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Helmut Singer

Publications and source records attributed to Helmut Singer.

18 recordsLinked to original sources
PubMed2006

Impact of cardiac surgery on plasma levels of B-type natriuretic peptide in children with congenital heart disease.

OBJECTIVE: To examine prospectively the effect of cardiac surgery on plasma concentration of B-type natriuretic peptide (BNP) in children with congenital heart disease. SETTING: Tertiary referral center. METHODS: BNP plasma concentration was measured by sandwich immunoassay (Biosite) in 65 consecutive patients with congenital heart disease (age 4 days to 17.1 years, mean (S.D.) age 3.6 (4.7) years, median age 1.0 years) on the day before and after surgical therapy. BNP levels were compared to perioperative data and to healthy subjects. RESULTS: BNP increased significantly (p<0.001) after cardiac surgery from median 31 pg/ml (mean 189 pg/ml) to median 453 pg/ml (mean 607 pg/ml) and remained significantly elevated during the first week (p<0.001). After a first peak mean (S.D.) 1.3 (0.7) days after surgery, there was a significant decrease of plasma BNP followed by a second peak 5.1 (1.1) days after surgery. Postoperative BNP plasma concentration was correlated to BNP before surgery (r=0.58, p<0.001), to cardiopulmonary bypass duration (r=0.52, p<0.001) and to serum lactate concentration at the first day after surgery (r=0.49, p<0.001). CONCLUSIONS: In children with congenital heart defects plasma BNP increased immediately after cardiac surgery despite haemodynamic unloading. The correlation to cardiopulmonary bypass time and serum lactate concentration and the similarity between the pattern of BNP release after surgery and after myocardial ischaemia might be explained by a cytoprotective role for BNP after cardiac surgery.

Adolescent↗
PubMed2006

B-type natriuretic peptide in paediatric patients with congenital heart disease.

AIMS: To examine the diagnostic value of B-type natriuretic peptide (BNP) plasma concentration in congenital heart disease. METHODS AND RESULTS: BNP was measured in 288 consecutive patients (mean age 6.0 +/- 6.4 years) with left-to-right shunt, left or right heart obstruction, tetralogy of Fallot, functionally univentricular heart, or impaired left ventricular function and compared with age- and gender-specific normal values, and to haemodynamic and echocardiographic data. BNP increased with decreasing left ventricular shortening fraction (r = -0.80; P < 0.001). In patients with left-to-right shunt, BNP was increased (mean SDS +1.64; P < 0.001) and positively correlated (P < 0.001) to shunt volume (r = 0.66), systolic right ventricular pressure (r = 0.69), mean pressure of the pulmonary artery (r = 0.66), and pulmonary resistance (r = 0.59). There was no correlation between BNP and invasive pressure gradient or extent of ventricular hypertrophy in patients with left or right heart obstruction. In patients with tetralogy of Fallot, BNP was not significantly increased. Patients with functionally univentricular heart had elevated BNP plasma levels (mean SDS +1.39; P < 0.001) without decrease after volume unloading by cavopulmonary connection. CONCLUSION: In children with congenital heart defects, plasma BNP correlates closely to ventricular function. BNP plasma levels do not reflect directly the extent of ventricular pressure or volume work, but mirror the impairment of the loaded ventricles. Normal BNP cannot exclude pathology, but reflects a compensated status of the heart.

Blood Pressure↗
PubMed2006

Decreasing ratio of plasma N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide according to age.

BACKGROUND: B-type natriuretic peptide (BNP) and the N-terminal fragment of proBNP (NT-proBNP) seem to be useful diagnostic tools also in children with cardiac disease. Recent data suggest that plasma levels of both peptides show different patterns from infancy to adolescence. AIM: To investigate the relationship of BNP and NT-proBNP in children and adolescents according to age. SUBJECTS AND METHODS: In 46 individuals without cardiac disease (22 males, 24 females, aged 0.4-17.5 years) and 30 patients with congenital heart disease (17 males, 13 females, aged 0.2-18.4 years), plasma levels of BNP and NT-proBNP were measured in the same sample (triage BNP assay, Biosite and Elecsys NT-proBNP assay, Roche Diagnostics). RESULTS: The range of BNP plasma levels was 5-32 pg/ml in individuals without heart disease and 5-1300 pg/ml in the patient group, the range of NT-proBNP was 10-298 pg/ml and 30-18,966 pg/ml, respectively. In both groups, the ratio NT-proBNP/BNP decreased with increasing age (P<0.001). CONCLUSION: Although proBNP is cleaved into the two fragments NT-proBNP and BNP, there is a decreasing ratio of NT-proBNP/BNP with increasing age caused probably by age-dependent differences in the metabolic clearance of both peptides. This has to be considered in comparison studies on BNP and NT-proBNP regarding their benefit to paediatric cardiology.

