Deriving fontan-specific normative exercise data from well-functioning adolescents.

Background: Exercise capacity is reduced in patients with a Fontan circulation compared to their healthy peers secondary to altered haemodynamics of the Fontan circulation. Cardiopulmonary exercise testing is routinely used in Fontan patients to assess their cardiopulmonary response to exercise and help guide management decisions, however their results are routinely compared to normative data derived from healthy individuals.

Method: Using data available from the Pediatric Heart Network, we performed a retrospective study to derive Fontan-specific normative values in a subgroup of well-functioning adolescent patients.

Peak Oxygen Consumption Scaled to Body Composition Is Associated With Mortality and Morbidity in People With a Fontan Circulation.

Background: Peak oxygen consumption (peak O) is traditionally scaled by body mass, but it is most appropriately scaled by fat-free mass. However, it is unknown whether peak O scaled by fat-free mass is associated with mortality and morbidity in people with a Fontan circulation. The aim of this study was to assess the associations between different expressions of peak O with mortality and morbidity in people with a Fontan circulation.

Percentage Predicted Peak Oxygen Consumption in People With Fontan Circulation: A Rapid Systematic Scoping Review and Validation Study.

Background: Peak oxygen consumption (peak ) is routinely measured in people who have congenital heart disease and is reported as a percentage of predicted value, based upon age- and sex-matched normative reference values (NRVs). This study aimed to identify which NRVs are being used, assess whether NRVs are being applied appropriately, and evaluate if recommended NRVs are valid when applied to people with congenital heart disease.

Methods And Results: A systematic scoping review identified studies that reported peak percentage of predicted value in people with congenital heart disease.

O2 pulse slope correlates with stroke volume during exercise in patients with a Fontan circulation.

Background: Peak oxygen pulse (Opulse=oxygen consumption/heart rate) is calculated by the product of stroke volume (SV) and oxygen extraction. It has been shown to be reduced in patients with a Fontan circulation. However, in the Fontan population, it may be a poor marker of SV.

Scaling Peak Oxygen Consumption for Body Size and Composition in People With a Fontan Circulation.

Background Peak oxygen consumption (peak ) is traditionally divided ("ratio-scaled") by body mass (BM) for clinical interpretation. Yet, it is unknown whether ratio-scaling to BM can produce a valid size-independent expression of peak in people with a Fontan circulation. Furthermore, people with a Fontan circulation have deficits in lean mass, and it is unexplored whether using different measures of body composition may improve scaling validity.

Older age at Fontan completion is associated with reduced lung volumes and increased lung reactance.

Background: Fontan patients have abnormal lung function, in particular restrictive lung disease and low diffusing capacity of carbon monoxide (DLCO). We sought to further characterise these abnormalities with detailed pulmonary function testing and examine associations with clinical parameters.

Methods: 132 Fontan patients across Australia and New Zealand underwent spirometry, with 126 subjects included in final analyses.

Impairments in Pulmonary Function in Fontan Patients: Their Causes and Consequences.

Patients with a Fontan circulation lack a sub-pulmonary ventricle with pulmonary blood flow passively redirected to the lungs. In the Fontan circulation, ventilation has a significant influence on pulmonary blood flow and cardiac output both at rest and with exercise. Children and adults with a Fontan circulation have abnormalities in lung function.

The Degree of Left Ventricular Hypoplasia Is Associated with Tricuspid Regurgitation Severity in Infants with Hypoplastic Left Heart Syndrome.

Tricuspid valve regurgitation (TR) increases adverse outcomes in children with hypoplastic left heart syndrome (HLHS). Changes in tricuspid valve (TV) annulus and leaflet geometry have been described but the underlying causes for TR in HLHS remain uncertain. We aimed to examine the association between left ventricular (LV) size and TR in infants with HLHS as right ventricular (RV)-LV interactions may be important in TR development.

Inspiratory Muscle Training Is Associated With Improved Inspiratory Muscle Strength, Resting Cardiac Output, and the Ventilatory Efficiency of Exercise in Patients With a Fontan Circulation.

Background: Patients with a Fontan circulation have reduced exercise capacity and respiratory muscle strength. Inspiratory muscle training (IMT) improves exercise capacity and quality of life in adults with heart failure. We assessed whether 6 weeks of a home-based program of IMT improves inspiratory muscle strength and the ventilatory efficiency of exercise in adolescent patients with a Fontan circulation.

Isolated Anomalous Origin of Left Pulmonary Artery From the Descending Aorta: An Embryologic Ambiguity.

Anomalous origin of a branch pulmonary artery from the aorta is a rare malformation, accounting for 0.12% of all congenital heart defects. Anomalous origin of the left pulmonary artery from the aorta (ALPA) constitutes a small proportion of these cases.

The role of bacterial and non-bacterial toxins in the induction of changes in membrane transport: implications for diarrhea.

Bacterial toxins induce changes in membrane transport which underlie the loss of electrolyte homeostasis associated with diarrhea. Bacterial- and their secreted toxin-types which have been linked with diarrhea include: (a) Vibrio cholerae (cholera toxin, E1 Tor hemolysin and accessory cholera enterotoxin); (b) Escherichia coli (heat stable enterotoxin, heat-labile enterotoxin and colicins); (c) Shigella dysenteriae (shiga-toxin); (d) Clostridium perfringens (C. perfringens enterotoxin, alpha-toxin, beta-toxin and theta-toxin); (e) Clostridium difficile (toxins A and B); (f) Staphylococcus aureus (alpha-haemolysin); (g) Bacillus cereus (cytotoxin K and haemolysin BL); and (h) Aeromonas hydrophila (aerolysin, heat labile cytotoxins and heat stable cytotoxins).

Quinacrine blocks PrP (106-126)-formed channels.

We investigated the action of the acridine derivative, quinacrine (QC), which has been shown to act as a noncompetitive channel inhibitor. The main effects of QC are voltage- and concentration-dependent changes in the kinetics of the prion protein fragment (PrP[106-126])-formed cation channels. The current-voltage relationships show that the maximal current (I) was not affected whereas the physiologically important mean current (I') was reduced as a result of changes in channel kinetics.

Heterogeneous amyloid-formed ion channels as a common cytotoxic mechanism: implications for therapeutic strategies against amyloidosis.

The amyloidoses consist of human and animal chronic, progressive, and sometimes fatal diseases that are characterized by the deposition of insoluble proteinaceous amyloid fibrils in various tissues. Despite the biochemical diversity of amyloids, they share certain properties. The amphipathic and the charged nature of many amyloid-forming peptides point to their intrinsic ability to form diverse beta-sheet-based aggregates and channel types in negatively charged membranes.