Change Over Time in Seasonality and Severity of Children Hospitalized With Respiratory Syncytial Virus Infection in Japan.

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis, and in temperate climates, late fall and winter epidemics of bronchiolitis are usually linked to RSV. In recent years in Japan, the RSV infection epidemic has occurred earlier, even during the hot season. This study aimed to evaluate the seasonal variation of RSV-associated hospitalizations over the past decade and the relationship between season and disease severity. METHODS: This was a retrospective single-center study. Hospitalized children were studied between 2011 and 2019. RSV was detected using rapid antigen detection tests. Clinical information was obtained from medical records, and patients were classified by 4 seasons of admission and analyzed for changes over time. RESULTS: Among 3750 children, 945 (25.2%) were RSV-positive. The seasonal proportion of hospitalized children who are RSV-positive showed a peak shift towards summer, with a turning point in 2016. Comparing 2011-2012 and 2018-2019, incidence increased from 6.8% to 46.3% during summer, whereas during fall decreased from 50.0% to 20.7% and decreased from 28.4% to 20.7% during winter ( P < 0.05). A similar trend was observed in the number of children requiring oxygenation in the earlier period; however, after the transition, there was no significant difference between seasons. CONCLUSIONS: Our findings showed that the RSV epidemic shifted to peak during summer until 2016. There was an association between seasonality and severity, such that many younger children were hospitalized during the autumn and winter and required more oxygen; however, after 2016, this difference was no longer observed.

Successful arterial switch operation for transposition of the great arteries with intact ventricular septum and congenital diaphragmatic hernia: A case report.

We report performing a successful arterial switch operation on a full-term male infant with transposition of the great arteries and intact ventricular septum associated with a congenital diaphragmatic hernia. The patient developed severe persistent pulmonary hypertension after successful repair of a left congenital diaphragmatic hernia that restricted pulmonary blood flow into the hypoplastic left lung, and subsequent unilateral pulmonary congestion of the unaffected right lung occurred because of the hemodynamics generated by the transposition of the great arteries. Intravenous epoprostenol with nitric oxide inhalation and mechanical hypoventilation effectively controlled pulmonary vascular resistance before the arterial switch operation was performed. .

Intrauterine hemodynamics of tricuspid valve dysplasia in a growth-restricted infant.

We present a case of fetal tricuspid valve dysplasia, which was diagnosed at 22 weeks of gestation during a routine obstetrical examination. Serial fetal echocardiographic evaluation revealed progressive right ventricular outflow tract obstruction and persistent cardiomegaly. A female infant weighing 1,916 g was delivered by elective cesarean section at 38 weeks of gestation. Longstanding compression of the fetal lungs secondary to the persistent cardiomegaly resulted in severe respiratory distress and cyanosis immediately after birth. Although, mechanical ventilation and continuous infusion of prostaglandin were instituted, the infant died of respiratory failure at 21 days of age. During the pregnancy, the fetus exhibited intrauterine growth restriction, but hydrops did not occur. In regard to the fetal hemodynamics in this cardiac anomaly, transatrial communication is essential for fetal survival. The diameter of the fossa ovalis, which is a marker of transtrial blood flow, was adequate in this case. However, marked enlargement of the right heart associated with regurgitation interfered with left ventricular filling and output, which resulted in restriction of the combined ventricular output and intrauterine fetal growth restriction.

Cardiomyocyte regeneration from circulating bone marrow cells in mice.

We investigated the role of circulating bone marrow cells (BMC) in cardiomyocyte regeneration. BMC, isolated from transgenic mice expressing enhanced green fluorescent protein (GFP), were transplanted into lethally irradiated C57BL6 mice. Five weeks after bone marrow transplantation (BMT), flow cytometric analysis for GFP-positive cells confirmed reconstitution of transplanted bone marrow. Bone marrow transplant mice subsequently underwent left coronary artery ligation (myocardial infarction) or sham-operation, and were killed at 1 mo or 3 mo after operation. Infarct size was similar in bone marrow transplant mice at 1 mo (47.1 +/- 5.9%) and at 3 mo (45.3 +/- 7.8%), and echocardiography at 2 and 8 wk revealed decreasing left ventricular function. In infarcted heart, GFP-positive cells that expressed desmin and troponin T-C were identified by confocal microscopy. GFP and troponin T-C double-positive cells were predominantly in the peri-infarcted region (1 mo, 365 +/- 45 cells/50 sections; 3 mo: 458 +/- 100 cells/50 sections; p < 0.05 versus noninfarct, infarct, and sham-operated regions). Furthermore, BMC mobilization and differentiation into cardiomyocytes was found to be complete within 1 mo after myocardial infarction. These results demonstrate that circulating BMC undergo mobilization and differentiation in cardiac cells after myocardial infarction. Future studies are required to determine the molecular signaling mechanisms responsible for this phenomenon.

