Etiology and clinical course of severe and extreme thrombocytosis in children: a retrospective single-center study.

The aim of this study was to describe the etiology and clinical course in children with severe thrombocytosis (ST, platelet counts > 900 × 109/L) and extreme thrombocytosis (ET, platelet counts > 1000 × 109/L) in a tertiary pediatric hospital. Patients aged 0-18 years with platelet counts over 900 × 109/L who were admitted to our hospital were analyzed. Thrombocytosis was defined as a platelet count exceeding 450 × 109/L. Thrombosis was diagnosed based on computed tomography scans or ultrasound findings. Potential factors associated with the development of extreme thrombocytosis were identified using logistic regression models. Only one (0.8%) out of the 120 patients identified with ST (n = 61) and ET (n = 59) had primary thrombocytosis. The most common underlying condition was congenital heart disease (26.7%), followed by Kawasaki disease (16.7%). With the exception of the hemoglobin level, no major differences were found for the baseline characteristics between the ST and ET groups. A lower hemoglobin level (< 10.0 g/dL) at the onset of thrombocytosis was identified as a predictor for ET development (adjusted odds ratio 2.73, 95% confidence interval 1.18-6.28). Overall, 56 of 120 (46.7%) patients received aspirin therapy. Venous thrombosis occurred in one (0.8%) patient. CONCLUSIONS: We found a low proportion of primary thrombocytosis and a low incidence of thrombosis in children with ST and ET. Our results suggest that pediatric ST and ET may share common characteristics and may have features that are distinct from those in adults. WHAT IS KNOWN: • Secondary thrombocytosis is a frequent finding in children. • Adult extreme thrombocytosis has been found to be associated with primary thrombocytosis. WHAT IS NEW: • There were no major differences in the baseline characteristics between children with severe and extreme thrombocytosis. • The incidence of thrombosis was markedly low in both severe and extreme thrombocytosis groups.

A case of infective endocarditis in an 8-year-old boy 3 months after transcatheter atrial septal defect closure using Figulla Flex II occluder.

Infective endocarditis is a rare complication of atrial septal defect closure using transcatheter procedure. We report about infective endocarditis in an 8-year-old boy 3 months after transcatheter closure using a Figulla Flex II atrial septal defect occluder. Transesophageal echocardiography showed vegetation attached to the left atrium side of the device. Device removal and atrial septal defect closure were performed. The device was less endothelialized on the left than on the right atrium side. Therefore, insufficient endothelialization may cause infective endocarditis.

Surgical management of congenital lobar emphysema associated with CHD.

Congenital lobar emphysema is often associated with CHD in early infancy; however, the surgical strategy for this condition is still controversial. We report three successful cases of emphysematous lung lobectomy before the surgical repair of associated CHD. Aggressive lobectomy preceding cardiac interventions is advised when the management of congenital lobar emphysema is difficult.

Influence of Gamma Irradiation and Water Aging on the Space Charge Characteristics of Epoxy Micro-Nano Composites.

Epoxy micro-nano composites are well-known to exhibit enhanced electrical, mechanical as well as thermal properties compared to base epoxy resin. Yet, a clear understanding need to be achieved on the long-term aging performance of the epoxy micro-nano composites. The present review article is a comprehensive study on the impact of gamma irradiation and water aging on the space charge characteristics of epoxy micro-nano composites that are applicable as insulant in high-voltage power apparatus. Ion-trapping nanoparticles, which possess good oxidation resistance and high ion trapping ability, are being chosen as nanofillers along with silica micro fillers in epoxy micro-nano composite material for improving the reliability of electrical insulation structures. The epoxy micro-nano composite specimens were subjected to gamma irradiation (4 kGy and 8 kGy) and water aging (under room temperature and at 90 °C), to analyze the effect of aging on space charge accumulation and charge decay characteristics. The mean magnitude of accumulated space charge density of epoxy micro-nano composites tends to increase with an increase in gamma irradiation dose as well as an increment in water diffusion coefficient. The mean lifetime of the space charge decay during depoling has significantly reduced after gamma irradiation and is converse with water aged specimen. Voltage polarity reversal studies have indicated that a part of homo-charge injected from electrodes remained as hetero-charge just after polarity reversal and could result in the distortion of electric field thereby increasing the electric field enhancement factor.