Adolescent↗
PubMed2005

First successful implantation of a biodegradable metal stent into the left pulmonary artery of a preterm baby.

Stent implantation in the youngest patients with a congenital heart disease implicates limitations concerning further vessel growth, the need of staged redilation, and later surgical removal. The search to overcome these restrictions led to open stent designs, with a wide adaptability to the vessel growth and recently to the development of bioabsorbable stent materials. A preterm baby born at 26 weeks of gestation was referred to our clinic following inadvertent ligation of the left pulmonary artery. Despite efficient debanding, the left lung perfusion was absent. Implantation of a biodegradable 3 mm magnesium stent was performed in a hybrid procedure when the baby weighed 1.7 kg. Reperfusion of the left lung was established and persisted throughout the 4-month follow-up period during which the gradual degradation process of the stent completed. Additional interventions, should they become necessary, seem not to be limited. Despite the small size of the baby, the degradation process was clinically well tolerated. The mechanical and degradation characteristics of the magnesium stent proved to be adequate to secure reperfusion of the previously occluded left pulmonary artery. Bioabsorbable stents with different diameters may help develop new strategies in the therapy of vessel stenosis in pediatric patients.

Absorbable Implants↗
PubMed2005

Cardiovascular anomalies in children and young adults with Ullrich-Turner syndrome the Erlangen experience.

BACKGROUND: Females with Ullrich-Turner syndrome (UTS) have typical clinical features such as short stature, ovarian failure, visible dysmorphic stigmata, and abnormalities in different organs such as kidney or heart. HYPOTHESIS: The aim of the present study was to analyze the distribution, prevalence, and relative risk of cardiovascular anomalies (CVA) in females with Ullrich-Turner syndrome (UTS) seen at one single center compared with that of the regional Bavarian population. METHODS: The associations between CVA and karyotype were determined. In all, 117 girls and women with UTS, aged between 3 and 43 years (median 17.4 years) were studied retrospectively. The detailed cardiologic status including echocardiography was available in all patients. The prevalences of each cardiovascular anomaly were determined. On the basis of published epidemiologic data of CVA in Bavarian children, we assessed the relative risks of each CVA. RESULTS: Thirty-five (29.9%) girls with UTS had at least one CVA. In all of these CVAs, coarctation of the aorta and bicuspid aortic valve occurred most often (18.5% each). The aortic malformations represented over two-thirds of all CVA (72.8%), whereas anomalies of the septum (8.6%), mitral valve (6.2%), pulmonary veins (4.9%), and other locations together accounted for the other third. Bicuspid aortic valve and partial anomalous pulmonary venous drainage were associated with the highest relative risk (RR) (3603 and 1293, respectively) compared with the Bavarian population. The overall RR of CVA was 48.7. Of the 117 girls and women examined, 64 (54.7%) had complete monosomy 45 X. CONCLUSIONS: Our data demonstrate that about every third female with UTS is affected with at least one CVA, mainly left sided and associated with aortic structures. Our results underline the necessity of thorough cardiologic evaluation.

Adolescent↗
PubMed2004

Laterality of the aortic arch and anomalies of the subclavian artery-reliable indicators for 22q11.2 deletion syndromes?

