Perioperative diagnosis and impact of acquired von Willebrand syndrome in infants with congenital heart disease.

Acquired von Willebrand syndrome (aVWS) has been reported in patients with congenital heart diseases associated with shear stress caused by significant blood flow gradients. Its etiology and impact on intraoperative bleeding during pediatric cardiac surgery have not been systematically studied. This single-center, prospective, observational study investigated appropriate diagnostic tools of aVWS compared with multimer analysis as diagnostic criterion standard and aimed to clarify the role of aVWS in intraoperative hemorrhage. A total of 65 newborns and infants aged 0 to 12 months scheduled for cardiac surgery at our tertiary referral center from March 2018 to July 2019 were included in the analysis. The glycoprotein Ib M assay (GPIbM)/von Willebrand factor antigen (VWF:Ag) ratio provided the best predictability of aVWS (area under the receiver operating characteristic curve [AUC], 0.81 [95% CI, 0.75-0.86]), followed by VWF collagen binding assay/VWF:Ag ratio (AUC, 0.70 [0.63-0.77]) and peak systolic echocardiographic gradients (AUC, 0.69 [0.62-0.76]). A cutoff value of 0.83 was proposed for the GPIbM/VWF:Ag ratio. Intraoperative high-molecular-weight multimer ratios were inversely correlated with cardiopulmonary bypass (CPB) time (r = -0.57) and aortic cross-clamp time (r = -0.54). Patients with intraoperative aVWS received significantly more fresh frozen plasma (P = .016) and fibrinogen concentrate (P = .011) than those without. The amounts of other administered blood components and chest closure times did not differ significantly. CPB appears to trigger aVWS in pediatric cardiac surgery. The GPIbM/VWF:Ag ratio is a reliable test that can be included in routine intraoperative laboratory workup. Our data provide the basis for further studies in larger patient cohorts to achieve definitive clarification of the effects of aVWS and its potential treatment on intraoperative bleeding.

Clinical course and follow-up of pediatric patients with COVID-19 vaccine-associated myocarditis compared to non-vaccine-associated myocarditis within the prospective multicenter registry-"MYKKE".

BACKGROUND: Since the onset of widespread COVID-19 vaccination, increased incidence of COVID-19 vaccine-associated myocarditis (VA-myocarditis) has been noted, particularly in male adolescents. METHODS: Patients <18 years with suspected myocarditis following COVID-19 vaccination within 21 days were enrolled in the PedMYCVAC cohort, a substudy within the prospective multicenter registry for pediatric myocarditis "MYKKE." Clinical data at initial admission, 3- and 9-months follow-up were monitored and compared to pediatric patients with confirmed non-vaccine-associated myocarditis (NVA-myocarditis) adjusting for various baseline characteristics. RESULTS: From July 2021 to December 2022, 56 patients with VA-myocarditis across 15 centers were enrolled (median age 16.3 years, 91% male). Initially, 11 patients (20%) had mildly reduced left ventricular ejection fraction (LVEF; 45%-54%). No incidents of severe heart failure, transplantation or death were observed. Of 49 patients at 3-months follow-up (median (IQR) 94 (63-118) days), residual symptoms were registered in 14 patients (29%), most commonly atypical intermittent chest pain and fatigue. Diagnostic abnormalities remained in 23 patients (47%). Of 21 patients at 9-months follow-up (259 (218-319) days), all were free of symptoms and diagnostic abnormalities remained in 9 patients (43%). These residuals were mostly residual late gadolinium enhancement in magnetic resonance imaging. Patients with NVA-myocarditis (n=108) more often had symptoms of heart failure (P = .003), arrhythmias (P = .031), left ventricular dilatation (P = .045), lower LVEF (P < .001) and major cardiac adverse events (P = .102). CONCLUSIONS: Course of COVID-19 vaccine-associated myocarditis in pediatric patients seems to be mild and differs from non-vaccine-associated myocarditis. Due to a considerable number of residual symptoms and diagnostic abnormalities at follow-up, further studies are needed to define its long-term implications.