The Effect of Hypoxic Gas Therapy Using Nitrogen Before Bilateral Pulmonary Artery Banding on Hemodynamics and Pulmonary Artery Development.

This study aimed to identify its influence on pulmonary development and hemodynamics before bidirectional Glenn (BDG) anastomosis. This retrospective study involved 30 consecutive patients with univentricular hearts who underwent bilateral pulmonary artery banding (bil-PAB) and BDG anastomosis between September 2011 and September 2018 at our institution. These patients were classified into the nitrogen (N = 12) and no nitrogen (N = 18) groups according to their use of hypoxic gas therapy. Clinical echocardiographic, operative, and catheter examination data were reviewed. Nakata index was 131 (110-167) in the nitrogen group and 138 (88.4-161.7) in the no nitrogen group (P = 0.8). Pulmonary vascular resistance (PVR) was 1.50 (1.30-2.4) in the nitrogen group and 138 (88.4-161.7) in the no nitrogen group (P = 0.3). There was no statistical difference between the pulmonary development in both groups. In the subgroup of hypoplastic left heart syndrome patients, there was a statistical difference. RVEDV% of normal was 232.5 (215-239) in the nitrogen group and 201 (161-209) in the no nitrogen group (P = 0.03). Pulmonary development was not significantly different when hypoxic gas therapy was performed using nitrogen vs. not using nitrogen. However, RVEDV% of normal might be larger with hypoxic gas therapy using nitrogen. Although there is no obvious systemic atrioventricular valve regurgitation exacerbation with hypoxic gas therapy, it might be useful to prevent a decrease in PVR and may also affect bil-PAB and subclinical increase in systemic atrioventricular valve regurgitation.

Mid-term outcomes of cor triatriatum repair: comparison of biventricular physiology and univentricular physiology.

BACKGROUND: Cor triatriatum is the rarest of all congenital cardiac diseases, accounting for 0.1-0.4% of congenital heart diseases. Atrial septal defect is the most common associated defect; however, cor triatriatum is sometimes associated with univentricular heart. METHODS: This single-centre retrospective study involved all patients who underwent the repair of cor triatriatum at Kobe Children's Hospital between 2000 and 2020. Twenty-four patients were required surgery. We conducted a survey of survival rate, early and late pulmonary vein stenosis in each group. RESULTS: The survival rate of 5 years after cor triatriatum resection was 100% in the biventricular group and 82.1% in the univentricular group, respectively. The free rate for pulmonary stenosis of 5 years after surgery was 100% in the biventricular group and 90.0% in the univentricular group, respectively. There was no statistical difference in survival rate and 5 years free rate for pulmonary stenosis after surgery. CONCLUSIONS: The results showed that surgical correction offers good early and mid-term outcomes for both cor triatriatum with biventricular and univentricular physiologies.

Double drainage of total anomalous pulmonary venous connection revealed after surgical repair of a supracardiac total anomalous pulmonary venous connection.

Mixed type TAPVC with double drainage, where the second vertical vein enlarged rather than atrophied after surgery. If we did not recognize left-to-right shunting before surgery, it can be treated with catheterization as demonstrated by our case.

Successful balloon valvuloplasty using direct puncture of the heart for pentalogy of Cantrell with complete ectopia cordis, low birth weight, single ventricle and severe pulmonary stenosis.

We present a 31 gestational weeks' premature baby whose fetal echocardiogram showed ectopia cordis, single ventricle and severe pulmonary stenosis. At 31 gestational weeks, an emergency caesarean section was performed, and his birth weight was 1756 g, SpO2 was 80% on 100% O2. Epicardial echocardiogram showed double inlet right ventricle, severe valvular pulmonary stenosis and no ductus arteriosus. The risk of surgery was very high, so we decided to perform balloon valvuloplasty by direct puncture of the heart. We punctured the apex of the ventricle using a 16-gauge needle under echo guidance, advanced the guidewire to the pulmonary artery and performed balloon valvuloplasty. Soon after the procedure, the cyanosis improved dramatically. This is the first report of a transcatheter procedure performed by direct puncture of the heart for ectopia cordis with complex congenital heart disease.

Computed tomography-based surgical strategy for total anomalous pulmonary venous connection.

OBJECTIVES: We used computed tomographic angiography (CTA)-based surgical planning to clarify the anatomical indications of sutureless repair technique for total anomalous pulmonary venous connection. The mid-term impact of the current surgical strategies was evaluated. METHODS: One hundred twelve patients underwent repair for total anomalous pulmonary venous connection. The study period was divided into era 1 (1996-2010, n = 56) and era 2 (2011-2018, n = 56). Patients with single ventricular heart (SVH) were included. In era 2, the indications for primary sutureless repair and branch pulmonary vein incision were based on CTA findings. RESULTS: For patients with biventricular heart, the 5-year survival was 69% and 97% in eras 1 and 2, respectively (P = 0.0024). For patients with SVH, the 5-year survival was 21% and 70% in eras 1 and 2, respectively (P = 0.0007). During the follow-up period, the evidence of post-repair pulmonary vein stenosis (PVS) was observed in 12 patients with biventricular heart [era 1, 8 patients (23%); era 2, 4 patients (13%)], and 14 patients with SVH [era 1, 6 patients (60%); era 2, 8 patients (36%)]. Using multivariable analysis, preoperative CTA was associated with improved survival in both biventricular heart and SVH and associated with post-repair PVS-free survival in SVH. Since 2011, 12 patients with post-repair PVS underwent multiple reintervention with 1 recorded death (5-year survival: 88%). CONCLUSIONS: CTA-based surgical strategy for total anomalous pulmonary venous connection provided significant survival benefit. Although post-repair PVS could occur in era 2, aggressive reintervention appeared to be associated with improved survival and vein patency.

Acute encephalopathy with biphasic seizures and late reduced diffusion accompanied by Takotsubo cardiomyopathy.

BACKGROUND: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized by biphasic seizures and impaired consciousness. Takotsubo cardiomyopathy (TTC), which is typically triggered by psychological or physical stress, is characterized by transient myocardial dysfunction affecting the left ventricular apex. Recent reports have suggested that seizures can also trigger TTC. However, no cases of TTC accompanied by AESD have been reported. PATIENT: A previously healthy 4-year-old girl was brought to a hospital with first-time febrile generalized tonic-clonic convulsions, which lasted approximately 40 min. After the seizure resolved, she was intubated due to respiratory deterioration. On the next day, her cardiac function deteriorated, and echocardiography revealed systolic apical ballooning of the left ventricle accompanied by hyperkinesis of the basal wall, which are typical in patients with TTC. Her condition gradually improved, and catecholamine support was tapered. However, 6 days after admission, she experienced a cluster of brief convulsions. Ten days after admission, head MRI revealed lesions with reduced diffusion throughout the cortex, except in the occipital lobe, as well as perirolandic sparing. Follow-up MRI 35 days after onset revealed whole-brain atrophy, following which she developed severe cognitive dysfunction. CONCLUSIONS: Our patient developed TTC accompanied by features of AESD. Our findings may thus provide insight into the development of TTC and prompt further studies regarding the relationship between prolonged seizures and TTC.

Successful living donor liver transplantation after stent implantation in a patient with Alagille syndrome and severe bilateral pulmonary artery stenosis.

