Transcriptional defect of an inherited NKX2-5 haplotype comprising a SNP, a nonsynonymous and a synonymous mutation, associated with human congenital heart disease.

Germline mutations in cardiac-specific transcription factor genes have been associated with congenital heart disease (CHD) and the homeodomain transcription factor NKX2-5 is an important member of this group. Indeed, more than 40 heterozygous NKX2-5 germline mutations have been observed in individuals with CHD, and these are spread along the coding region, with many shown to impact protein function. In pursuit of understanding causes of CHD, we analyzed n = 49 cardiac biopsies from 28 patients and identified by direct sequencing two nonsynonymous NKX2-5 alterations affecting alanine 119, namely c.356C>A (p.A119E) and c.355G>T, (p.A119S), in patients with AVSD and HLHS, respectively. In functional assays, a significant reduction in transcriptional activities could be determined for the NKX2-5 variants. Importantly, in one family the mother, besides p.A119E, carried a synonymous mutant allele in the homeodomain (c.543G>A, p.Q181), and a synonymous dbSNP (c.63A>G, p.E21) in the transactivation domain of the protein, that were transmitted to the CHD daughter. The presence of these variants in-cis with the p.A119E mutation led to a further reduction in transcriptional activities. Such difference in activity may be in part related to reduced protein expression for the double variant c.356C>A and c.543G>A. We propose changes in mRNA stability and folding, due to a silent mutation and a dbSNP in the NKX2-5 coding region to contribute to the functional defect. Although the clinical significance of the NKX2-5 haplotype identified in the CHD patients remains to be ascertained, we provide evidence of an interaction of a dbSNP, with synonymous and nonsynonymous mutations to negatively impact NKX2-5 transcriptional activity.

Comparison of late results of arterial switch versus atrial switch (mustard procedure) operation for transposition of the great arteries.

Two decades after surgery for transposition of the great arteries, the clinical status, cardiac function, cardiorespiratory performance, and neurohormonal activity of patients who underwent either atrial switch (Mustard) operations or arterial switch operations (ASOs) were compared. Sixty-two patients with simple transposition of the great arteries who underwent either Mustard (n = 34) or ASO (n = 28) procedures were included in this cross-sectional study. Following the same study protocol, clinical workup including echocardiography, stress testing, and blood work was completed for all patients. Mean ages in the 2 groups were comparable, at 20.6 ± 2.1 and 20.6 ± 3.4 years in the ASO and Mustard groups, respectively. All ASO patients were in New York Heart Association class I, whereas 59% of Mustard patients were in class II or III. Peak oxygen uptake was higher in ASO patients (percentage of predicted 80% vs 69%, p <0.01). Compared with healthy subjects, the mean Tei index for systemic ventricle was high in the 2 groups, but this parameter was significantly higher in Mustard than ASO patients (0.60 ± 0.16 vs 0.47 ± 0.14, p <0.01). The median plasma N-terminal pro-brain natriuretic peptide level in ASO patients was within the normal range, but the Mustard group had significantly higher levels (42 ng/ml [range 18 to 323] vs 172 ng/ml [range 26 to 1,018], p <0.0001). In conclusion, this cross-sectional assessment 2 decades after surgery reveals better clinical status in patients who underwent ASO compared with Mustard patients. This holds in terms of cardiac function, cardiorespiratory performance, and neurohormonal activity.

In-line filtration reduces severe complications and length of stay on pediatric intensive care unit: a prospective, randomized, controlled trial.

PURPOSE: Particulate contamination due to infusion therapy carries a potential health risk for intensive care patients. METHODS: This single-centre, prospective, randomized controlled trial assessed the effects of filtration of intravenous fluids on the reduction of complications in critically ill children admitted to a pediatric intensive care unit (PICU). A total of 807 subjects were randomly assigned to either a control (n = 406) or filter group (n = 401), with the latter receiving in-line filtration. The primary endpoint was reduction in the rate of overall complications, which included the occurrence of systemic inflammatory response syndrome (SIRS), sepsis, organ failure (circulation, lung, liver, kidney) and thrombosis. Secondary objectives were a reduction in the length of stay on the PICU and overall hospital stay. Duration of mechanical ventilation and mortality were also analyzed. FINDINGS: Analysis demonstrated a significant reduction in the overall complication rate (n = 166 [40.9 %] vs. n = 124 [30.9 %]; P = 0.003) for the filter group. In particular, the incidence of SIRS was significantly lower (n = 123 [30.3 %] vs. n = 90 [22.4 %]; P = 0.01). Moreover the length of stay on PICU (3.89 [95 % confidence interval 2.97-4.82] vs. 2.98 [2.33-3.64]; P = 0.025) and duration of mechanical ventilation (14.0 [5.6-22.4] vs. 11.0 [7.1-14.9] h; P = 0.028) were significantly reduced. CONCLUSION: In-line filtration is able to avert severe complications in critically ill patients. The overall complication rate during the PICU stay among the filter group was significantly reduced. In-line filtration was effective in reducing the occurrence of SIRS. We therefore conclude that in-line filtration improves the safety of intensive care therapy and represents a preventive strategy that results in a significant reduction of the length of stay in the PICU and duration of mechanical ventilation (ClinicalTrials.gov number: NCT00209768).

