Normally and abnormally functioning left-sided porcine bioprosthetic valves after long-term implantation in patients: Distinct spectra of histologic and histochemical changes

This morphologic study (X-ray examination of gross specimens, histologic study and histochemical staining) compares two groups of explanted left-sided biopros-thetic valves: group 1,6 valves with normal cusp function and group II, 10 valves with significant dysfunction. Implantation periods ranged from 26 to 79 months. A computerized descriptive statistical method (principal component analysis) is used to analyze the qualitative results. Although qualitatively identical alterations are observed in both groups, the findings in the deep layers of the cusps of severe collagen breakdown, intensive fibrin penetration and various degrees of calcification are restricted to group II. Other findings of interest in both groups include amyloid deposits (four cases) and layering of fusiform host cells on the cusp surface (three cases).The computerized study shows that individuals of one clinical group are morphologically different from those of the other. Mechanical stress may contribute to surface alterations early after implantation, while further collagen breakdown and macrophagic activity result in deep penetration of plasma components and fibrin. Subsequent calcification is likely to be dystrophic rather than metabolic. Colonization of the cuspal surface by endothelial cells after long-term implantation of bioprosthetic valves expresses a new type of relation between host and bioprosthesis

Virtuality in human supervisory control: Assessing the effects of psychological and social remoteness

Virtuality would seem to offer certain advantages for human supervisory control. First, it could provide a physical analogue of the 'real world' environment. Second, it does not require control room engineers to be in the same place as each other. In order to investigate these issues, a low-fidelity simulation of an energy distribution network was developed. The main aims of the research were to assess some of the psychological concerns associated with virtual environments. First, it may result in the social isolation of the people, and it may have dramatic effects upon the nature of the work. Second, a direct physical correspondence with the 'real world' may not best support human supervisory control activities. Experimental teams were asked to control an energy distribution network. Measures of team performance, group identity and core job characteristics were taken. In general terms, the results showed that teams working in the same location performed better than team who were remote from one another

Drug-Induced Brugada Syndrome in Children Clinical Features, Device-Based Management, and Long-Term Follow-Up

ObjectivesThe goal of this study was to investigate the clinical features, management, and long-term follow-up of children with drug-induced Brugada syndrome (BS).BackgroundPatients with BS <12 years of age with a spontaneous type I electrocardiogram have a higher risk of arrhythmic events. Data on drug-induced BS in patients <12 years of age are lacking.MethodsAmong 505 patients with ajmaline-induced BS, subjects ≤12 years of age at the time of diagnosis were considered as children and eligible for this study.ResultsForty children (60% male; age 8 ± 2.8 years) were included. Twenty-four children (60%) had a family history of sudden death. Two (5%) had a previous episode of aborted sudden death, and 8 (20%) had syncope. Children experienced more frequent episodes of sinus node dysfunction (SND) compared with older subjects (7.5% vs. 1.5%; p = 0.04) and had a comparable incidence of atrial tachyarrhythmias. Children more frequently experienced episodes of ajmaline-induced sustained ventricular arrhythmias (VAs) compared with older patients (10.0% vs. 1.3%; p = 0.005). Twelve children (30%) received an implantable cardioverter-defibrillator (ICD). After a mean follow-up time of 83 ± 51 months, none of the children died suddenly. Spontaneous sustained VAs were documented in 1 child (2%). Among children with ICD, 1 (8%) experienced an appropriate shock, 4 (33%) had inappropriate ICD shocks, and 4 (33%) experienced device-related complications.ConclusionsDrug-induced BS is associated with atrial arrhythmias and SND. Children are at higher risk of ajmaline-induced VAs. The rate of device-related complications, leading to lead replacement or inappropriate shocks, is considerable and even higher than with appropriate interventions. Based on these findings, the optimal management of BS in childhood should remain individualized, taking into consideration the patient's clinical history and family's wishes

Heart-lung transplantation for terminal pulmonary lymphangioleiomyomatosis

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

Genua vara, genua valga, medical and lateral Blount's disease. A frequent orthopaedic disorder in the Netherlands Antilles

This retrospective study concerns 112 children in the Netherlands Antilles with genua vara, genua valga, medial and lateral Blount's disease of the infantile type. Suggestive causal factors have been studied. Early orthopaedic treatment or osteotomy results in complete relief and prevents evolution to a severe deformity. The stage IV deformity can be improved by surgical means (multiple osteotomies), but complete correction cannot be obtained.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Surgical treatment of Wolff-Parkinson-White syndrome: A timeless procedure?

Catheter-induced radiofrequency (RF) ablation has become the initial non-pharmacological treatment option for Wolff-Parkinson-White (WPW) syndrome. In this report, we present the successful surgical treatment of WPW syndrome in two patients in whom percutaneous ablation of the accessory pathway was not successful

Early clinical experience with the bi-leaflet St. Jude medical cardiac valve prosthesis

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

Combined heart-lung transplantation for terminal pulmonary lymphangioleiomyomatosis

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Myocardial protection with combined selective profound hypothermia and hyperkaliemic cardioplegic arrest in aortic valve replacement

To analyse the results of combined profound myocardial hypothermia and cardioplegic hyperkalemic arrest for aortic valve replacement a series of 100 consecutive patients undergoing isolated or combined aortic valve replacement was reviewed. There was no operative or early postoperative mortality, only one patient presented with low cardiac output syndrome. Inotropic support was used in 8, vasodilator therapy in 4 and external pacing in 8 instances. Reoperation for bleeding occurred twice. Postpericardiotomy syndrome was present in 7 patients; requiring surgical drainage in 2. Conduction defects (>48 H) were present in 3 and supraventricular arrhythmias in 15 patients successfully treated with medical therapy in 5 and D.C. countershock in 10. The clinical results confirm that this simple myocardial protection technique provides an excellent myocardial preservation for all patients operated for single or combined aortic valve replacement.SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe