Treatment strategy for acute myocarditis in pediatric patients requiring emergency intervention.

BACKGROUND: Patients with acute myocarditis present with a wide range of symptoms. Treatment strategies for pediatric patients with circulatory failure comprise extracorporeal membrane oxygenation (ECMO), emergency temporary pacing, and pharmacotherapy. However, they remain controversial. ECMO is an effective treatment but gives rise to several complications; the goal is therefore to avoid excessive treatment as much as possible. We aimed to evaluate the importance of electrocardiogram findings in differentiating severity and establish an appropriate treatment strategy in pediatric patients with acute myocarditis who required emergency interventions. METHODS: This retrospective study enrolled pediatric patients admitted to and treated in our hospital for acute myocarditis between April 1983 and December 2021. Patients were retrospectively divided into whether circulatory failure occurred (ECMO or temporary pacing was needed; emergency intervention group) or not (pharmacotherapy alone). RESULTS: Of the 26 pediatric patients, 11 experienced circulatory failure while 15 did not. In the circulatory failure group, six patients were treated with ECMO (ECMO group) and five patients with temporary pacing (pacing group). In the pacing group, all patients were diagnosed with complete and/or advanced atrioventricular block (CAVB and/or advanced AVB) and narrow QRS. Furthermore, these patients improved only with temporary pacing and pharmacotherapy, without requiring ECMO. Wide QRS complexes (QRS ≥ 0.12 ms) with ST-segment changes were detected on admission in five of six patients in the ECMO group and none in the pacing group (P = 0.015). Although all patients in the ECMO group experienced complications, none did in the pacing group (P < 0.008). CONCLUSIONS: Regarding emergency intervention for acute myocarditis, ECMO or temporary pacing could be determined based on electrocardiogram findings, particularly wide QRS complexes with ST-segment changes on admission. It is important to promptly introduce ECMO in patients with wide QRS complexes with ST-segment changes, however, patients with CAVB and/or advanced AVB and narrow QRS could improve without undergoing ECMO. Therefore, excessive treatment should be avoided by separating ECMO from temporary pacing based on electrocardiogram findings on admission.

A Case of Successful Biventricular Repair of the Transposition of the Great Arteries with a Coronary Anomaly Associated with an Atrioventricular Septal Defect.

The transposition of the great arteries (TGA) associated with a complete atrioventricular septal defect is a rare and serious congenital cardiac anomaly. In this report, we describe the successful biventricular repair of a TGA with a complete atrioventricular septal defect in an infant. Due to the low body weight of the patient and a complex coronary pattern anomaly, an arterial switch operation was executed, with the Mee procedure and pulmonary arterial banding as initial palliative measures when the infant was 22 days old and weighed 2.5 kg. Subsequently, atrioventricular septal defect repair using the modified one-patch method was performed when the patient was 1.3 years old and weighed 8.8 kg. Remarkably, the postoperative course of the patient demonstrated no notable incidents. To our knowledge, this is the first time a two-stage strategy was applied to repair these complex defects, presenting a promising approach for managing similar cases in future medical practice.

Late bacterial endocarditis after percutaneous atrial septal defect closure.

Percutaneous atrial septal defect closure is widely used as an alternative to surgical repair in many hospitals. Infective endocarditis related to occluding devices is commonly known, but following that atrial septal defect closure with a device in a child is rare. This report describes an 11-year-old girl who developed late-stage bacterial endocarditis following incomplete endothelialisation after a percutaneous procedure.

Association Between Deleterious SCN5A Variants and Ventricular Septal Defect in Young Patients With Brugada Syndrome.