Comparison of transpulmonary thermodilution and ultrasound dilution technique: novel insights into volumetric parameters from an animal model.

Especially in critically ill children with cardiac diseases, fluid management and monitoring of cardiovascular function are essential. Ultrasound dilution technique (UDT) was recently introduced to measure cardiac output (CO) and volumetric parameters, such as intrathoracic and end-diastolic blood volume. We compared UDT with the well-established transpulmonary thermodilution (TPTD) method (PiCCO) for determining CO measurements and derived volumes in a juvenile animal model. Experiments were performed in 18 ventilated, anesthetized piglets during normovolemia and after isovolemic hemodilution. At baseline and 20 min after each step of isovolemic hemodilution, 3 independent measurements of CO and volumetric parameters were conducted with TPTD and UDT, consecutively, under hemodynamically stable conditions. We observed comparable results for CO measurements with both methods (mean 1.98 l/min; range 1.12-2.87) with a percentage error of 17.3% (r = 0.92, mean bias = 0.28 l/min). Global end-diastolic volume (GEDV) and intrathoracic blood volume (ITBV) by TPTD were almost two times greater than analogous volumes [central blood volume (CBV); total end-diastolic volume (TEDV)] quantified by UDT (CBV = 0.58 × ITBV + 27.1 ml; TEDV = 0.48 × GEDV + 23.1 ml). CO measurements by UDT were found to be equivalent and hence interchangeable with TPTD. Discrepancies in volumetric parameters could either be due to the underlying algorithm or different types of indicators (diffusible vs. nondiffusible). Compared with the anatomically defined heart volume, TPTD seems to overestimate end-diastolic volumes. Future studies will be necessary to assign these results to critically ill children and to validate volumetric parameters with reference techniques.

Safety and efficiency of chronic ACE inhibition in symptomatic heart failure patients with a systemic right ventricle.

BACKGROUND: ACE inhibition is an established treatment regimen in patients with congestive heart failure due to left ventricular dysfunction which improves morbidity and mortality. However, little is known about the beneficial effects of ACE inhibition in adult patients after Mustard procedure for transposition of the great arteries with heart failure symptoms. Therefore, we investigated the effects of ACE inhibition in these patients on heart failure symptoms, echocardiographic diameters, NT-proBNP and exercise capacity. METHODS: In 14 patients (age 25.2 ± 3.5 years), after Mustard procedure for transposition of the great arteries (age at operation 1.1 ± 1.3 years) with heart failure NYHA II (New York Heart Association class), an ACE inhibition was initiated. At baseline and 13.3 ± 4.0 months after treatment with enalapril (10mg twice a day), echocardiography, exercise test and NT-proBNP measurements were performed and compared to an age- and sex-matched control group. RESULTS: Maximum oxygen uptake and echocardiographic parameters did not change significantly in both groups. However, NT-proBNP showed a significant decrease in the treatment group (242 ± 105 vs. 151 ± 93 ng/l, p=0.004), while in the control group a significant increase (120 ± 89 vs. 173 ± 149 ng/l, p<0.05) was observed. Furthermore, ACE inhibitor treatment did not result in a deterioration of heart failure symptoms or renal function. CONCLUSIONS: Thus, ACE inhibitor treatment of heart failure symptoms in patients with a systemic right ventricle is safe and reduces NT-proBNP levels significantly as a marker for ventricular overload. Nevertheless, larger scale trials are warranted to show effects on morbidity and mortality in this highly selected patient group.

Removal of temporary pacemaker after cardiac surgery in infants: A harmless procedure?

