Large spin Hall angle in vanadium film.

We report a large spin Hall angle observed in vanadium films sputter-grown at room temperature, which have small grain size and consist of a mixture of body centered tetragonal (bct) and body centered cubic (bcc) structures. The spin Hall angle is as large as θ V = -0.071 ± 0.003, comparable to that of platinum, θ Pt = 0.076 ± 0.007, and is much larger than that of bcc V film grown at 400 °C, θ V_bcc = -0.012 ± 0.002. Similar to ß-tantalum and ß-tungsten, the sputter-grown V films also have a high resistivity of more than 200 µΩ∙cm. Surprisingly, the spin diffusion length is still long at 16.3 nm. This finding not only indicates that specific crystalline structure can lead to a large spin Hall effect but also suggests 3d light metals should not be ruled out in the search for materials with large spin Hall angle.

Cardiopulmonary exercise performance in adult survivors of the Mustard procedure.

Most patients with the Mustard procedure are now adults. To date, however, there have been few reports on resting and exercise hemodynamics in a large population of adults with this circulation. The aim of this study is to describe such parameters in one of the largest and oldest populations of adults with the Mustard procedure. The database of the University of Toronto Congenital Cardiac Centre for Adults was examined to identify 84 adults with the Mustard procedure who have undergone cardiopulmonary exercise tests. Magnetic resonance imaging and echocardiography studies were obtained in order to assess right ventricular size, function and baseline hemodynamics. Patients achieved lower maximum uptake of oxygen, maximal heart rate, forced vital capacity, forced expiratory volume in 1 second, and oxygen saturations at maximal exercise compared to a healthy population. Magnetic resonance imaging showed significantly different right ventricular ejection fractions between patients and controls. There were no effects of operative variables or preoperative hemodynamics on current exercise capacity. Patients after the Mustard procedure have subnormal exercise capacities. Factors such as chronotropic incompetence, peripheral deconditioning, and impaired lung function may be responsible for these results.

Lung function and aerobic capacity in adult patients following modified Fontan procedure.

OBJECTIVE: To examine cardiopulmonary performance in 52 adult patients with a Fontan circulation. DESIGN: Retrospective cohort study. Values of maximum oxygen uptake (VO(2)max), maximum heart rate (HRmax), forced vital capacity (FVC), and forced expiratory volume in one second (FEV(1)) were compared with predictive values for different age groups. Patients were further subdivided into those with a pulmonary artery connection (RA-PA) or right atrium to right ventricle conduit (RA-RV). RESULTS: At late follow up (median 10 years, range 1 to 26 years), patients with Fontan circulation had greatly diminished VO(2)max, HRmax, FVC, and FEV(1) compared with predicted values. Early age at surgery had a positive impact on aerobic capacity. The FEV(1):FVC ratio indicated restrictive lung function. No differences were found with respect to any variable between patients with RA-PA connections and those with RA-RV connections. CONCLUSIONS: Patients with a Fontan circulation have greatly diminished values of aerobic capacity and a restrictive pattern of lung function. Patients with an early surgical procedure obtained higher values of VO(2)max. The theoretical benefits of including the right ventricle in a Fontan circulation were not apparent.

Aerobic capacity in adults with various congenital heart diseases.

As an increasing number of patients with congenital heart disease reach adulthood, more information is needed regarding outcomes. The first signs of impaired heart function may appear during exercise testing. The aim of the present study was to establish mean values for maximal oxygen uptake in adults with various congenital heart diseases. Patients from 6 major diagnostic groups were identified, including patients with atrial septal defect (ASD, n = 93), transposition of the great arteries corrected with the Mustard procedure (n = 84), congenitally corrected transposition of the great arteries (CCTGA, n = 41), Tetralogy of Fallot (n = 168), Ebstein's anomaly (n = 37), and Modified Fontan procedure (n = 52). Diminished maximal oxygen uptake was found in all diagnostic groups across age compared with healthy subjects. A significant decrease in maximal oxygen uptake with aging was found in those with ASD (p <0.0001), CCTGA (p = 0.01), and Tetralogy of Fallot (p <0.0001). There was no significant decline, however, in Ebstein's anomaly (p = 0.270), Fontan procedure (p = 0.182), and in the Mustard patients (p = 0.188). All patients achieved significantly lower heart rates than predicted (mean for all groups, p <0.0001). Forced vital capacity values (3.51 L, mean SD +/- 1.02) were lower than predicted values (4.10 L, mean SD +/- 0.90, p <0.0001) for all patients groups except those with ASD. Mean values, however, were within the accepted 20% range of variance. This study showed diminished aerobic capacity in all diagnostic groups when compared with a healthy population. The maximal oxygen uptake values across age groups can be used as reference values in patients with similar diagnoses and as the basis for further research.

Right and left ventricular systolic function late after repair of tetralogy of Fallot.

Right ventricular (RV) dysfunction has adverse effects on long-term outcome in patients with repaired tetralogy of Fallot (TOF). We employed serial radionuclide angiography (RNA) to examine RV and left ventricular (LV) systolic function in adults late after TOF repair and its relation to clinical outcome. We reviewed 10-year records of 95 patients (53 men) with TOF followed in our clinic (mean age at repair 12.6 +/- 10.5 years, mean age at last follow-up 37.7 +/- 9.8 years) who underwent at least 2 RNAs between 1987 and 1997. Most patients were well by the end of the study (80% were New York Heart Association class I, 17% were class II, and 3% were in class III). Sixteen patients experienced sustained tachyarrhythmias (8 had atrial; 8 patients had ventricular). One patient died suddenly. Fifteen patients underwent RV outflow reoperations (15 underwent pulmonary valve replacement; 7 had relief of RV outflow obstruction); RV systolic function during exercise in these 15 patients was significantly impaired before and returned to similar levels after surgery, compared with the rest of the patients. Overall, RV and LV function remained stable in the whole group at a mean interval of 5.7 +/- 2.2 years between first and last RNA. This group of closely followed adults with TOF remained well over 10 years with a low incidence of sudden death and stable RV and LV systolic function, despite a relatively large number of RV outflow reoperations. Aggressive intervention for right-sided hemodynamic abnormalities may have contributed to this outcome. Preserved ventricular function may herald a favorable long-term outlook in this group.