OBJECTIVES: This study aimed to investigate the clinical characteristics of young patients with Brugada syndrome (BrS) with ventricular septal defect (VSD) and explore their genetic backgrounds. BACKGROUND: VSD is the most frequently occurring congenital heart disease among children. In contrast, BrS is a rare hereditary disease that is responsible for ventricular fibrillation and sudden cardiac death. Owing to their low incidence, the genetic background and clinical characteristics of patients with BrS with VSD have not been elucidated yet. METHODS: This study enrolled 36 individuals who were diagnosed with BrS when they were <20 years of age and performed genetic screening for SCN5A. The functional alteration in mutant Na+ channels was confirmed by patch clamp technique. RESULTS: Among the 36 patients with BrS, 5 had been diagnosed with VSD. This study found 14 heterozygous SCN5A variants in 15 unrelated patients. The 5 patients with VSD carried SCN5A variants, including R367S, R535∗, R893C, W1345C, and G1743R. The 3 missense variants (R893C, W1345C, and G1743R) have been proved to reduce peak Na+ current to <10%. A functional analysis of SCN5A R367S was performed and the variant was found to be nonfunctional. CONCLUSIONS: This study identified 5 loss-of-function SCN5A variants in 5 young patients with BrS with VSD. The study hypothesizes that altered blood flow in the right ventricular outflow tract leads to fibrosis and electrophysiological changes, predisposing the patients to earlier clinical presentation of BrS. In patients with VSD and ST-segment elevation in the right precordial leads, BrS should be considered and appropriate screening should be pursued accordingly.

De Vega Tricuspid Annuloplasty for Pediatric Patients: Growth Potential of the Plicated Annulus.

Although De Vega annuloplasty is an important option for pediatric patients with functional tricuspid regurgitation (TR), little is known about its long-term results, including the future of the plicated annulus. We retrospectively reviewed our experience with pediatric patients who underwent the De Vega annuloplasty between 2005 and 2020. Tricuspid valve assessments were performed by transthoracic echocardiography. The targeted diameter of annular plication was 80 to 90% of normal tricuspid diameter, according to the patient's condition. The study included 55 patients (41 with biventricular physiology (group B), 14 with univentricular physiology (group U)) with a median follow-up of 5.0 years. Median age at operation was 5.0 years. There was one late death due to severe mitral regurgitation. Tricuspid valve reoperation was required in five patients and the 10-year freedom from reoperation was 91.9% for the entire cohort. The 10-year freedom from the composite adverse outcome of death, reoperation, and significant TR was 79.2% in group B versus 56.6% in group U (p = 0.034). TR grade significantly decreased after surgery (p < 0.001), without significant aggravation during the postoperative follow-up. No patients presented tricuspid stenosis. Mean Z-scores of annular diameter immediately after operation and at the latest follow-up were - 0.65 ± 0.56 versus - 0.47 ± 0.65 (p = 0.57). De Vega annuloplasty is a safe, efficient, and durable procedure for functional TR in pediatric patients including those with univentricular physiology, allowing adequate growth of the plicated annulus without the progression of tricuspid stenosis.

Novel electrocardiographic criteria for short QT syndrome in children and adolescents.

AIMS: Although shortening of the corrected QT interval (QTc) is a key finding in the diagnosis of short QT syndrome (SQTS), there may be overlap of the QTc between SQTS patients and normal subjects in childhood and adolescence. We aimed to investigate electrocardiographic findings for differentiation of SQTS patients. METHODS AND RESULTS: The SQTS group comprised 34 SQTS patients <20 years old, including 9 from our institutions and 25 from previous reports. The control group comprised 61 apparently healthy subjects with an QTc of <360 ms who were selected from 13 314 participants in a school-based screening programme. We compared electrocardiographic findings, including QT and Jpoint-Tpeak intervals (QT and J-Tpeak, respectively), those corrected by using the Bazett's and Fridericia's formulae (cB and cF, respectively) and early repolarization (ER) between the groups. QT, QTc by using Bazett's formula (QTcB), QTc by using Fridericia's formula (QTcF), J-Tpeak, J-Tpeak cB, and J-Tpeak cF were significantly shorter in the SQTS group than in the control group. On receiver operating characteristic curve analysis, the area under the curve (AUC) was largest for QTcB (0.888) among QT, QTcB, and QTcF, with a cut-off value of 316 ms (sensitivity: 79.4% and specificity: 96.7%). The AUC was largest for J-Tpeak cB (0.848) among J-Tpeak, J-Tpeak cB, and J-Tpeak cF, with a cut-off value of 181 ms (sensitivity: 80.8% and specificity: 91.8%). Early repolarization was found more frequently in the SQTS group than in the control group (67% vs. 23%, P = 0.001). CONCLUSION: A QTcB <316 ms, J-Tpeak cB < 181 ms, and the presence of ER may indicate SQTS patients in childhood and adolescence.