External pacemakers (PM) via temporary epicardial leads are routinely applied to infants and children during heart surgery, which usually, after an uneventful post surgical course, can be removed without complications. We report about two infants with complex congenital heart defects after cardiac surgery (arterial switch and Mustard operation for Transposition of the great arteries). Intraoperative these patients received temporary epicardial PM wires. Thirteen and 18 days post surgery, respectively, the PM wires were removed under electrocardiogram (ECG) monitoring. The patients showed acute ECG changes in terms of significant ST elevation during and after removing their pacing wires. Clinically, patients were stable and subsequent echocardiographic examination showed no evidence of myocardial dysfunction or pericardial effusion. In the course of time, patients showed no signs of arrhythmia or abnormal ECG changes. The decision to place temporary pacing wires during the cardiac surgery in patients with congenital heart defects should be considered carefully and their removal should occur under ECG monitoring as soon as the situation of the patient allows. It should be taken into consideration that a complication like this case may be related to delayed removal of temporary PM's leads.

Knowledge of congenital heart disease of mothers: presentation of a standardized questionnaire and first results.

OBJECTIVE: The "Hannover Inventory of Parental Knowledge of Congenital Heart Disease," a questionnaire for the assessment of knowledge about congenital heart disease (CHD) for use in parents, is presented, and the first results are reported. It consists of eight subscales covering general knowledge of cardiac functioning, signs and symptoms of the child's individual CHD before and after treatment, type of individual CHD and treatment, management of CHD, surveillance of deterioration, endocarditis, and physical activity. DESIGN: One hundred thirty-seven mothers completed the questionnaire immediately after their children underwent CHD surgery. RESULTS: The questionnaire has satisfactory psychometric properties. Knowledge on most dimensions was satisfactory, but it was rather poor with respect to important subscales as endocarditis and surveillance of deterioration. CONCLUSIONS: The questionnaire covers a range of relevant topics by taking the individual CHD into account. Parents have satisfactory knowledge of CHD in some areas, but knowledge about preventive behaviors turned out as rather poor. This needs to be improved in order to make parents capable to take their share of after-treatment care.

Growth differentiation factor 15: an additional diagnostic tool for the risk stratification of developing heart failure in patients with operated congenital heart defects?

BACKGROUND: Many young adults who have congenital heart defects develop heart failure despite corrective surgeries. Growth differentiation factor 15 (GDF-15) has an established role as a marker for risk stratification and mortality both in patients after acute myocardial infarction and in patients with heart failure. Our aim was to establish a role for GDF-15 for monitoring heart failure in operated congenital heart defects (ACHD). This potential biomarker was validated through comparison with maximal oxygen uptake (VO(2max)) and to another biomarker, N-terminal pro-brain natriuretic peptide (NT-proBNP). METHODS: A total of 317 ACHD patients (129 females) with an average age of 26.5 ± 8.5 years (mean ± SD) enrolled in the study. We studied the relation between GDF-15 and NT-proBNP and VO(2max%) (percent predicted for age and gender). The cutoffs for the groups were as follows: NT-proBNP <100, 100 to 300, and >300 pg/mL; VO(2max%) <65%, 65% to 85%, and >85% of predicted normal. RESULTS: Significant differences in mean GDF-15 levels were found between the NT-proBNP <100 and NT-proBNP >300 groups, as well as between the 100 to 300 and the >300 groups. For VO(2max%), significant differences were found in GDF-15 levels between <65% and >85% and between <65% and 65% to 85%, respectively. The lowest mean GDF-15 was found in groups with NT-proBNP <100 pg/mL and VO(2max%) >85%. The highest mean GDF-15 was found in the groups with NT-proBNP >300 pg/mL and VO(2max%) <65%. A subgroup analysis, including 82 patients with operated tetralogy of Fallot, showed that patients in the New York Heart Association I class have significantly lower NT-proBNP and GDF-15 level and markedly higher VO(2max) compared with the patients in higher New York Heart Association class. CONCLUSION: Growth differentiation factor 15 might be used as a surrogate marker for latent heart failure and could help to identify patients with ACHD who are at risk for developing heart failure, even if they are clinically asymptomatic.

Pulmonary valve replacement in chronic pulmonary regurgitation in adults with congenital heart disease: impact of preoperative QRS-duration and NT-proBNP levels on postoperative right ventricular function.