UNLABELLED: A variety of cardiac defects, encompassing truncus arteriosus, tetralogy of Fallot, pulmonary atresia with ventricular septal defect and interrupted aortic arch, are generally summarised as conotruncal malformations. Patients with these cardiac defects were frequently found to have a common microdeletion on chromosome 22, the so-called monosomy 22q11.2. The aim of our study was to determine whether the laterality of the aortic arch or the presence of subclavian artery anomalies (SAA) represent markers for monosomy 22q11.2 in these patients. 170 patients with these cardiac anomalies were recruited at presentation in the paediatric cardiology units of two tertiary referral centres from 1994 until 2003. Of the 170 children and young adults, 33 had interrupted aortic arch, 35 tetralogy of Fallot, 31 truncus arteriosus communis and 71 pulmonary atresia with ventricular septal defect. All were screened for monosomy 22q11.2 and the results were correlated with the laterality of the aortic arch and the presence of SAA contralateral to the aortic arch (aberrant origin from the descending aorta, isolation, distal ductal origin from the pulmonary artery and cervical origin of the right subclavian artery). Monosomy 22q11.2 was present in 59/170 patients (35%). A left aortic arch (LAA) was found in 118 (69%), a right aortic arch (RAA) in 52 (31%) patients. Almost 50% of the patients with RAA (46%), but only 30% of the patients with LAA had monosomy 22q11.2 ( P=0.054). A total of 47 patients (28%) had an anomaly of the subclavian artery, 81% of whom had monosomy 22q11.2. This deletion was found in decreasing percentage in patients with LAA+SAA (85%) >RAA+SAA (75%) >RAA without SAA (28%) >LAA without SAA (13%). CONCLUSION: In patients with conotruncal malformations, anomalies of the subclavian arteries are the most important anatomical marker for the presence of monosomy 22q11.2, independent of the laterality of the aortic arch. Therefore, we recommend cytogenetic testing for this microdeletion in all patients with subclavian artery anomalies and conotruncal malformations.

Adolescent↗
PubMed2004

Search for somatic 22q11.2 deletions in patients with conotruncal heart defects.

A wide range of clinical variability in patients with 22q11.2 deletions has been demonstrated in numerous studies. Nevertheless, it is still an open question if major genetic factors contribute to clinical expression. Therefore one aim of this study was to investigate, if patients with 22q11.2 deletion and conotruncal heart defects show a "second hit" somatic 22q11.2 deletion in tissue from the conotruncus, heart vessels or thymus. The second aim was to analyse patients with conotruncal heart defects without 22q11.2 deletion in blood cells for somatic deletion mosaicism. We were able to study tissue samples from heart surgery from 23 patients, 9 of whom had 22q11 deletions by FISH analysis on metaphase spreads from peripheral lymphocytes. Analysis of 18 polymorphic markers from the 22q11.2 region in DNA prepared from thymus and/or heart vessels and/or conotruncus tissue and peripheral lymphocytes in each patient did not show any allelic loss. Thus somatic 22q11.2 deletions apparently do not play a major role in conotruncal heart defects in patients with or without germ line 22q11.2 deletion.

Child↗
PubMed2004

Genotype-phenotype correlations in Noonan syndrome.

OBJECTIVE: To study genotype-phenotype correlations in a cohort of clinically well-characterized pediatric patients with Noonan syndrome (NS). Study design Fifty-seven unrelated patients with the clinical diagnosis of NS ascertained according to standardized inclusion criteria were prospectively enrolled. Mutational analysis was performed by direct sequencing of the entire coding sequence of the PTPN11 gene. RESULTS: Sixteen known and 3 novel PTPN11 mutations could be detected in 60% of index patients, in all familial and in 52% of the sporadic cases. Presence of pulmonic stenosis, short stature, easy bruising, and thorax deformities was significantly associated with a PTPN11 mutation, whereas cardiomyopathy was more common in patients without a mutation. On average, PTPN11 mutation-negative probands fulfilled fewer clinical criteria of NS, but more than half-among them all with cardiomyopathy-had the full clinical picture of NS indistinguishable from typical cases with PTPN11 mutation. CONCLUSIONS: The phenotype of NS due to PTPN11 mutations is clinically unambiguous in the majority of patients and represents a highly penetrant trait. Individuals with the clinical diagnosis of NS but without a PTPN11 mutation presumably represent a heterogeneous group in which patients with cardiomyopathy appear to constitute an interesting subgroup for future research.

Adolescent↗
PubMed2004

Pulsating thoracic tumor caused by extragenital endometriosis in a patient with Noonan syndrome.

We present the case of a 36-year-old woman with Noonan syndrome and congenital heart disease in whom extragenital endometriosis caused an extraordinarily large jelly-like paracardiac and abdominal mass. Protrusion through an intercostal space caused a pulsating subcutaneous tumor on the left lateral thoracic wall. The patient never complained of menstruation-related pain. Histology obtained during several prior surgical interventions had been inconclusive. Thus definitive diagnosis was delayed for years. A literature review revealed no known association between Noonan syndrome and endometriosis.

Abdomen↗
PubMed2003

No influence of surgical stress on postoperative leptin gene expression in different adipose tissues and soluble leptin receptor plasma levels.