Isolated cytokine-enriched pericardial effusion: A likely key feature for Aymé-Gripp syndrome.

Aymé-Gripp syndrome is a multisystemic disorder caused by a heterozygous variation in the MAF gene (OMIM*177075). Key features are congenital cataracts, sensorineural hearing loss, and a characteristic facial appearance. In a proportion of individuals, pericardial effusion or pericarditis has been reported as part of the phenotypic spectrum. In the present case, a large persistent cytokine-enriched pericardial effusion was the main pre- and postnatal symptom that led to the clinical and later molecular diagnosis of Aymé-Gripp syndrome. In the postnatal course, the typical Aymé-Gripp syndrome-associated features bilateral cataracts and hearing loss were diagnosed. We propose that activating dominant variants in the cytokine-modulating transcription factor c-MAF causes cytokine-enriched pericardial effusions possibly representing a key feature of Aymé-Gripp syndrome.

Cardiovascular magnetic resonance in children with suspected myocarditis: current practice and applicability of adult protocols.

BACKGROUND: Cardiovascular magnetic resonance serves as a useful tool in diagnosing myocarditis. Current adult protocols are yet to be validated for children; thus, it remains unclear if the methods used can be applied with sufficient image quality in children. This study assesses the use of cardiovascular magnetic resonance in children with suspected myocarditis. METHODS: Image data from clinical cardiovascular magnetic resonance studies performed in children enrolled in Mykke between June 2014 and April 2019 were collected and analysed. The quality of the data sets was evaluated using a four-point quality scale (4: excellent, 3: good, 2: moderate, 1: non-diagnostic). RESULTS: A total of 102 patients from 9 centres were included with a median age (interquartile range) of 15.4(10.7-16.6) years, 137 cardiovascular magnetic resonance studies were analysed. Diagnostic image quality was found in 95%. Examination protocols were consistent with the original Lake Louise criteria in 58% and with the revised criteria in 35%. Older patients presented with better image quality, with the best picture quality in the oldest age group (13-18 years). Sedation showed a negative impact on image quality in late gadolinium enhancement and oedema sequences. No such correlation was seen in cardiac function assessment sequences. In contrast to initial scans, in follow-up examinations, the use of parametric mapping increased while late gadolinium enhancement and oedema sequences decreased. CONCLUSION: Cardiovascular magnetic resonance protocols for the assessment of adult myocarditis can be applied to children without significant constraints in image quality. Given the lack of specific recommendations for children, cardiovascular magnetic resonance protocols should follow recent recommendations for adult cardiovascular magnetic resonance.

A Comprehensive Functional Analysis in Patients after Atrial Switch Surgery.

BACKGROUND: Long-term course after atrial switch operation is determined by increasing right ventricular (RV) insufficiency. The aim of our study was to investigate subtle functional parameters by invasive measurements with conductance technique and noninvasive examinations with cardiac magnetic resonance imaging (CMR). METHODS: We used invasive (pressure-volume loops under baseline conditions and dobutamine) and noninvasive techniques (CMR with feature tracking [FT] method) to evaluate RV function. All patients had cardiopulmonary exercise testing (CPET). RESULTS: From 2011 to 2013, 16 patients aged 28.2 ± 7.3 (22-50) years after atrial switch surgery (87.5% Senning and 12.5% Mustard) were enrolled in this prospective study. All patients were in New York Heart Association (NYHA) class I to II and presented mean peak oxygen consumption of 30.1 ± 5.7 (22.7-45.5) mL/kg/min. CMR-derived end-diastolic volume was 110 ± 22 (78-156) mL/m2 and RV ejection fraction 41 ± 8% (25-52%). CMR-FT revealed lower global systolic longitudinal, radial, and circumferential strain for the systemic RV compared with the subpulmonary left ventricle. End-systolic elastance (Ees) was overall reduced (compared with data from the literature) and showed significant increase under dobutamine (0.80 ± 0.44 to 1.89 ± 0.72 mm Hg/mL, p ≤ 0.001), whereas end-diastolic elastance (Eed) was not significantly influenced (0.11 ± 0.70 to 0.13 ± 0.15 mm Hg/mL, p = 0.454). We found no relevant relationship between load-independent conductance indices and strain or CPET parameters. Conductance analysis revealed significant mechanical dyssynchrony, higher during diastole (mean 30 ± 4% baseline, 24 ± 6% dobutamine) than during systole (mean 17 ± 6% baseline, 19 ± 7% dobutamine). CONCLUSIONS: Functional assessment of a deteriorating systemic RV remains demanding. Conductance indices as well as the CMR-derived strain parameters showed overall reduced values, but a significant relationship was not present (including CPET). Our conductance analysis revealed intraventricular and predominantly diastolic RV dyssynchrony.