Contrast Echocardiogram for the Evaluation of Streaming in a Single-Ventricle Patient.

In cases involving single ventricles, predicting streaming characteristics is difficult. Unfavorable streaming can cause decreased oxygen saturation. Judging whether desaturation results from decreased pulmonary flow or unfavorable streaming is critical. A 20-day-old infant with a single left ventricle underwent ductus arteriosus ligation and pulmonary artery banding to control high pulmonary flow. Severe desaturation presented postoperatively, which worsened to 68% despite pure-oxygen ventilation. A bedside contrast echocardiogram helped determine whether unfavorable streaming caused desaturation. It revealed systemic venous streaming predominantly directed to the aorta. Emergent balloon atrial septostomy facilitated mixing at the atrial level. Oxygen saturation promptly increased to 85%.

Increased satisfaction of maternity hospital staff involved in fetal telediagnosis.

Questionnaires were sent to 14 maternity hospital staff members for qualitative assessment at the start of fetal telediagnosis and at the end of the study using a five-point Likert scale: 5, I strongly think so; 4, I think so; 3, I can't decide; 2, I don't think so; 1, I never think so. Ten questionnaires were returned to us (71%). The results showed that the staff reported a significant increase in confidence in performing fetal cardiac screening (score 2.3 at start, 3.4 at study completion; P = 0.034), the rate of score increase rose with the number of telediagnoses (r = 0.72, P < 0.05), feedback from a specialist was very useful (4.4 and 4.9, respectively), and real-time image transmission was preferred over recorded images (score 3.7 vs 2.4, respectively; P = 0.042). The excellent educational effect of telemedicine is useful for staff members to improve their skills while nurturing their motivation, leading to the promotion of fetal cardiac screening in regional areas.

Accuracy of telediagnosis of fetal heart disease using ultrasound images transmitted via the internet.

We verified the feasibility of telediagnosis of fetal disease by (i) grading telediagnosis by a pediatric cardiologist into five confidence levels; and (ii) comparison of fetal telediagnosis with hands-on fetal diagnosis or postnatal diagnosis. In 114 patients suspected of having heart disease (real time, n = 15; recorded image transmission, n = 99), 79 patients were in level 5 (excellent), 17 in level 4 (good), eight in level 3 (fair), 10 in level 2 (poor), and no patients in level 1 (bad). The average was 4.5, and in 96 patients (84% of all) telediagnosis was accurate (above 4), whereas in 18 patients it was inaccurate (level 2 or 3). In re-examination of 25 patients, telediagnosis was confirmed in patients in level 4 and 5, whereas heart disease was missed in patients in levels 2 or 3. The correct diagnosis matched the high confidence level of a specialist based on recognizable transmitted images.

A medical link between local maternity hospitals and a tertiary center using telediagnosis with fetal cardiac ultrasound image transmission.