UNLABELLED: As part of the postsurgical stress response, plasma leptin levels increase in-between 12 h postoperatively. OBJECTIVE: To study the kinetics of leptin gene expression in different adipose tissues before and after severe surgical trauma in children and adults. METHODS: In 22 adults and 23 children with cardiac and 19 adult patients with abdominal surgery, we measured plasma leptin concentrations preoperatively, 4 and 10-17 h postoperatively and quantified leptin mRNA expression by TaqMan real-time PCR in adipose tissue taken at the beginning and the end of surgery from subcutaneous, intrathoracic, omental and mesenteric fat. Plasma-soluble leptin receptor levels were measured in 23 children after cardiosurgery. RESULTS: Plasma leptin levels doubled between 4 and 10-17 h postoperatively in adults (p < 0.001) as well as in children (p = 0.0002) with cardiac surgery. After abdominal surgery, 10-17 h postoperatively, plasma leptin concentrations increased significantly (p < 0.05). During the operation, leptin gene expression did not change in neither of the patient groups. Plasma-soluble leptin receptor levels decreased immediately after the onset of surgery and remained unchanged thereafter. CONCLUSIONS: Leptin gene expression is not up-regulated during surgery. The measured increase in plasma leptin after surgery does not result from elevated levels of soluble leptin receptor but may follow an up-regulation of leptin gene expression later after the operation due to postsurgical metabolic changes.

Abdomen↗
PubMed2002

Hypoparathyroidism in conotruncal heart defects.

UNLABELLED: This retrospective study was designed to evaluate serum levels of intact parathyroid hormone and calcium in patients with conotruncal heart defects with or without microdeletion 22q11.2 in order to investigate a correlation between various types of conotruncal heart defect and hypoparathyroidism. A total of 67 patients with truncus arteriosus, tetralogy of Fallot, pulmonary atresia and ventricular septal defect, interrupted aortic arch or vascular ring were included of whom 28 had a 22q11.2 deletion (Group I) and 39 did not (Group II). In two patients of Group I and in one patient of Group II, parathyroid hormone level was decreased with normal serum calcium levels. No patient of Group II showed hypocalcaemia. In Group I, complete hypoparathyroidism with low parathyroid hormone and hypocalcaemia occurred in seven patients; 5 patients had bilateral anomalies of the right and the left 4th aortic arch derivates. In addition to an interrupted aortic arch type B or a high aortic arch, the contralateral subclavian artery arose cervically, high thoracically or anomalously from the descending aorta. Two patients had unilateral anomalies of the 4th aortic arch system: The origin of the right subclavian artery was cervical or from the descending aorta. CONCLUSION: Hypoparathyroidism occurred in 7 of our 28 patients with conotruncal heart defect and monosomy 22q11.2 and was associated with an extended regression of the 4th aortic arch development on both sides of the aortic arch system.

Adolescent↗
PubMed2001

Cardiopulmonary bypass surgery does not further increase elevated serum leptin concentrations after major surgery.

OBJECTIVE: The objective of the present study was to examine the impact of major heart surgery with cardiopulmonary bypass (CPB) in childhood on serum leptin concentrations in relation to plasma cortisol, epinephrine, norepinephrine, and insulin. DESIGN: Controlled, prospective study. SETTING: Intensive care unit of a university hospital. Patients and INTERVENTIONS: We enrolled 20 pediatric patients undergoing open heart surgery and 20 children with major surgery not necessitating CPB (surgical control group). Leptin was measured by radioimmunoassay, cortisol and insulin were measured by chemiluminescence, and epinephrine and norepinephrine were measured by high-pressure liquid chromatography. MEASUREMENTS AND MAIN RESULTS: In the CPB group, leptin dropped from 0.4 +/- 0.1 preoperatively (mean +/- sem) to 0.2 +/- 0.1 ng/mL intraoperatively (p <.05). It increased to 1.6 +/- 0.7 ng/mL 12 hrs after surgery (p <.01) and declined thereafter. In the surgical controls, leptin rose from 0.5 +/- 0.2 ng/mL before surgery to 1.8 +/- 0.8 ng/mL 12 hrs after surgery (p =.001). In both groups, plasma cortisol, insulin, and epinephrine significantly increased after surgery. There was no relationship between the maximum increase of serum leptin and the other hormones. CONCLUSIONS: Patients with CPB surgery and non-CPB surgery show a similar increase in serum leptin, indicating that sepsislike inflammatory syndrome does not further increase elevated leptin concentrations following major surgery. In this complex situation, serum leptin does not appear to be merely regulated by its known stimuli and suppressors.

Journal Article↗