Successful treatment of fulminant myocarditis due to COVID-19 in a 5-year-old girl.

Reports of acute myocarditis are increasing due to the worldwide spread of coronavirus disease 2019 (COVID-19). We report a case of a 5-year-old girl with fulminant myocarditis caused by COVID-19, who was successfully treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). The unvaccinated patient had developed fever 1 week before attending our hospital and was "presumptive positive" for COVID-19 based on the surrounding infectious situation. The fever resolved, but the day before the visit, abdominal pain appeared. The patient visited her previous physician with vomiting as the main complaint. She was transferred to our hospital due to impaired consciousness and bradycardia, with a heart rate of 40 beats/min. Immediately after transfer, she was diagnosed with complete atrioventricular (AV) block and was scheduled to undergo percutaneous pacing lead insertion. However, the patient had ventricular tachycardia, AV block and hypotension intraoperatively and required cardiopulmonary resuscitation. The patient was in an extremely unstable circulatory state, and VA-ECMO was urgently introduced. After multidisciplinary treatment for acute myocarditis, waiting for an improvement in AV block, and recovery of cardiac function, the patient was weaned from VA-ECMO on the eighth day after admission. The patient was discharged with no cardiac or neurologic sequelae. Learning objective: The rapid introduction of veno-arterial extracorporeal membrane oxygenation for fulminant myocarditis caused by coronavirus disease 2019 (COVID-19) in young children is extremely effective. Vaccination may be important for preventing infection with COVID-19 and avoiding severe complications.

Timing of Haemophilus influenzae type b vaccination after cardiac surgery.

BACKGROUND: The best time for vaccination in infants with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) surgery is unclear, but it is important to prevent Haemophilus influenzae type b (Hib) infection in infants with CHD after CPB surgery. To identify the best time for Hib vaccination in infants with CHD after CPB surgery, we investigated the immunological status, and the efficacy and safety of Hib vaccination after CPB surgery. METHODS: Sixteen subjects who underwent surgical correction of ventricular septal defect with CPB were investigated. Immunological status and cytokines were analyzed before surgery, 2 months after surgery, and before Hib booster vaccination. Hib-specific IgG was also measured to evaluate the effectiveness of vaccination. RESULTS: Immunological status before and 2 months after surgery (e.g. whole blood cells and lymphocyte subset profile) was within the normal range and no subjects had hypercytokinemia. Additionally, all subjects who received Hib vaccination at 2-3 months after CPB surgery had effective serum Hib-specific IgG level for protection against Hib infection without any side-effects. CONCLUSIONS: CPB surgery does not influence acquired immunity and Hib vaccination may be immunologically safe to perform at 2 months after CPB surgery. Hib vaccination at 2-3 months after CPB surgery was effective in achieving immunization for infants with simple left-right shunt-type CHD.

Right ventricular failure with high echoic ventricular wall change after foetoscopic laser photocoagulation: a case report of a donor in twin-to-twin transfusion syndrome.

The introduction of foetoscopic laser photocoagulation has dramatically improved the prognosis of patients with severe twin-to-twin transfusion syndrome. We present the case of a donor who exhibited right-heart failure with a high echoic wall change of the right ventricle after the foetoscopic laser photocoagulation procedure. The prenatal and 1-year postnatal follow-up revealed the gradual recovery of the right ventricular function.

Clinical utility of the plasma brain natriuretic peptide level in monitoring tetralogy of fallot patients over the long term after initial intracardiac repair: considerations for pulmonary valve replacement.

Clinicians are currently encountering an increasing number of patients in the long-term period after tetralogy of Fallot (TOF) repair presenting with pulmonary valve regurgitation (PR) or right ventricular (RV) dysfunction. The purpose of this study was to evaluate the clinical utility of the plasma brain natriuretic peptide (BNP) level and consider surgical indications and timing of pulmonary valve replacement (PVR). We examined 33 patients (21 males, 12 females, mean age 14.5 ± 2.8 years) who underwent TOF repair at Kitasato University Hospital. All patients were evaluated using echocardiography and blood sampling. The mean age at the time of initial repair was 1.3 ± 0.7 years. The patients with moderate-severe PR exhibited significantly higher plasma BNP levels than the patients with trivial-mild PR (mean 37.5 ± 33.1 vs. 17.3 ± 6.6 pg/ml, p = 0.013). The mean plasma BNP level with cardiac symptoms was higher than that observed in the patients without any symptoms (71.4 ± 46.1 vs. 25.0 ± 14.0 pg/ml, p = 0.005). The mean BNP level was significantly decreased after PVR (71.3 ± 46.1-26.1 ± 13.2 pg/ml, p = 0.009), and the plasma BNP level was found to be positively correlated with the RV end-diastolic pressure (r = 0.851; p = 0.008). The optimal BNP cut-off value for considering PVR was 32.15 pg/ml (sensitivity, 85.7 %; specificity, 83.3 %). The plasma BNP level may become a useful diagnostic tool for considering the indications and optimal timing of PVR over the long term after TOF repair.

Quantitative evaluation of hemodynamics in the Fontan circulation: a cross-sectional study measuring energy loss in vivo.

Flow energy loss (EL) at the Fontan anastomosis has been thought to reflect flow efficiencies and to influence on hemodynamics in the Fontan circulation and has been often discussed in numerical studies. However, in vivo EL measurements have to date not been reported. We directly measured EL in the Fontan circulation and examined the relationship between the structural configuration and EL, as well as the influence of EL, on the hemodynamics in the Fontan circulation. We performed a catheterization study measuring simultaneous pressure and flow velocity to calculate EL in nine patients (mean age 2.3 ± 0.3 years) 1 year after the Fontan procedure. The measured EL was 9.66 ± 8.50 mW. One patient with left pulmonary artery stenosis recorded the highest EL (17.78 mW), and one patient with bilateral superior vena cava and left phrenic nerve palsy recorded the second highest EL (14.62 mW). EL significantly correlated with time constant tau and weakly with max-dp/dt during the isovolumic diastolic phase (r = 0.795 and -0.574, respectively). EL also correlated with max-dp/dt during the isovolumic systolic phase (r = 0.842) but not with ejection fraction or systemic blood flow (r = 0.384 and -0.034, respectively). In conclusion, inefficient structural configuration and phrenic nerve palsy seem to be related with increased in EL at the Fontan anastomosis. Although these preliminary findings also suggest that EL is associated with an impaired relaxation of the ventricle, a long-term study with a large population is warranted to reach such a definitive conclusion.

A novel strategy for hemolytic uremic syndrome: successful treatment with thrombomodulin α.

Hemolytic uremic syndrome (HUS) is a life-threatening infectious disease in childhood for which there is no confirmed therapeutic strategy. Endothelial inflammation leading to microthrombosis formation via complement activation is the main pathology of HUS. Thrombomodulin is an endothelial membrane protein that has anticoagulation and anti-inflammatory effects, including the suppression of complement activity. Recombinant human soluble thrombomodulin (rTM) is a novel therapeutic medicine for disseminated intravascular coagulation. We administered rTM to 3 patients with HUS for 7 days and investigated the outcomes in view of the patients' prognoses, changes in biochemical markers, complications, and adverse effects of rTM. Symptoms and laboratory data improved after initiation of rTM in all 3 patients. Abnormal activation of complements was also dramatically suppressed in 1 patient. The patients recovered without any complications or adverse effects of rTM. They were discharged having normal neurologic status and with no renal dysfunction. To our knowledge, this is the first report of rTM being used to treat HUS. These case reports show the positive effect of rTM in patients with HUS. Randomized controlled studies should be performed to assess the efficacy and safety of rTM for children with HUS.