BACKGROUND: Chronic severe pulmonary regurgitation (PR) causes progressive right ventricular (RV) dysfunction and heart failure. Parameters defining the optimal time point for surgery of chronic PR are lacking. The present study prospectively evaluated the impact of preoperative clinical parameters, cardiorespiratory function, QRS duration and NT-proBNP levels on post operative RV function and volumes assessed by cardiac magnetic resonance imaging (CMR) in patients with chronic severe PR undergoing pulmonary valve replacement. METHODS AND RESULTS: CMR was performed pre- and 6 months postoperatively in 27 patients (23.6 ± 2.9 years, 15 women) with severe PR. Postoperatively, RV endsystolic (RVESVI) and enddiastolic volume indices (RVEDVI) decreased significantly (RVESVI pre 78.2 ± 20.4 ml/m² BSA vs. RVESVI post 52.2 ± 16.8 ml/m²BSA, p<0.001; RVEDVI pre 150.7 ± 27.7 ml/m²BSA vs. RVEDVI post 105.7 ± 26.7 ml/m²BSA; p<0,001). With increasing preoperative QRS-duration, postoperative RVEF decreased significantly (r=-0.57; p<0.005). Preoperative QRS-duration smaller than the median (156 ms) predicted an improved RVEF compared to QRS-duration≥ 156 ms (54.9% vs 46.8%, p<0.05). Multivariate analysis identified preoperative QRS duration as an independent predictor of postoperative RVEF (p<0.005). NT-proBNP levels correlated with changes in RVEDI (r=0.58 p<0,005) and RVESVI (r=0.63; p<0,0001). Multivariate analysis identified NT-proBNP levels prior to PVR as an independent predictor of volume changes (p<0.05). CONCLUSION: Valve replacement in severe pulmonary regurgitation causes significant reduction of RV volumes. Both, preoperative NT-proBNP level elevation and QRS prolongation indicate patients with poorer outcome regarding RV function and volumes.

How does the tubular embryonic heart work? Looking for the physical mechanism generating unidirectional blood flow in the valveless embryonic heart tube.

The heart is the first organ to function in vertebrate embryos. The human heart, for example, starts beating around the 21st embryonic day. During the initial phase of its pumping action, the embryonic heart is seen as a pulsating blood vessel that is built up by (1) an inner endothelial tube lacking valves, (2) a middle layer of extracellular matrix, and (3) an outer myocardial tube. Despite the absence of valves, this tubular heart generates unidirectional blood flow. This fact poses the question how it works. Visual examination of the pulsating embryonic heart tube shows that its pumping action is characterized by traveling mechanical waves sweeping from its venous to its arterial end. These traveling waves were traditionally described as myocardial peristaltic waves. It has, therefore, been speculated that the tubular embryonic heart works as a technical peristaltic pump. Recent hemodynamic data from living embryos, however, have shown that the pumping function of the embryonic heart tube differs in several respects from that of a technical peristaltic pump. Some of these data suggest that embryonic heart tubes work as valveless "Liebau pumps." In the present study, a review is given on the evolution of the two above-mentioned theories of early cardiac pumping mechanics. We discuss pros and cons for both of these theories. We show that the tubular embryonic heart works neither as a technical peristaltic pump nor as a classic Liebau pump. The question regarding how the embryonic heart tube works still awaits an answer.

Analysis of particulate contaminations of infusion solutions in a pediatric intensive care unit.

PURPOSE: To examine the physical properties and chemical composition of particles captured by in-line microfilters in critically ill children, and to investigate the inflammatory and cytotoxic effects of particles on endothelial cells (HUVEC) and macrophages in vitro. METHODS: Prospective, observational study of microfilters following their use in the pediatric intensive care unit. In vitro model utilizing cytokine assays to investigate the effects of particles on human endothelial cells and murine macrophages. RESULTS: Twenty filter membranes from nine patients and five controls were examined by electron microscopy (EM) and energy dispersion spectroscopy (EDX). The average number of particles found on the surface of the used membranes was 550 cm(2). EDX analysis confirmed silicon as a major particle constituent. Half of the filter membranes showed conglomerates containing an unaccountable number of smaller particles. In vitro, glass particles were used to mimic the high silicon content particles. HUVEC and murine macrophages were exposed to different contents of particles, and cytokine levels were assayed to assess their immune response. Levels of interleukin-1beta, interleukin-6, interleukin-8, and tumor necrosis factor alpha were suppressed. CONCLUSIONS: Particle contamination of infusion solutions exists despite a stringent infusion regiment. The number and composition of particles depends on the complexity of the applied admixtures. Beyond possible physical effects, the suppression of macrophage and endothelial cell cytokine secretion in vitro suggests that microparticle infusion in vivo may have immune-modulating effects. Further clinical trials are necessary to determine whether particle retention by in-line filtration has an influence on the outcome of intensive care patients.