Stent-retriever thrombectomy in the treatment of infants with acute thrombosis of the superior vena cava and innominate vein.

OBJECTIVES: To describe the efficacy and safety of stent-retriever thrombectomy in infants with thrombosis of the superior vena cava (SVC) and innominate vein. BACKGROUND: Thrombosis of the SVC and of the innominate vein is a potentially life threatening complication in infants during intensive care treatment following major surgical procedures. To avoid reoperations, we evaluated interventional revascularization by stent-retriever thrombectomy. METHODS: From 2015 to 2017, five infants were diagnosed with acute thrombosis of the SVC and innominate vein following major cardiac or pediatric surgery. Using a femoral venous access and 4 or 5 French guiding catheters stent-retriever systems (4/20 mm or 6/30 mm) were placed into the thrombus and retrieved under suction. We aimed to revascularize not only the SVC but also the innominate, jugular, and subclavian veins. RESULTS: Following repeated stent retrieving manoeuvers, we were able to reestablish flow in the major veins of all patients. Due to significant residual thrombotic material, we decided to perform additional balloon dilatation of the SVC and innominate vein in 3/5 patients. There were no complications related to the procedure and none of our patients required blood transfusion. Following the intervention, the patients received treatment with low-molecular-weight heparin. Interventional treatment achieved persistent patency of the SVC and innominate vein in all patients. CONCLUSION: Stent-retriever thrombectomy is a safe and effective method for interventional treatment of acute thrombosis of the central veins in infants. Due to the large amount of thrombotic material, it is frequently required to combine this method with balloon compression of residual thrombotic material.

Severe heart failure and the need for mechanical circulatory support and heart transplantation in pediatric patients with myocarditis: Results from the prospective multicenter registry "MYKKE".

Myocarditis represents an important cause for acute heart failure. MYKKE, a prospective multicenter registry of pediatric patients with myocarditis, aims to gain knowledge on courses, diagnostics, and therapy of pediatric myocarditis. The role of mechanical circulatory support (MCS) in children with severe heart failure and myocarditis is unclear. The aim of this study was to determine characteristics and outcome of patients with severe heart failure requiring MCS and/or heart transplantation. The MYKKE cohort between September 2013 and 2016 was analyzed. A total of 195 patients were prospectively enrolled by 17 German hospitals. Twenty-eight patients (14%) received MCS (median 1.5 years), more frequently in the youngest age group (0-2 years) than in the older groups (P < 0.001; 2-12 and 13-18 years). In the MCS group, 50% received a VAD, 36% ECMO, and 14% both, with a survival rate of 79%. The weaning rate was 43% (12/28). Nine (32%) patients were transplanted, one had ongoing support, and six (21%) died. Histology was positive for myocarditis in 63% of the MCS group. Patients within the whole cohort with age <2 years and/or ejection fraction <30% had a significantly worse survival with high risk for MCS, transplantation, and death (P < 0.001). Myocarditis represents a life-threatening disease with an overall mortality of 4.6% in this cohort. The fulminant form more often affected the youngest, leading to significantly higher rate of MCS, transplantation, and mortality. MCS represents an important and life-saving therapeutic option in children with myocarditis with a weaning rate of 43%.