Information and communication technology has been widely applied to various fields, including clinical medicine. We report here a telediagnosis system using ultrasound image transmission. The effect of telediagnosis, using a medical link between local maternity hospitals and our children's medical center, was verified. The number of fetal telediagnosis for cardiac disease, and cases referred to a perinatal care center and emergent transportation of neonates with congenital heart disease from maternity hospitals, were calculated based on the hospital records. The percentage of patients found to have heart disease was compared between out-patient clinic and telediagnosis cases. Telediagnosis increased, allowing maternity hospital staff to obtain support easily from a specialist when making a diagnosis. Many severe cases were transferred to tertiary centers with the correct diagnosis; consequently, the number of emergent transportations of neonates with severe cardiac anomalies continued to below. Telediagnosis was also useful as an educational tool for maternity hospital staff, who improved their skills during conversations with a specialist. Unlike in the outpatient clinic, consultation by telediagnosis was requested even for cases of mild abnormalities, and the number of false-positives increased, while many cardiac anomalies were found in the early stage. Furthermore, telediagnosis was helpful for pregnant women requiring bed rest, and also had the advantage of allowing a doctor to be able to talk with parents. Establishing a fetal telediagnosis system is a useful strategy to improve neonatal care through a medical link between local maternity hospitals and a tertiary center.

Absence of the coronary sinus with coronary venous drainage into the main pulmonary artery.

We describe the case of a 9-year-old girl demonstrating isolated absence of the coronary sinus with abnormal coronary venous drainage into the main pulmonary artery. Coronary angiography showed normal coronary arterial trees and contrast medium from both coronary arteries drained into the main pulmonary artery via an abnormal cardiac vein on the anterior wall of the right ventricle.

[Magnesium metabolism and therapeutic strategy in cardiovascular disease].

Many epidemiological and clinical analysis have reported the relation between Mg and cardiovascular disease. Hypomagnesemia may be triggering mechanisms for ischemic heart disease, arrhythmias after open heart surgery, serious arrhythmias such as Torsades de Pointes (TdP) , and the negative feed back in congestive heart failure. Supplemental and therapeutic Mg infusion have been reported to reduce the mortality in acute myocardial infarction and having the cardioprotective effect after infarction (controversial) . It is also reported to reduce the incidence of arrhythmias after heart surgery, terminate the serious arrhythmias such as TdP, and improve the negative feed back in congestive heart failure. Magnesium metabolisms in cardiovascular disease are not necessarily clear. We expect the precise analysis of Mg actions and attractive Mg therapy in clinical literature.

Severe Peters Plus syndrome-like phenotype with anterior eye staphyloma and hypoplastic left heart syndrome: proposal of a new syndrome.

Peters Plus syndrome is a very rare autosomal recessive condition characterized by ocular defects (typically Peters anomaly) and other systemic major/minor anomalies. Mutations in the B3GALTL gene encoding beta 1,3-glucosyltransferase have been found in virtually all patients with typical Peters Plus syndrome. We report on a female patient with unusually severe manifestations of Peters Plus syndrome, including anterior eye staphyloma, cleft lip and palate, and hypoplastic left heart syndrome (HLHS). Analysis of the B3GALTL gene revealed no mutation in the patient. To our knowledge, HLHS has not previously been reported in Peters Plus syndrome so far, and anterior staphyloma, a most severe defect of the anterior eye chamber, is also apparently rare in the syndrome. Our patient might represent a new syndrome of severe Peters Plus syndrome-like phenotype with anterior eye staphyloma and HLHS.

Isolated non-compaction of the ventricular myocardium associated with long QT syndrome: a report of 2 cases.

Isolated non-compaction of the ventricular myocardium (INCVM) is a relatively newly defined clinicopathologic entity. INCVM is clinically accompanied by depressed ventricular function, arrhythmias, and systemic embolization. We report two cases of INCVM with long QT syndrome (LQTS). In both cases the QT interval was over 0.55 s with episodes of torsades de pointes, and prominent ventricular trabeculations and deep intertrabecular recesses were detected by 2-dimensional echocardiography. Both cases had the KCNH2 mutation. To the best of our knowledge, this is the first report investigating INCVM with LQTS.

Peripheral pulmonary artery aneurysms in patients with pulmonary artery hypertension.