Severe pulmonary hypertension is a contraindication for liver transplantation owing to high mortality. However, decision-making regarding the treatment approach for patients with bilateral peripheral pulmonary artery stenosis, typically complicated by elevated main pulmonary artery and right ventricle pressures, can be challenging. Here, we report successful living donor liver transplantation after bilateral pulmonary artery stent implantation in a patient with Alagille syndrome, severe bilateral peripheral pulmonary artery stenosis, and extremely high main pulmonary artery and right ventricle pressures.

Co-occurrence of hypertrophic cardiomyopathy and juvenile myelomonocytic leukemia in a neonate with Noonan syndrome, leading to premature death.

We report a case of a neonate with Noonan syndrome presenting with concurrent hypertrophic cardiomyopathy and juvenile myelomonocytic leukemia, which resulted in premature death. Cases with Noonan syndrome diagnosed during the neonatal period might not necessarily show mild clinical course, and premature death is a possible outcome to be considered.

Maximum QTc on Holter electrocardiography in children.

BACKGROUND: Corrected QT interval (QTc) on electrocardiography (ECG) at rest and after exercise in a short daytime recording period may be insufficient for the diagnosis and management of long QT syndrome (LQTS), especially for LQTS type 2 and 3. Therefore, examination of QTc on Holter ECG is important. We designed a method of analyzing QTc on Holter ECG that can be performed in daily clinical practice by combining automatic and manual measurements. METHODS: We reviewed the charts of healthy children (n = 210) and LQTS patients (n = 35) aged <16 years and analyzed QTc at rest and after exercise, and the maximum QTc on Holter ECG. RESULTS: The QTc (Fridericia's correction) of most controls and LQTS patients reached the maximum at night or early in the morning. QTc differed according to sex and age. In the control group, QTc on ECG of all three types tended to lengthen with age. QTc after exercise was slightly longer than QTc at rest, and the maximum QTc on Holter ECG was much longer than both, reaching >450 ms in boys and 500 ms in girls. In most LQTS type 1 patients, QTc after exercise and that on Holter ECG tended to be long. In most LQTS type 2 and 3 patients, QTc at rest and that after exercise was long, and that on Holter ECG tended to be much longer. CONCLUSIONS: The present method of analyzing QTc on Holter ECG, in which automatic and manual measurements are combined, is practical and may be useful for diagnosis and risk stratification of LQTS.

Functional near-tricuspid atresia in a patient with absent pulmonary valve and an intact ventricular septum.

Absent pulmonary valve with an intact ventricular septum is a rare malformation. We report a case of absent pulmonary valve and intact ventricular septum with functional near-tricuspid atresia caused by pulmonary regurgitation. Initial palliation with main pulmonary artery ligation and bilateral pulmonary artery banding was performed at 1 day of age. More antegrade flow across the tricuspid valve was recognised postoperatively, resulting in a successful right ventricular outflow tract reconstruction by a hand-sewn bileaflet polytetrafluoroethylene valve and modified Blalock-Taussig shunt at 11 days of age.

Reproducibility of corrected QT interval in pediatric genotyped long QT syndrome.

Reproducibility of corrected QT interval (QTc), especially QTc after exercise, has not been thoroughly investigated. We reviewed charts of pediatric patients who underwent treadmill-exercise stress testing without medication multiple times within 1 year. In patients with long-QT syndrome (LQTS; n = 22), the discrepancy in QTc between two treadmill exercise stress tests using Fridericia's formula was 14 ± 12 ms at rest, 13 ± 12 ms 4 min after exercise, with a maximum of 14 ± 12 ms after exercise. There was no statistically significant difference in QTc between the two tests. Intraclass correlation coefficients (ICC) were 0.84, 0.85, and 0.85, respectively. In controls (n = 13), the discrepancy in QTc was 18 ± 12 ms at rest, 14 ± 7 ms 4 min after exercise, with a maximum of 14 ± 9 ms after exercise. There was no significant difference in QTc between the two tests. ICC were 0.78, 0.80, and 0.80, respectively. QTc calculated using Bazett's formula also showed high reproducibility. Reproducibility of QTc in children is high at rest and after exercise.

