer for surgical patients (170 (147 to 180) v 92 (70 to 115) minutes and 88 (78 to 112) v 29 (28 to 30) hours, respectively; p < 0.01). There was no difference in the complication rate. No device patients required intensive care or blood products. The median values for postoperative pain score, analgesia use, and convalescence time were greater for surgical patients. The median cost of each procedure was similar, but higher nursing and laboratory costs contributed to a slightly greater total cost for surgical repair (Aus$12 969 ($11 569 to $14 215) v Aus$11 845 ($10 669 to $12 555), p = 0.03). CONCLUSIONS: Device closure of ASD involves a shorter hospital stay, causes less discomfort and familial disturbance, and carries less cost than surgical closure. However, there should be guarded acceptance of this technique until long term data are available.
Adolescent↗
Clinical, electrocardiographic, and histologic correlations in children with dilated cardiomyopathy.
OBJECTIVE: To determine whether presenting electrocardiography is related to histologic findings and clinical outcomes in children with dilated cardiomyopathy. BACKGROUND: Lymphocytic myocarditis is an important cause of childhood dilated cardiomyopathy, the outcome of which is unclear. The results of non-invasive investigations are often used to infer the presence or absence of lymphocytic myocarditis. METHODS: Thirty-four children, presenting acutely with dilated cardiomyopathy, underwent both early electrocardiography and endomyocardial biopsy. The parameters examined included heart rate, PR, QRS, and corrected QT intervals, R-wave voltages in Leads V(1) and V(6), S-wave voltages in Leads V(1) and V(6), and sum of SV(1) and RV(6). We expressed measurements as Z scores, based on published normal values for age and gender. RESULTS: A total of 15 patients had lymphocytic myocarditis on endomyocardial biopsy (Group I), and 19 had non-specific histologic findings (Group II). We did not distinguish the 2 groups by age, time to endomyocardial biopsy, or duration of follow-up. Group I patients had significantly smaller R-wave Z scores in Leads V(1) and V(6), and combined S in V(1) and R in V(6) Z scores (p < 0.02 for each). The positive and negative predictive values of an R-wave amplitude in V(6) < 5th percentile were 75% and 65%, respectively, for the diagnosis of lymphocytic myocarditis. An R-wave amplitude in V(6) > 95th percentile had a positive and negative predictive value of 80% and 63%, respectively, for the diagnosis of idiopathic dilated cardiomyopathy. Survival and freedom from late cardiac dysfunction were more common among Group I patients compared with Group II (p <or= 0.02 for both). CONCLUSION: Myocardial histology cannot reliably be inferred from the presenting electrocardiogram. Survival and outcome for children with lymphocytic myocarditis is better than for those with non-specific histology.
Biopsy↗
Successful occlusion of a coronary arteriovenous fistula using an Amplatzer duct occluder.
In an 11-year old boy with a large coronary arteriovenous fistula between the left coronary artery and the right atrium, we achieved successful closure using a 10-8 Amplatzer Duct Occluder introduced from the right internal jugular vein. Angiography 6 weeks later showed complete occlusion of the fistula, with normal opacification of the left coronary arterial system. This technique may be used as an alternative to coils and surgery in selected patients.
Arteriovenous Fistula↗
T wave alternans threshold in normal children.
INTRODUCTION: Sustained microvolt-level T wave alternans (TWA) during exercise is a predictor of ventricular arrhythmia propensity in adult populations. TWA occurs in normal adults, but it is rare at < 70% of predicted maximum heart rate. An onset heart rate < or = 110 is believed to be significant. The aim of this study was to examine the feasibility of performing the test in children and to determine the normal heart rate threshold for sustained TWA in children. METHODS AND RESULTS: Alternans was evaluated during bicycle exercise in 100 normal volunteers aged 8 to 17 years. Adequate resting data were obtained in 76 of 100 children and was negative in all. Exercise data from 16 of 100 was excluded due to excessive noise. Median maximum heart rate was 192 (range 140 to 214). Sustained alternans was absent in 75 (89%) of 84. In the nine children with sustained alternans, median onset heart rate was 138 (range 120 to 158), and 7 of 9 had an onset heart rate > or = 135. Median heart rate threshold as a percentage of predicted maximum heart rate (220 - age) was 67% (range 58% to 76%). Only 1 subject (1.2%) had an onset heart rate < 60% of predicted maximum. There was no significant difference between age, gender, endurance, maximum heart rate, QRS duration, QT interval, or QTc in those with and those without sustained TWA. CONCLUSION: Noninvasive assessment of TWA is feasible at > or = 8 years of age. Sustained TWA was present in 11% of normal children, but was absent at heart rates below 120 and rare (1.2%) below 60% of predicted maximum heart rate.
