[Infective endocarditis in patients with congenital heart disease]. / Endocardite infettiva nei cardiopatici congeniti.

The incidence of infective endocarditis (IE) in patients with congenital heart disease (CHD) is higher than in general population; this is a major problem considering the continuous expansion of such group of patients. Generally the more complex is the congenital heart disease the higher is the risk of IE. The aetiology, clinical features, complications, basis for diagnosis and treatment of IE in CHD patients don't differ from those in acquired cardiac disease; however, right-sided IE is more frequent in CHD patients. Due to the complex anatomy or presence of artificial material in many CHD, the transesophageal echocardiogram is extremely useful although echocardiographic assessment remains difficult. Prognosis is better than in other forms of IE with a mortality rate <10%. Primary prevention is crucial: a good oral-dental hygiene and regular dental review are as important as antibiotic prophylaxis; however this awareness in the CHD population is still not satisfactorily spread due to an educational problem. New IE guidelines from International Cardiology Societies emphasize the role of primary prevention and limit antibiotic prophylaxis to the highest risk patients undergoing the highest risk procedures. This article reviews the main reasons justifying the revision of previous IE guidelines, focuses on criteria to select CHD patients requiring antibiotic prophylaxis and gives information about antibiotic therapy to use.

[Cardiopulmonary exercise test in adults with congenital heart disease]. / Prova cardiopolmonare in pazienti adulti con cardiopatia congenita.

Cardiopulmonary exercise testing (CPET) gives important information about functional capacity by direct measurement of exercise respiratory gas exchange. It provides assessment of the integrative exercise responses involving the cardiovascular, respiratory and muscle-skeletal systems which are not adequately investigated through the measurement of individual organ system function. CPET involves measurements of oxygen uptake (VO2), carbon dioxide production (VCO2) and several ventilatory measures. CPET is increasingly being used as a clinical tool to determine functional capacity, prognosis and potential need for medical or surgical interventions in patients affected by congenital heart disease (CHD). Also in this population, peak VO2 and slope VE/VCO2 are the most predictive parameters in terms of mortality and need of hospitalization. Cyanotic patients with Esisenmenger syndrome show the worst functional limitation and consequently the worst prognosis. This article provides basic and practical information about CPET and focuses on its interpretation in patients with CHD.

A new 2D-based method for myocardial velocity strain and strain rate quantification in a normal adult and paediatric population: assessment of reference values.

BACKGROUND: Recent advances in technology have provided the opportunity for off-line analysis of digital video-clips of two-dimensional (2-D) echocardiographic images. Commercially available software that follows the motion of cardiac structures during cardiac cycle computes both regional and global velocity, strain, and strain rate (SR). The present study aims to evaluate the clinical applicability of the software based on the tracking algorithm feature (studied for cardiology purposes) and to derive the reference values for longitudinal and circumferential strain and SR of the left ventricle in a normal population of children and young adults. METHODS: 45 healthy volunteers (30 adults: 19 male, 11 female, mean age 37 +/- 6 years; 15 children: 8 male, 7 female, mean age 8 +/- 2 years) underwent transthoracic echocardiographic examination; 2D cine-loops recordings of apical 4-four 4-chamber (4C) and 2-chamber (2C) views and short axis views were stored for off-line analysis. Computer analyses were performed using specific software relying on the algorithm of optical flow analysis, specifically designed to track the endocardial border, installed on a Windows based computer workstation. Inter and intra-observer variability was assessed. RESULTS: The feasibility of measurements obtained with tissue tracking system was higher in apical view (100% for systolic events; 64% for diastolic events) than in short axis view (70% for systolic events; 52% for diastolic events). Longitudinal systolic velocity decreased from base to apex in all subjects (5.22 +/- 1.01 vs. 1.20 +/- 0.88; p < 0.0001). Longitudinal strain and SR significantly increased from base to apex in all subjects (-12.95 +/- 6.79 vs. -14.87 +/- 6.78; p = 0.002; -0.72 +/- 0.39 vs. -0.94 +/- 0.48, p = 0.0001, respectively). Similarly, circumferential strain and SR increased from base to apex (-21.32 +/- 5.15 vs. -27.02 +/- 5.88, p = 0.002; -1.51 +/- 0.37 vs. -1.95 +/- 0.57, p = 0.003, respectively). Values of global systolic SR, both longitudinal and circumferential, were significantly higher in children than in adults (-1.3 +/- 0.2, vs. -1.11 +/- 0.2, p = 0.006; -1.9 +/- 0.6 vs. -1.6 +/- 0.5, p = 0.0265, respectively). No significant differences in longitudinal and circumferential systolic velocities were identified for any segment when comparing adults with children. CONCLUSION: This 2D based tissue tracking system used for computation is reliable and applicable in adults and children particularly for systolic events. Measured with this technology, we have established reference values for myocardial velocity, Strain and SR for both young adults and children.

Serum NT-proBNP Levels Are Not Related to Vitamin D Status in Young Patients with Congenital Heart Defects.