Coexistence of congenital long QT syndrome and autonomic dysregulation in children.

Loss of consciousness (LOC) in long QT syndrome (LQTS) patients can be caused by torsade de pointes (TdP) or vasovagal syncope (VVS). On genetic testing and head-up tilt testing (HUTT), we diagnosed three young patients with both genotyped LQTS and autonomic dysregulation. According to grade of prolongation of QT interval and LOC status, syncope episodes in two patients were classified as due to VVS, while those of the other patient were due to TdP. We also diagnosed one patient with postural orthostatic tachycardia syndrome. Syncope in LQTS patients should not automatically be labeled TdP. If there is a possibility of VVS, HUTT should be performed, but careful observation is required because TdP cannot be completely ruled out.

Clinical assessment of diastolic retrograde flow in the descending aorta for high-flow systemic-to-pulmonary artery shunting.

OBJECTIVE: To investigate whether echocardiographic characteristics in the descending aorta of patients with cyanotic congenital heart disease who have received a systemic-to-pulmonary artery (SP) shunt can indicate shunt flow volume and predict postoperative adverse events related to high-flow shunting. METHODS: Among the 73 consecutive patients who received an SP shunt between 2010 and 2014, data for 53 patients who underwent postoperative Doppler echocardiographic assessment of diastolic retrograde flow in the descending aorta (dAo-RF) were reviewed retrospectively. RESULTS: The mean dAo-RF ratio was 0.50 ± 0.15 at intensive care unit admission and reached its peak level (0.56 ± 0.12) at 24 hours after surgery. All of the patients with a maximal dAo-RF ratio of ≥0.80 had experienced acute heart failure or cardiogenic shock due to postoperative high-flow shunting and required emergent surgical interventions to reduce pulmonary blood flow. Pulse oximetry-measured oxygen saturation and serum lactate level were significantly correlated with dAo-RF ratio, but they had some clinical dispersion to match the postoperative adverse events. CONCLUSIONS: The dAo-RF ratio is a simple, repeatable, and noninvasive index for postoperative assessment of SP shunt flow volume. A high dAo-RF ratio is a significant predictor of postoperative adverse events of high-flow shunting.

Pacing therapy in children.

BACKGROUND: The importance of ventricular pacing site in pediatric pacemaker therapy has gradually become recognized. We reviewed our experience with a left ventricular (LV)-prioritized pacing strategy. METHODS AND RESULTS: Between 2000 and 2012, 60 patients underwent 76 permanent pacemaker implantations. Eight of the 29 reoperations involved ventricular lead repositioning for pacing-induced ventricular dysfunction. Freedom from ventricular lead failure was 96.3%, 86.8%, and 81.0% at 1, 3, and 5 years, respectively. The independent predictors of ventricular lead failure were age (P=0.026) and peak minimal energy threshold within 6 months (P=0.035). At the measured points, redo bipolar, steroid-eluting leads had significantly better pacing properties than did redo non-steroid-eluting, screw-in leads (P=0.0009-0.03). Ventricular lead repositioning was effective in the 5 patients with systemic LV pacing, whereas its efficacy was inconsistent in patients with single-ventricle or systemic right ventricular (RV) pacing. At a median follow-up of 59 months, the 28 patients with LV pacing had preserved ventricular function (LV fraction shortening, 0.34±0.09). CONCLUSIONS: The outcome of this LV-prioritized pacing strategy in pediatric patients was excellent, demonstrating preserved ventricular function. Bipolar, steroid-eluting, epicardial pacing leads achieved good pacing properties, even in reoperation patients. In children with systemic LV and RV pacing-induced ventricular dysfunction, a conversion to LV apex pacing was an attractive alternative to cardiac resynchronization therapy.