Adolescent↗
Haemodynamic calculations in the catheter laboratory.
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Cardiac Catheterization↗
New interventional therapeutic approach for dual drainage of the scimitar vein.
A patient with scimitar syndrome and dual drainage of a right-sided scimitar vein into the inferior vena cava and the left atrium underwent coil occlusion of the right aortopulmonary collateral artery and device occlusion of the lower scimitar vein drainage, leaving it flowing solely into the left atrium.
Child, Preschool↗
Interventional pediatric cardiology: device closures.
Surgical treatment of various septal defects has been long established. With the advances in transcatheter therapy dilatation techniques for valvular stenosis and vascular obstruction have become established procedures. Closure of septal defects in the catheterization laboratory has also been introduced; some of these have come into regular use in current practice. In 1967, Porstmann et al reported the use of Ivalon plug to close patent ductus arteriosus (PDA). Since then, several devices have been used including Rashkind PDA ocluder (not being used now), Gianturco coils, detachable coils (for small PDA), CardioSEAL and other umbrella devices and Amplatzer PDA occluder. Closure rates vary from 95-98% in most series, however, some of these devices are very expensive, more so, when compared to the cost of surgical ligation of PDA. Catheter closure of secundum atrial septal defect (ASD) has also been done by various devices like clamshell device, Sideris Buttoned device, ASDOS device, Amplatzer device and cardioSEAL. So far no device has been accepted as ideal for every case, however, Amplatzer device has been used most extensively. Issues such as completeness of endothelialisation, incidence of late arrhythmias, endocarditis remain uncertain. However, in select population of ASD cases with a central secundum defect, device closure is being used increasingly. Device closure of ventricular septal defect remains challenging and controversial and is probably available to a small group of children with defects that are difficult to close surgically and involve higher risk.
Cardiac Catheterization↗
Congenital Heart Surgery Nomenclature and Database Project: corrected (discordant) transposition of the great arteries (and related malformations).
The extant nomenclature for congenitally corrected transposition of the great arteries is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. Congenitally corrected transposition of the great arteries is a complex cardiac lesion that is associated with ventricular septal defect, left ventricular outflow tract obstruction, and tricuspid valve abnormalities. Nomenclature for this lesion has been variable and confusing. Herein we attempt to clarify the terminology, with an emphasis on identification of synonymous and nonsynonymous appellations. A comprehensive database set is presented that is based on a hierarchical scheme. Data are entered at various levels of complexity and detail that can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented that will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.
Databases, Factual↗
Pulmonary vascular resistance and reactivity in children with end-stage cardiomyopathy.
Pulmonary vascular resistance (PVR) and reactivity were compared in 63 children with end-stage cardiomyopathy (CM) referred for cardiac transplantation. Diagnostic category of CM was the sole determinant of PVR. Compared with other patients, children with restrictive CM were younger at diagnosis and had a significantly higher pulmonary vascular resistance index (PVRI). Children with a baseline PVRI of up to 11.8 units per meter squared (U.m(2)) who showed reactivity underwent successful orthotopic cardiac transplantation.
Adolescent↗
The diagnosis of innocent murmurs in childhood.
Innocent murmurs are common in childhood. They require accurate diagnosis to avoid unnecessary anxiety and/or restrictions. With this in mind, we studied prospectively children diagnosed by a paediatric cardiologist as having innocent murmurs to review the necessity of investigations in excluding organic abnormalities. We included 63 children in the study. The majority had the so-called Still's, or musical/vibratory murmur. None had abnormal investigations, suggesting that such investigations are largely superfluous for the purpose of diagnosis in those patients with innocent murmurs seen by a paediatric cardiologist. They are often done, nonetheless, as part of the assessment and/or expectations of the parent or the referring physician.
Auscultation↗
Interventional pediatric cardiology: device closures.
Surgical treatment of various septal defects has been long established. With the advances in transcatheter therapy dilatation techniques for valular stenosis and vascular obstruction have become established procedures. Closure of septal defects in the catheterization laboratory has also been introduced; some of these have come into regular use in current practice. In 1967, Porstmann et al reported the use of Ivalon plug to close patent ductus arteriosus (PDA). Since then, several devices have been used including Rashkind PDA occluder (not being used now), Gianturco coils, detachable coils (for small PDA), CardioSEAL and other umbrella devices and Amplatzer PDA occluder. Closure rates vary from 95-98% in most series, however, some of these devices are very expensive, more so, when compared to the cost of surgical ligation of PDA. Catheter closure of secundum atrial septal defect (ASD) has also been done by various devices like clamshell device, Sideris Buttoned device, ASDOS device, Amplatzer device and cardioSEAL. So far no device has been accepted as ideal for every case, however, Amplatzer device has been used most extensively. Issues such as completeness of endothelialisation, incidence of late arrhythmias, endocarditis remain uncertain. However, in a select population of ASD cases with a central secundum defect, device closure is being used increasingly. Device closure of ventricular septal defect remains challenging and controversial and is probably available to a small group of children with defects that are difficult to close surgically and involve higher risk.