Evolution of staged approach for Fontan operation.

BACKGROUND: During the early development of the Fontan operation, a number of physiologic and anatomical limits were proposed as selection criteria, and two criteria, pulmonary vascular resistance and ventricular function, have been important in predicting surgical outcome. The use of the bidirectional cavo pulmonary shunt as a staging procedure performed to control the pulmonary blood flow adequately and reduce ventricular volume over load has resulted in marked improvements in the early and late Fontan procedure results. METHODS AND RESULTS: At our hospital we perform systemic pulmonary shunt or pulmonary artery banding in patients if pulmonary blood flow can not be controlled adequately in the neonatal period and then perform bidirectional cavo pulmonary shunt six months afterwards. During this operation we also performed simultaneous surgical repair for pulmonary artery distortion, anomalies of pulmonary venous connection, restriction of bulboventricular foramen and atrioventricular valve regurgitation. To determine the efficacy of this staged approach in avoiding increases in pulmonary vascular resistance and impaired ventricular function, surgical results were investigated. From February 1995 to May 2001, eighteen patients with cardiac morphology unsuitable for biventricular repair were admitted to our hospital. Twenty-six palliative procedures, were performed including seven pulmonary artery banding, three systemic pulmonary shunt, thirteen bidirectional cavo pulmonary shunt, one original Glenn procedure, four repair of coarctation of the aorta, two total anomalous pulmonary venous connection repair, one mitral valve plasty, and two patients required Damus-Kaye-Stansel procedure to release restrictive bulboventricular foramen. Fifteen patients underwent a modified Fontan operation (total cavopulmonary connection) after these palliative procedures. The operative mortality rate for these palliative procedures was 3.8% (1/26). The operative mortality rate for Fontan operation was 7.1% (1/14). Three patients awaiting the Fontan operation were considered good candidates for a final operation and no patients in this series were considered unsuitable for Fontan completion. CONCLUSION: Our strategy of staged approach for Fontan procedure offers a good prognosis.

Longitudinal evaluation of anthracycline cardiotoxicity by signal-averaged electrocardiography in children with cancer.

BACKGROUND: The aim of the present study was to investigate the detection of anthracycline cardiotoxicity by signal-averaged electrocardiography (SAE) in children with cancer. METHODS: There were 29 patients with a cumulative anthracycline (ATC) dose of 75-600 mg/m2. None of them had congestive heart failure. Patients underwent SAE just before (detection of chronic cardiotoxicity) and just after (detection of acute cardiotoxicity) ATC therapy. Echocardiography and Holter electrocardiography were performed at the same time. The rates of abnormal SAE, echocardiography, and electrocardiogram findings were calculated and compared for every 100 mg/m2 of ATC. RESULTS: The SAE showed a significantly higher detection rate for acute cardiotoxicity was at a cumulative ATC dose of less than 400 mg/m2 when compared with other methods (P < 0.05). The lowest dose at which acute cardiotoxicity was detected by SAE was 117.3 mg/m2. The detection of chronic cardiotoxicity by SAE was significantly higher at a cumulative ATC dose of 100-400 mg/m2 when compared with other methods (P < 0.05), and the lowest value showing toxicity was 373.3 mg/m2. The lowest ATC dose causing chronic cardiotoxicity was significantly lower in patients less than 2-years-old (120.0 +/- 28.3 mg/m2) than in the other age groups (P < 0.05). CONCLUSIONS: Acute and chronic ATC cardiotoxicity were detected by SAE at lower cumulative doses compared with other methods. The technique of SAE was a potentially useful method for detection of cardiotoxicity among those investigated and it provides useful information on subclinical cardiac dysfunction in patients receiving ATC therapy.