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Introduction Sudden cardiac death in a young athlete is the leading cause of mortality in athletes during sport. Specific knowledge about cardiac adaptations are necessary for a better understanding of the underlying causes of such events. Methods A retrospective analysis of the electrocardiogram and echocardiographic data obtained during the yearly medical examination of the entire German junior national climbing team was undertaken. First, data from 1 examination were used. In a second step, data from 2 examinations spaced 2 y apart were analyzed for a selected subgroup to gain more knowledge about adaptations to climbing. The data from the subgroup were compared to an age- and sex-matched control group of Nordic skiers from the German junior national Nordic skiing team. Results Forty-seven young climbers (20 girls, 27 boys) were examined once. There were no pathological findings in the electrocardiogram or echocardiography. The left ventricular (LV) measurements fell between those for athletes and nonathletes. Eight boys and 6 girls from this group were tested twice over a timeframe of 27.5 mo. All LV measurements increased over time. After 2 y, the measurements from the climbers were comparable to those of the Nordic skiers. Conclusions Hypertrophic cardiomyopathy (hypertrophy of the LV) is the leading cause of sudden cardiac death in athletes. An increase in LV dimensions was observed in the young climbers in this study. LV dimensions being comparable to high-level Nordic skiers after 2 y in the national team imply structural changes over time in this cohort.

Purpose: Rare genetic variants in KDR, encoding the vascular endothelial growth factor receptor 2 (VEGFR2), have been reported in patients with tetralogy of Fallot (TOF). However, their role in disease causality and pathogenesis remains unclear. Methods: We conducted exome sequencing in a familial case of TOF and large-scale genetic studies, including burden testing, in >1,500 patients with TOF. We studied gene-targeted mice and conducted cell-based assays to explore the role of KDR genetic variation in the etiology of TOF. Results: Exome sequencing in a family with two siblings affected by TOF revealed biallelic missense variants in KDR. Studies in knock-in mice and in HEK 293T cells identified embryonic lethality for one variant when occurring in the homozygous state, and a significantly reduced VEGFR2 phosphorylation for both variants. Rare variant burden analysis conducted in a set of 1,569 patients of European descent with TOF identified a 46-fold enrichment of protein-truncating variants (PTVs) in TOF cases compared to controls (P = 7 × 10-11). Conclusion: Rare KDR variants, in particular PTVs, strongly associate with TOF, likely in the setting of different inheritance patterns. Supported by genetic and in vivo and in vitro functional analysis, we propose loss-of-function of VEGFR2 as one of the mechanisms involved in the pathogenesis of TOF.

Background Decellularization of pulmonary valve substitutes is believed to eliminate immunogenicity and improve conduit durability. This study focused on a detailed histopathological and immunohistochemical analysis of explanted Matrix P plus valves, following their early obstruction in pediatric patients. Methods Occurrence of fibrosis, scar formation, neovascularization, and inflammatory infiltrates were determined in longitudinal sections of four valve specimens explanted after 12–15 months. Valves were immunohistochemically analyzed for presence of different subtypes of inflammatory cells. The expression of smooth muscle actin and connective tissue growth factor was determined. Results We observed a foreign body-type reaction accompanied by severe fibrosis and massive neointima formation around decellularized porcine valve wall, whereas the equine pericardial patch remained separated from porcine layer and acellular. Re-cellularization of decellularized matrix was low, and neovascularization was observed only in the neointima and scar tissue. Inflammatory infiltrates, composed mainly of T cells, B cells, and plasma cells, as well as the presence of dendritic cells, macrophages, and mast cells were detected in the tissue surrounding the porcine matrix. In the fibrous tissue, overexpression of connective tissue growth factor was observed. The leaflets remained functional, with normal endothelialization and no degenerative changes. Control pre-implant samples of Matrix P plus valve revealed incomplete decellularization of porcine matrix, which may have contributed to increased immunogenicity of these conduits. Conclusions Early obstruction of decellularized Matrix P plus valve is associated with massive inflammatory reaction and exaggerated fibrotic scaring around porcine conduit wall. Detailed studies will be necessary to determine factors that contribute to remnant immunogenicity of decellularized grafts.

Pulmonary hypertension (PH) is a chronic progressive disease with mean pulmonary arterial pressure (MPAP) >25 mmHg, progressing to right ventricular dysfunction, heart failure and death. Medical management remains challenging with unpredictable outcomes. The efficacy of an interatrial shunt in

Based on myocardial Doppler echocardiography, regional strain (S) and strain rate (SR) can be evaluated as regional parameters of ventricular function. The use of these techniques in clinical pediatric cardiology remains a challenge. This study establishes reference values for S and SR in both systole and diastole in healthy children over a large age range and evaluates the potential relationships of demographic and echocardiographic parameters on S and SR, and, in particular, assesses the clinical effect of heart rate on S and SR in healthy children. It is shown that heart rate changes in children during growth have an important impact on both systolic and diastolic myocardial S and late diastolic SR. Therefore, to evaluate regional myocardial function in children, heart rate at rest should be considered an important factor.