Cardiovascular Surgical Procedures↗
Can transcatheter closure of atrial septal defect be regarded as a 'standard' procedure?
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Cardiac Catheterization↗
Infective endocarditis on an occluder closing an atrial septal defect.
Closure of atrial septal defects be means of intravenous catheterisation has been undertaken using a variety of devices as an alternative to surgical closure. We describe the first case, to the best of our knowledge, of infective endocarditis complicating a successful transcatheter closure. This highlights the potential risk of this procedure, and emphasises the need for appropriate antibiotic prophylaxis until complete endothelialization of the device has occurred.
Anti-Bacterial Agents↗
Arterial switch in hearts with left ventricular outflow and pulmonary valve abnormalities.
BACKGROUND: Pulmonary valve and left ventricular outflow tract abnormalities (LVOT) may not be absolute contraindications to arterial switch operation (ASO). METHODS: In this study we analyze long-term outcome for 26 such transposition patients (6.3% of our ASO cohort). Median age and weight were 69 days (7 to 3,631 days) and 4.5 kg (2.6 to 34 kg). Pulmonary valve abnormalities included bicuspid valve (n = 4) and dysplastic valve (n = 5). The LVOT abnormalities (n = 17) included accessory atrioventricular valve/endocardial cushion tissue, fibromuscular ring, anomalous muscle bands, and septal malalignment. Patients with dynamic LVOT obstruction were excluded. The median preoperative left ventricular to pulmonary artery peak systolic pressure gradient was 30 mm (0 to 93 mm), or 50 mm (16 to 93 mm) if patients with isolated valve abnormalities are excluded. The ASO was performed according to our standard technique with or without LVOT resection or pulmonary valvotomy as required. RESULTS: There were two perioperative deaths (7.7%; 95% confidence interval, 0.9% to 25%), and no late deaths during 1,934 patient-months of follow-up time. Actuarial freedom from reoperation for neoaortic valve or LVOT problems is 87% (+/- 7) at 130 months, representing two reoperations. One was performed for neoaortic insufficiency plus LVOT obstruction, and the other for isolated LVOT obstruction. One patient currently has significant neoaortic insufficiency, and median gradient at last follow-up is 0 mm Hg (range, 0 to 35 mm Hg). CONCLUSIONS: The ASO can be performed in selected patients with transposition of the great arteries and with LVOT abnormalities with early and late survival and functional status similar to that of matched patients with normal pulmonary valves and LVOT (p > 0.05), but with a greater hazard for reoperation (p < 0.05). Selection for ASO should be based on anatomic criteria rather than left ventricular to pulmonary artery gradient alone, to avoid assigning these patients with transposition of the great arteries to treatment strategies less satisfactory than ASO.
Child↗
Early clinical experience with use of the 'Amplatzer Septal Occluder' device for atrial septal defect.
Device closure of oval fossa atrial septal defects with the Amplatzer Septal Occluder was performed in 26 patients ranging in age from 0.89 to 60.44 years. In eight additional patients no device implant was performed because of the presence of multiple defects or because the defect was of a size unsuitable for closure with the devices currently available. The stretched diameter of the defects that were closed ranged from 4 to 23 mm (mean 14+/-5.4 mm) and device sizes ranged from 4 to 24 mm. Two devices were unstable, of which one embolized to the right atrium after release. Both devices were retrieved at the same procedure. One of these patients subsequently underwent a successful device closure of his defect using a larger (24-mm) device. Three patients had multiple defects, which were successfully closed with a single device. At 1-month follow-up 23/26 (88%) and at 3-month follow-up 22/24 (92%) patients had complete closure of their defects, while two had residual shunts. One further patient who had complete closure of his defect at 1-month post-implant had his device removed and his atrial septal defect patched surgically 8 weeks after device closure. This was done as a result of the development of a vegetation affecting the device after an episode of septicaemia, which was not related to the cardiac problems. There was no procedure-related morbidity or mortality and all patients remain well at the present time.
Adolescent↗