Comparative Noninvasive Measurement of Cardiac Output Based on the Inert Gas Rebreathing Method (Innocor®) and MRI in Patients with Univentricular Hearts.

There are many complex cardiac malformations that are characterized by a functionally univentricular physiology. Staged surgical repair according to the Fontan principle separates the systemic and pulmonary circulations by connecting the systemic venous return to the pulmonary arteries. However, long-term follow-up studies demonstrate a gradual deterioration of cardiac function, particularly from the second or third decade. Noninvasive evaluation of the cardiac function is, therefore, important in the follow-up of these patients. The cardiac index (CI) is a reliable hemodynamic parameter and represents an important marker of cardiac function. We compared CI values determined by cardiac MRI (CMRI) with values obtained by noninvasive inert gas rebreathing (IGR; Innocor® system). Sixteen patients (age range: 7.2-32.7 years) with functionally univentricular hearts (UVH) following total cavopulmonary connection (TCPC) were compared with 12 healthy subjects (age range: 8.5-18.6 years). The standard treadmill protocol of the German Society of Pediatric Cardiology was used for exercise testing. CI was determined at rest and at two standardized submaximal exercise levels. In all subjects, CI increased under exercise conditions, but the values were significantly lower in patients with UVH. There was no significant difference between patients with UVH and predominantly right- or left-ventricular morphology. In comparison with CMRI measurements, the CI values obtained by the IGR method tended to be lower, with a mean difference of 1.02 l/min/m2. Noninvasive measurement of CI with the IGR method is feasible at rest and during exercise, and appears to be suited for routine determination of CI in patients with UVH following TCPC.

Toward evidence-based diagnosis of myocarditis in children and adolescents: Rationale, design, and first baseline data of MYKKE, a multicenter registry and study platform.

The aim of this registry is to provide data on age-related clinical features of suspected myocarditis and to create a study platform allowing for deriving diagnostic criteria and, at a later stage, testing therapeutic interventions in patients with myocarditis. STUDY DESIGN AND RESULTS: After an initial 6-month pilot phase, MYKKE was opened in June 2014 as a prospective multicenter registry for patients from pediatric heart centers, university hospitals, and community hospitals with pediatric cardiology wards in Germany. Inclusion criteria consisted of age<18 years and hospitalization for suspected myocarditis as leading diagnosis at the discretion of the treating physician. By December 31, 2015, fifteen centers across Germany were actively participating and had enrolled 149 patients. Baseline data reveal 2 age peaks (<2 years, >12 years), show higher proportions of males, and document a high prevalence of severe disease courses in pediatric patients with suspected myocarditis. Severe clinical courses and early adverse events were more prevalent in younger patients and were related to severely impaired leftventricular ejection fraction at initial presentation. SUMMARY: MYKKE represents a multicenter registry and research platform for children and adolescents with suspected myocarditis that achieve steady recruitment and generate a wide range of real-world data on clinical course, diagnostic workup, and treatment of this group of patients. The baseline data reveal the presence of 2 age peaks and provide important insights into the severity of disease in children with suspected myocarditis. In the future, MYKKE might facilitate interventional substudies by providing an established collaborating network using common diagnostic approaches.

Esophageal perforation caused by an AMPLATZERTM vascular plug 4 occlusion device.

The AMPLATZERTM Vascular Plug 4 (AVP4) is a self-expandable, replaceable occluder made of Nitinol wire mesh, which allows the safe and effective interventional occlusion of medium size vessels. This report describes an infant diagnosed with pulmonary atresia, ventricular septal defect, and multifocal collateral lung perfusion through four major aortopulmonary collateral arteries (MAPCAs). A central aorto-pulmonary shunt was performed at 4 months of age. Because of postoperative pulmonary hyperperfusion, one of the MAPCAs was closed interventionally using a 5 mm AVP4. This MAPCA originated from the descending aorta (DAO) near the fifth thoracic vertebra and ran behind the esophagus to the lower lobe of the right lung. The MAPCA was closed near its origin from the DAO. Four weeks later, the patient presented with severe gastrointestinal bleeding, caused by perforation of the AVP4 into the esophagus. The occluder was extracted surgically, the MAPCA was clipped and the esophageal injury was sutured. To date, there have been no reports describing esophageal perforation due to an AVP4. The perforation in this patient may have been due to implantation of the AVP4 near the aorta in a MAPCA segment located directly in front of the spine and behind the esophagus. Another possible factor may have been the requirement for a gastrointestinal feeding tube. Although the occluder is soft and flexible, the spindle-shaped ends may cause trauma if they are located close to other structures. © 2016 Wiley Periodicals, Inc.