Intravenous luteinizing hormone-releasing hormone has no effect on serum N-terminal pro-brain natriuretic peptide in children and adolescents.

BACKGROUND: Little is known about the acute effects of i.v. luteinizing hormone-releasing hormone (LHRH) on the heart function, therefore the aim of the present study was to measure N-terminal pro-brain natriuretic peptide (N-BNP) in children, who underwent a diagnostic work up for short stature or delayed puberty. METHODS: N-BNP was measured in 52 children before and after administration of LHRH. Serum N-BNP obtained from 255 healthy children and adolescents (aged birth-18.3 years) served as a reference. RESULTS: There was no significant difference between baseline N-BNP of children who underwent the LHRH diagnostic test and their healthy peers. There was no significant serum N-BNP level change before or after administration of LHRH (59 +/- 36 pg/mL vs 58 +/- 34 pg/mL). N-BNP fell from 399 +/- 425 pg/mL in newborns and reached 44 +/- 36 pg/mL in children aged 12-18 years. CONCLUSION: Short stature or delayed puberty had no effect on heart function determined by serum N-BNP; i.v. LHRH does not acutely influence the level of serum N-BNP.

Chances of employment in women and men after surgery of congenital heart disease: comparisons between patients and the general population.

OBJECTIVE: It was examined whether women and men (17-45 years) with operated congenital heart disease differ with respect to chances of employment. Patients were compared with the general population. DESIGN: Patients (n = 314) were classified by type of surgery (curative, reparative, palliative) as indicator of initial severity of disease. The second classification was performed according to a system proposed by the New York Heart Association in order to take reported impairments into account. Controls (n = 1165) consisted of a 10% random sample drawn from the German Socio-Economic Panel. RESULTS: Chances of full-time employment decreased as disease severity increased. Chances of part-time and minor employment were higher in patients than among controls. These general effects were because of male patients, while the employment patterns of women did not differ from the control group. Independent of patient status, women were more likely to have lower rates of full-time employment, and the rates of part-time and minor employment were higher. CONCLUSION: Long-term adaptation to impairments as a result of congenital heart disease differs between women and men with respect to employment status. While female patients do not differ from the general population, males may lower their engagement in paid work.

QRS duration in Fontan circulation in adults: a predictor of aerobic capacity.

BACKGROUND: The univentricular circulation after a Fontan procedure is characterized by an abnormal cardiorespiratory response being attributable to an inability to increase stroke volume during exercise. In congenital heart disease a broad QRS complex has been related to increased intracardiac volume and mass being associated with poor ventricular function and prognosis. OBJECTIVES: This study investigated the relation between the width of the QRS complex and parameters of cardiorespiratory response in adult patients after a Fontan procedure. METHODS: Clinical data and parameters of cardiorespiratory function of 56 patients (15 women, 41 men, mean age 23.7+/-6.4 years, mean age at operation 10.0+/-7.5 years) were related to the width of the QRS complex. RESULTS: In the whole group the mean QRS duration was 115+/-23 ms. A QRS complex >or= 120 ms was present in 23 patients. These patients were characterized by significantly older age at operation (13.0+/-9.3 versus 7.9+/-5.1; p<0.05). Compared to individuals with smaller QRS complexes they showed a decreased oxygen uptake (PeakVO(2): 21.6+/-5.2 versus 27.7+/-6.6 ml/kg/min; p<0.001), work rate (1.6+/-0.5 versus 2.0+/-0.5 W/kg, p<0.05), maximum blood pressure (p<0.001) and increase in blood pressure (p<0.05). Univariate analysis showed a significant correlation between PeakVO(2) and several other parameters of cardiorespiratory exercise testing (work rate,O(2)-pulse, increase in heart rate and blood pressure, maximum heart rate and blood pressure), maximum enddiastolic diameter of the systemic ventricle, age at operation. Multivariate regression analysis identified QRS duration as the only independent predictor of PeakVO(2) (p=0.05). CONCLUSION: In a Fontan circulation a broad QRS complex is a negative predictor of cardiorespiratory function. Early Fontan operation may be beneficial in terms of exercise capacity.