Background . Due to the limited availability of homografts, different alternatives are used for replacement of the pulmonary valve. This study investigates the value of porcine stentless pulmonary xenografts in pediatric cardiac patients. Methods . Twenty-three pediatric xenograft (size 10 to 21 mm) recipients were compared with 23 homograft (size 9 to 21 mm) recipients. Results . Hospital mortality was 2 of 23 patients in the xenograft group and 3 of 23 in the homograft group (NS). Six out of 20 xenografts and 1 of 19 homografts were stenotic after 1 year ( p = 0.011). Xenograft stenoses were mainly located at the distal anastomosis, while the leaflets were preserved. Homografts showed valvular stenoses and wall calcification. The 1 year freedom from reoperation was 77% in the xenograft and 93% in homograft recipients (NS), and from transcatheter intervention 84% and 100% ( p = 0.004), respectively. Transcatheter intervention in 7 xenograft patients and 1 homograft recipient improved stenosis gradients from 65 to 40 mm Hg (mean) in 6 out of 8 patients. Explanted xenografts showed a loss of elastic membranes and proliferating connective tissue scares coated with activated endothelium. Conclusions . Xenografts demonstrated a higher incidence of supravalvular obstructions, which were possibly due to unfavorable hemodynamics at the distal anastomosis. Histological findings additionally indicated a pronounced immunological response. Interventional angioplasty lowered the rate of reoperation. Thus, the use of xenografts in children can be accepted as a second choice when a homograft is unavailable.

We studied perioperative renal damage in 22 patients with long-standing cyanotic congenital heart disease. Backround: Postoperative acute renal failure is a major complication of cardiac surgery associated with poor prognosis. Our study was designed to identify risk factors for renal failure in patients with cyanotic congenital heart disease. Patients: 22 cyanotic patients with a oxygen saturation of 82% (38–92%), age 14 years (5–42 years) and six controls with atrial septal defect, age 37 years (28–66 years) were investigated with repeated urinary analyses. Results: Before operation, six of 22 of the cyanotic patients had albuminuria. Postoperatively three patients developed acute renal failure including glomerular and tubular damage. Urinary albumin analysis >1000 mg g −1 creatinine after 24 h and N -acteyl-β-d-glucosaminidase analysis >100 U g −1 creatinine after 48 h predicted dialysis requirement. In noncyanotic controls only one preoperative and none of the postoperative analyses were pathological. Conclusions: Patients with cyanotic congenital heart disease are at risk for acute renal failure, which can be prognosed by urine analysis already 24 h after surgery. Cyanotic glomerulopathy should be known before surgery. To lower the risk, cardiopulmonary bypass time should be kept as short as possible and adequate hydration should be maintained in combination with extended diuretic therapy.

Background . The role of peritoneal dialysis (PD) in the management of infants after heart operation is under discussion. The aim of this study was to investigate the effect of PD on fluid balance and outcome. Methods . Twenty-seven (33%) of 81 consecutive infants who underwent heart operation required PD. In 22 patients (81%), PD was started prophylactically at the end of the operation. We recorded hemodynamic data and fluid balance. Patients experiencing acute renal failure (ARF) were compared with the remaining infants. Results . Eleven of 81 patients (14%) experienced ARF; 3 of them died (4% of all patients undergoing operation, 27% of those with ARF). Complications of PD, present in 33%, were transitory and of minor significance. Patients with ARF had decreased cardiac function compared with those without ARF but similar fluid balance. Conclusions . Peritoneal dialysis is an effective and safe method for the treatment of ARF in infants after open heart operation. As PD is helpful in modulating postoperative fluid balance, prophylactic use of PD can be recommended for selected patients who are at risk for low cardiac output syndrome.

An 8-year-old (35 kg) boy presented with progressive right ventricular outflow tract enlargement (28 mm) and progressive tricuspid regurgitation after transannular repair of tetralogy of Fallot and was scheduled for pulmonary valve replacement. To spare reoperation on full sternotomy, a transverse mini-thoracotomy through the third intercostal space was used to implant an injectable 29-mm stented porcine valve directly through an incision of the pulmonary artery bifurcation. The procedure was performed while rapid ventricular pacing and right ventricular unload by a short running femorally implanted cardiopulmonary bypass. The stented valve was fixed with three single sutures to avoid embolization. The interventional result was well with full competence of the valve. The boy was discharged at day 4 after the procedure.

Late-diastolic forward flow is a well-described phenomenon detectable by Doppler echocardiography in the pulmonary trunk. It is supported by a restrictive right ventricular diastolic function and by a low end-diastolic pulmonary artery pressure. A similar phenomenon for the left ventricle and the aorta has not been described. We report a case of a preterm infant with aortic stenosis and endocardial fibroelastosis, who underwent balloon valvuloplasty. Restrictive left ventricular diastolic filling led to high left atrial pressure (27 mm Hg) and a very pathologic ratio of early-to-late peak velocities (2.6) for an infant of 29 weeks' gestation. In combination with a low diastolic aortic pressure (24 mm Hg) caused by moderate aortic regurgitation after intervention, a late-diastolic forward flow was detectable in the aorta during left atrial contraction with pulsed Doppler echocardiography. (J Am Soc Echocardiogr 2000;13:866-8.)

B-type natriuretic peptide (BNP) was measured in 43 children and adolescents with high-grade second degree or complete atrioventricular conduction block. BNP plasma level was significantly higher (p

The observation of the occurence of transient Thus, preoperative glomerular abnormalities might microalbuminuria in a pediatric population after open influence the individual risk for bypass induced heart surgery provided by Millar and South adds to albuminuria in patients with chronic cyanotic heart the conclusion that investigating microalbuminuria is disease. a useful and important parameter in postoperative monitoring. With our data upraised in a group of patients with chronic cyanosis [1] it is not advisable References to comment on the relationship between bypass induced inflammation and increased endothelial per[1] Dittrich S et al. Renal function after cardiopulmonary bypass surgery in cyanotic congenital heart disease. Int J Cardiol meability. However, the assumption of preoperative 2000;73(2):173–9. existent glomerular abnormalities in cyanotic [2] Perloff JK, Latta H, Barsotti P. Pathogenesis of the glomerular congenital heart disease has recently been abnormality in cyanotic congenital heart disease. Am J Cardiol 2000;86(11):1198–204. strengthened by Perloff and colleagues [2] who described a vascular and a nonvascular pathogenesis.