Successful thrombolysis following enoxaparin therapy in two pediatric patients with congenital heart disease presenting with intracardiac and cerebral thrombosis.

Enoxaparin displays fibrinolytic activity through stimulation of endothelial release of tissue plasminogen activator. Moreover, enoxaparin increases the release of tissue factor pathway inhibitor, which inhibits coagulation activity. However, there are only few reports regarding the use of enoxaparin for the treatment of children with thrombosis complicating congenital heart disease. We report the clinical findings from two patients, one child with an A. cerebri media infarction and another with a left ventricular thrombus. In both cases successful thrombolysis was obtained by intravenous administration of enoxaparin. The first patient was a 12-year-old girl with an atrioventricular septal defect, who underwent biventricular repair at the age of 8 months. She presented with right-sided middle cerebral artery infarction. Thrombolysis was contraindicated, because she was beyond the therapeutic window recommended by accepted guidelines. Enoxaparin 2.5 mg/kg/d was administered as a continuous intravenous infusion (CII). The MRI 10 days later revealed a reopened middle cerebral artery and she experienced complete remission of the neurological signs. The second patient was a 16-year-old boy who had tetralogy of Fallot corrected in late infancy. He presented with severe heart failure and a mural thrombus in the left ventricular apex. Enoxaparin was administered and resulted in complete disappearance of the thrombus within a week. According to our experience, CII of enoxaparin was safe and well tolerated without secondary bleeding and resulted in complete dissolution of the thrombi without secondary embolization. Therefore, CII of enoxaparin may be a possible alternative for the treatment of thrombotic complications in children with contraindications against conventional thrombolytic therapy.

Anterosuperior diverticula of the right ventricle: morphological spectrum and long-term outcome of a distinct cardiac anomaly.

Right-ventricular diverticula (RVD), although rare, have particular characteristics. Our study describes the morphology of anterosuperior diverticula of the right ventricle (RV) and patient outcome for this anomaly. Retrospective analysis was performed on all patients with anterosuperior RVD diagnosed in two tertiary referral centres. From January 1982 to December 2012, five patients were diagnosed with anterosuperior RVD (median 4 months). Four patients had perimembranous ventricular septal defects (VSDs) with no clinical symptoms related to RVD. Communication of the RVD with the RV was located either close to the VSD (two patients) or in the anterior free wall of the RV opposite the VSD (two patients). In the remaining patient, the diverticulum was connected with the left ventricle (LV) by a tunnel-like structure originating from the left-ventricular outflow tract; the RVD communicated with the RV by way of a restrictive opening. Four patients underwent surgical repair including patch closure of the VSD (one patient) and patch closure of the VSD through an incision of the RVD followed by plication of the diverticulum or closure of its communication with the RV (three patients). All patients remained asymptomatic during a median follow-up of 14.8 years. Anterosuperior RVD is a specific congenital cardiovascular anomaly frequently associated with additional congenital heart disease. There are significant variations in how the RVD communicates with the RV with each requiring a different surgical repair strategy. According to the experience in our small cohort, the long-term prognosis of patients with anterosuperior RVD appears excellent after surgical correction of associated congenital heart disease.

Transcatheter closure of abnormal vessels and arteriovenous fistulas with the Amplatzer vascular plug 4 in patients with congenital heart disease.