CONTEXT: Hypovitaminosis D frequently occurs in early life and increases with age. Vitamin D has been suggested to influence cardiac performance and N-terminal-pro-type B natriuretic peptide (NT-proBNP) release in adults with heart failure. OBJECTIVES: To assess the vitamin D status and the impact of hypovitaminosis D on circulating NT-proBNP levels in young patients with congenital heart defects (CHD). DESIGN AND PATIENTS: This cross-sectional study included the assessment of serum 25-hydroxyvitamin D (25OHD), parathyroid function markers, and NT-proBNP levels in a series of 230 young in-patients (117 females, 113 males; 6.4 (4.0-9.1) years (median, interquartile range)) with CHD. RESULTS: Serum 25OHD levels <20 ng/mL were detected in 55.3% of patients. Optimal 25OHD levels (>30 ng/mL) occurred in 25% of patients. Serum 25OHD levels inversely correlated with age (r = -0.169, P = 0.013) and height standard deviation score (r = -0.269, P = 0.001). After correction for age, 25OHD negatively correlated with serum PTH levels (ß = -0.200, P = 0.002). PTH levels above the upper quartile (44 pg/mL) occurred in 32% of hypovitaminosis D patients. Serum NT-proBNP levels were not correlated with 25OHD and PTH levels. CONCLUSIONS: Half of the young CHD patients were diagnosed with 25OHD deficiency and a third of hypovitaminosis D patients experienced hyperparathyroidism. Nonetheless, serum NT-proBNP levels were not associated with hypovitaminosis D as well as hyperparathyroidism.

The tracking control system of the VLT Survey Telescope.

The VLT survey telescope is the latest telescope installed at European Southern Observatory's Paranal observatory that is considered one of the best sites for optical astronomy for the excellent seeing conditions. The exceptional quality of the site imposes tight requirements for the telescope tracking system that shall perform very well to fully exploit the extreme sharpness of the Chilean sky. We describe the specific solutions adopted for pointing, servo and guiding systems and the results obtained during the commissioning of the telescope. The hardware implementation relies on industry components and the control solutions privilege both the performance and the future maintainability of the system.

Increased risk for non-autoimmune hypothyroidism in young patients with congenital heart defects.

CONTEXT: Newborns with congenital hypothyroidism (CH) have an increased risk for congenital heart defects (CHD) due to a common embryonic developmental program between thyroid gland and heart and great vessels. OBJECTIVE: Our objective was to investigate the prevalence and origin of thyroid disorders in young patients with CHD. DESIGN AND SETTING: We conducted a prospective observational study between January 2007 and January 2009 in academic Pediatric Cardiosurgery and Endocrinology. PATIENTS: Patients included 324 children (164 males, 160 females, aged 0.2-15.4 yrs) with CHD. INTERVENTION: Subjects underwent hormonal and genetic screening. MAIN OUTCOME MEASURES: Serum TSH and thyroid hormone levels were assessed. RESULTS: Two CHD patients were diagnosed with CH at the neonatal screening (1:162). Mild hypothyroidism (serum TSH > 4.0 µU/ml) was diagnosed and confirmed 6 months later [TSH = 5.4 ± 1.5 µU/ml; free T(4) = 1.3 ± 0.2 ng/dl (normal values 0.8-1.9)] in 37 children (11.5%) who were negative at neonatal screening. Hypothyroidism was not related to type of CHD, whereas TSH levels positively correlated with serum N-terminal pro-type B natriuretic peptide levels. Biochemical and ultrasound findings consistent with thyroid autoimmunity were present in three of 37 hypothyroid children (8.1%). One patient had hemiagenesis (2.7%). Variations in candidate genes were screened in CHD patients. NKX2.5 coding sequence was normal in all samples. A 3-Mb microdeletion in 22q11.2 was detected in three patients (8.3%), whereas only known polymorphisms were identified in TBX1 coding sequence. CONCLUSIONS: CHD patients have an increased risk for both CH (10-fold higher) and acquired mild hypothyroidism (3-fold higher). Unrecognized mild hypothyroidism may negatively affect the outcome of CHD children, suggesting that thyroid function should be repeatedly checked. Thyroid autoimmunity and 22q11.2 microdeletions account for small percentages of these cases, and still unknown mechanisms underline such a strong association.

Energy-sharing asymmetries in ionization by positron impact.

The triply differential cross section of molecular hydrogen for ionization by 50 eV positrons has been determined, for the first time, for both the ejected electron in coincidence with the remnant ion and for the scattered projectile. Asymmetries in the energy sharing between the two light particles in the final state are observed, with the electron spectrum being shifted to significantly lower (and the scattered positron to correspondingly higher) energies than expected. A similar shape is observed in the case of the ejected electron spectrum from a helium target at the same excess energy.

Cephalosporin-induced Hemolytic Anemia in a Sicilian Child.

A 27-month-old child developed acute hemolysis on two occasions after the administration of cephalosporin. On the first occasion, hemolysis was intravascular and was due to the formation of complexes between antibodies and the drug, which bound to red blood cells and caused severe hemolysis. On the second occasion, hemolysis was extravascular and was probably due to antibody-dependent cell mediated cytotoxicity. Marked increases in levels of CD19(+), and CD57(+) CD8(+) cells were detected among the subpopulations of the patient's lymphocytes but only in the level of CD19(+) cells from the patient's father, after incubation of a sample of whole blood with a solution of cephalosporins. These results might explain the differences between the immune response of the patient and those of other members of his family and of an unrelated control.

Cephalosporin-induced Hemolytic Anemia in a Sicilian Child; Erythropoiesis.

A 27-month-old child developed acute hemolysis on two occasions after the administration of cephalosporin. On the first occasion, hemolysis was intravascular and was due to the formation of complexes between antibodies and the drug, which bound to red blood cells and caused severe hemolysis. On the second occasion, hemolysis was extravascular and was probably due to antibody-dependent cell-mediated cytotoxicity. Marked increases in levels of CD(19) (+) and CD(57) (+) CD(8) (+) cells were detected among the subpopulations of the patient's lymphocytes but only in the level of CD(19) (+) cells from the patient's father, after incubation of a sample of whole blood with a solution of cephalosporins. These results might explain the differences between the immune response of the patient and those of other members of his family and of an unrelated control.