Although vascular plugs allow the interventional closure of medium-sized to large abnormal vessels, their application is limited by the need for long sheaths or large guiding catheters. The authors report their experience with the new Amplatzer vascular plug 4 (AVP 4), a self-expanding spindle-shaped occluder made of Nitinol wire mash, which can be placed through 4-Fr catheters with an internal diameter of 0.038 in. or larger. From October 2009 until June 2012, 14 AVP 4 devices were deployed in 12 patients (ages, 0.3-48.8 years). Nine patients had venovenous or arteriovenous collaterals in functional univentricular hearts. One patient had pulmonary atresia with a ventricular septal defect and major aortopulmonary collateral arteries, and one patient had a pulmonary arteriovenous fistula. One child had a large coronary artery fistula to the right atrium. The authors used AVP 4 devices with diameters of 4-8 mm. In all the patients, the AVP 4 was implanted successfully. No occluder dislocations and no complications related to the procedure occurred. Complete vessel occlusion was achieved in seven cases. In seven additional cases, a residual shunt was present at the end of the procedure while the patients were still fully heparinized. In 2 of 14 vessels, the decision was made to place additional devices to abolish residual shunting. According to the authors' experience, the AVP 4 allows safe and effective occlusion of medium-size and large abnormal vessels. It is also well suited for tortuous high-flow vessels such as coronary or pulmonary arteriovenous fistulas. In case of a suboptimal position, it is possible to reposition the occluder with ease. Further studies are needed to determine whether initial residual shunting in heparinized patients disappears during follow-up care. The AVP 4 represents a valuable new device for the interventional treatment of complex congenital vessel malformations.

Myocarditis and sports in the young: data from a nationwide registry on myocarditis-"MYKKE-Sport".

Background: Myocarditis represents one of the most common causes of Sudden Cardiac Death in children. Myocardial involvement during a viral infection is believed to be higher as a consequence of intensive exertion. Recommendations for return to sports are based on cohort and case studies only. This study aims to investigate the relationship between physical activity and myocarditis in the young. Patient: Every patient in the MYKKE registry fulfilling criteria for suspicion of myocarditis was sent a questionnaire regarding the physical activity before, during and after the onset of myocarditis. Method: This study is a subproject within the MYKKE registry, a multicenter registry for children and adolescents with suspected myocarditis. The observation period for this analysis was 93 months (September 2013-June 2021). Anamnestic, cardiac magnetic resonance images, echocardiography, biopsy and laboratory records from every patient were retrieved from the MYKKE registry database. Results: 58 patients (mean age 14.6 years) were enrolled from 10 centers. Most patients participated in curricular physical activity and 36% in competitive sports before the onset of myocarditis. There was no significant difference of heart function at admission between the physically active and inactive subjects (ejection fraction of 51.8 ± 8.6% for the active group vs. 54.4 ± 7.7% for the inactive group). The recommendations regarding the return to sports varied widely and followed current guidelines in 45%. Most patients did not receive an exercise test before returning to sports. Conclusion: Sports before the onset of myocarditis was not associated with a more severe outcome. There is still a discrepancy between current literature and actual recommendations given by health care providers. The fact that most participants did not receive an exercise test before being cleared for sports represents a serious omission.

Noninvasive cardiac output measurement at rest and during exercise in pediatric patients after interventional or surgical atrial septal defect closure.

In the majority of patients, secundum atrial septal defects (ASDs) are treated interventionally or surgically, before the onset of clinical symptoms, between 3 and 6 years of age. Because right-ventricular dimensions usually normalize after ASD closure, it has been assumed that cardiac function and exercise performance also normalize at long-term follow-up. The aim of our study was to determine cardiac index (CI) at rest and during exercise at medium-term follow-up of children who had undergone surgical or interventional closure of ASD because no such reports have been published thus far. Seventeen patients (age range 8.8-17.3 years) who underwent surgical correction were included together with 17 subjects who received an interventional procedure with Amplatzer and Helex occluders (age range 12.2-17.3 years). The study was performed after a median interval of 8.6 years (range 6.5-11.6) after the procedure. Twelve healthy children of comparable age served as controls. CI measurements were performed based on the inert gas-rebreathing method with the Innocor system. For exercise testing, the standard treadmill protocol of the German Society of Pediatric Cardiology was used. CI, stroke volume (SV), and heart rate (HR) were determined at rest and at two standardized submaximal exercise levels (levels 3 and 6). CI increased in all subjects under exercise conditions. Neither SV nor HR displayed significant differences between the three groups either at rest or under exercise conditions. Although HR increased continuously, no increase of indexed SV occurred beyond level 3. Noninvasive determination of CI at rest and during exercise with the IGR method is feasible in the pediatric age group. At medium-term follow-up, we found no significant differences between patients who underwent surgical or interventional ASD closure compared with normal controls.

Acquired von Willebrand syndrome is common in infants with systemic-to-pulmonary shunts: Retrospective case-series.

Background: Although acquired von Willebrand syndrome (aVWS) has been described in congenital heart disease before, anatomical features leading to aVWS with characteristic reduction or loss of high molecular weight von Willebrand multimers (HMWM) are not well known. This study assesses the prevalence and effects of aVWS in infants with systemic-to-pulmonary shunts (SPS). Methods: This retrospective single-center study analyzes diagnostic data of infants with complex congenital heart defects requiring palliation with SPS. During the study period between 12/15-01/17 fifteen consecutive patients were eligible for analysis. Results of von Willebrand factor antigen (VWF:Ag), collagen binding activity (VWF:CB) and von Willebrand factor multimer analysis were included. Results: In all 15 patients with SPS an aVWS could be found. Blood samples were collected between 5 and 257 days after shunt implantation (median 64 days). None of the patients demonstrated increased bleeding in everyday life. However, 6 out of 15 patients (40%) showed postoperative bleeding complications after SPS implantation. Following shunt excision multimeric pattern normalized in 8 of 10 (80%) patients studied. Conclusions: This study shows that in patients undergoing SPS implantation aVWS might emerge. Pathogenesis can be explained by shear stress resulting from turbulent flow within the shunt. Knowledge of aVWS existence is important for the consideration of replacement therapy with von Willebrand factor containing products and antifibrinolytic treatment in bleeding situations. Implementation of methods for rapid aVWS detection is required to achieve differentiated hemostatic therapy and reduce the risk of complications caused by empiric replacement therapy.

Clinical characteristics and outcome of biopsy-proven myocarditis in children - Results of the German prospective multicentre registry "MYKKE".

BACKGROUND: Heart failure (HF) due to myocarditis might not respond in the same way to standard therapy as HF due to other aetiologies. The aim of this study was to investigate the value of endomyocardial biopsies (EMB) for clinical decision-making and its relation to the outcome of paediatric patients with myocarditis. METHODS: Clinical and EMB data of children with myocarditis collected for the MYKKE-registry between 2013 and 2020 from 23 centres were analysed. EMB studies included histology, immunohistology, and molecular pathology. The occurrence of major adverse cardiac events (MACE) including mechanical circulatory support (MCS), heart transplantation, and/or death was defined as a combined endpoint. RESULTS: Myocarditis was diagnosed in 209/260 patients: 64% healing/chronic lymphocytic myocarditis, 23% acute lymphocytic myocarditis (AM), 14% healed myocarditis, no giant cell myocarditis. The median age was 12.8 (1.4-15.9) years. Time from symptom-onset to EMB was 11.0 (4.0-29.0) days. Children with AM and high amounts of mononuclear cell infiltrates were significantly younger with signs of HF compared to those with healing/chronic or healed myocarditis. Myocardial viral DNA/RNA detection had no significant effect on outcome. The worst event-free survival was seen in patients with healing/chronic myocarditis (24%), followed by acute (31%) and healed myocarditis (58%, p = 0.294). A weaning rate of 64% from MCS was found in AM. CONCLUSIONS: EMB provides important information on the type and stage of myocardial inflammation and supports further decision-making. Children with fulminant clinical presentation, high amounts of mononuclear cell infiltrates or healing/chronic inflammation and young age have the highest risk for MACE.

Fulminant Rhizomucor pusillus mucormycosis during anti-leukemic treatment with blinatumomab in a child: A case report and review of the literature.

This is the first published case report of a child with acute lymphatic leukemia developing a fatal mucormycosis during blinatumomab treatment. The patient showed multiple, systemic thromboembolic lesions with ischemia, bleeding and infarction in almost all organs. The child succumbed to increased brain pressure resulting in cerebral herniation. This case particularly illustrates the fulminant progression and huge challenges of diagnosing and treating mucormycosis in children with hemato-oncological diseases during treatment with targeted therapeutic antibodies (blinatumomab).

Noninvasive cardiac output determination for children by the inert gas-rebreathing method.

Standard methods for determination of cardiac output (CO) are either invasive or technically demanding. Measurement of CO by the inert gas-rebreathing (IGR) method, applied successfully in adults, uses a low-concentration mixture of an inert and a blood-soluble gas, respectively. This study tested the feasibility of this method for determining CO during exercise for pediatric patients with complete congenital atrioventricular block (CCAVB) stimulated with a VVI pacemaker. In this study, 5 CCAVB patients (age 9.2-17.4 years) were compared with 10 healthy age-matched boys and girls. Testing was performed with the Innocor system. The patients were instructed to breathe the test gas from a closed system. Pulmonary blood flow was calculated according to the washout of the soluble gas component. During standardized treadmill testing, CO was determined at three defined levels. The CO measurements were successful for all the study participants. The patients reached a lower peak CO than the control subjects (5.9 l/min/m(2) vs 7.3 [boys] and 7.2 [girls]). The stroke volume increase under exercise also was reduced in the patients compared with the control subjects. The feasibility of the IGR method for exercise CO testing in children was documented. Application of the IGR method for children requires careful instruction of the patients and appears restricted to subjects older than 8 years. The method offers new insights into mechanisms of cardiovascular adaptation in children with congenital heart disease.

Ventriculoatrial malalignment in atrioventricular septal defect resulting in uniatrial biventricular connection: surgical options.

BACKGROUND: Uniatrial biventricular connection (UBC) is a rare cardiovascular anomaly characterized by absence of one atrioventricular connection and drainage of the other atrium via a solitary atrioventricular valve into both ventricles. The absent atrioventricular connection may affect either the left or right atrium. Because of the absence of one atrioventricular connection hearts with UBC have been classified among functionally univentricular hearts requiring palliative treatment according to the Fontan principle. AIMS/OBJECTIVE: We report two further patients with UBC. In one of these patients careful echocardiographic examination of the atrioventricular junction in early infancy revealed the possibility of biventricular repair based on the favorable anatomy of the atrioventricular valve and balanced ventricles in the presence of an inlet ventricular septal defect (VSD). CASE PRESENTATIONS: Both patients presented in the neonatal period for evaluation of complex congenital heart disease. The anatomy of the atrioventricular valves in our patients was indistinguishable from atrioventricular septal defects exhibiting the morphology of a common valve with superior and inferior bridging leaflets. The common atrioventricular valve was connected exclusively to the right atrium draining into both ventricles while the left atrium drained into the right atrium via a secundum atrial septal defect. In one of our patients biventricular repair with good longterm-result was performed by reseptation of the atria, patch repair of the VSD and septation of the atrioventricular valve. The second patient underwent univentricular palliation according to the Fontan principle. DISCUSSION/CONCLUSION: The echocardiographic findings in our patients suggest that at least some patients with UBC represent a variant of atrioventricular septal defects associated with extreme ventriculoatrial malalignment resulting in fusion of the deviated primary atrial septum with the lateral aspect of the atrioventricular junction. This offers the option of septation of the common atrioventricular valve and biventricular repair in patients with adequate size of both ventricles. Exact echocardiographic analysis of the morphology of the atrioventricular valve is essential to distinguish these patients with a morphologically common atrioventricular valve in early infancy from other variants of absent atrioventricular connection and to select those who are suitable for biventricular repair.