Pulmonary artery aneurysm (PAA), especially the peripheral type, is a rare disease. We report 2 cases of peripheral PAA with pulmonary artery hypertension. Complication associated with peripheral PAA was hemoptysis. Endovascular coil embolization was performed successfully in one patient. The other with peripheral PAA was died of massive hemoptysis. In patients with peripheral PAA, coil embolization is one therapeutic option. We summarized cases with peripheral PAA in Japan.

Successful uses of magnesium sulfate for torsades de pointes in children with long QT syndrome.

BACKGROUND: Administration of magnesium sulfate (MgSO4) is an effective and safe treatment for torsades de pointes (TdP) associated with acquired long QT syndrome (LQTS) in adults. As for children, there are few reports focusing on it. The authors discuss the efficacy of MgSO4 for TdP in children with congenital and acquired LQTS. The authors also discuss the optimal administration dosage and serum magnesium (SMg) concentration during MgSO4 therapy. METHODS: The authors studied seven consecutive LQTS children undergoing MgSO4 therapy for TdP. Of the seven children, five were congenital LQTS and two were acquired LQTS. A bolus injection of MgSO4 was given intravenously over 1-2 min followed by continuous infusion for the next 2-7 days. RESULTS: Of the seven patients, six responded completely to the initial bolus. The bolus dosage was 5.9 +/- 3.8 mg/kg (range, 2.3-12 mg/kg) in these six, and the other remaining one (neonate with congenital LQTS) required a total of 30 mg/kg until complete abolishment. The continuous infusion was given at rates of 0.3-1.0 mg/kg per h and patients did not show recurrence of TdP. The SMg concentration was 3.9 +/- 1.0 mg/dL (2.9-5.4 mg/dL) immediately after bolus injection. The mean corrected QT (QTc) interval before and after bolus injection did not show significant difference. CONCLUSION: Intravenous infusion of MgSO4 was effective for TdP in children with LQTS, and MgSO4 abolished TdP without shortening the QTc interval. The optimal bolus dosage, infusion rates and SMg concentration were 3-12 mg/kg, 0.5-1.0 mg/kg per h and 3-5 mg/dL, respectively.

Polyamine transport by mammalian cells and mitochondria: role of antizyme and glycosaminoglycans.

The role of antizyme (AZ) and glycosaminoglycans in polyamine uptake by mammalian cells and mitochondria was examined using NIH3T3 and FM3A cells and rat liver mitochondria. AZ is synthesized as two isoforms (29 and 24.5 kDa) due to the existence of two initiation codon AUGs in the AZ mRNA. Most AZ existed as the 24.5-kDa form translatable from the second AUG, but a portion of the 29-kDa AZ from the first AUG was associated with mitochondria because of the presence of a mitochondrial targeting signal between the first and the second methionine. The predominance of the 24.5-kDa isoform was mainly due to the presence of spermidine and a favorable sequence context (Kozak sequence) at the second initiation codon AUG. Spermine uptake by NIH3T3 cells was inhibited by both 29- and 24.5-kDa AZs, but uptake by rat liver mitochondria was not influenced by either form of AZ. Because spermine uptake by mitochondria caused a release of cytochrome c, an enhancer of apoptosis, we looked for inhibitors of mitochondrial spermine uptake other than AZ. Cations such as Na+, K+, and Mg2+ were inhibitors of the mitochondrial uptake. It has been reported that heparan sulfate on glypican-1 plays important roles in spermine uptake by human embryonic lung fibroblasts. Heparin, but not heparan sulfate, slightly inhibited spermine uptake by FM3A cells in the absence of Mg2+ and Ca2+ but had no effect under physiological conditions in the presence of Mg2+ and Ca2+.

Optimal administration dosage of magnesium sulfate for torsades de pointes in children with long QT syndrome.

BACKGROUND: Intravenous administration of magnesium sulphate (MgSO(4)) is a very effective and safe treatment for torsades de pointes (TdP) associated with acquired long QT syndrome (LQTS) in adults. Discussed here is the efficacy of MgSO(4) for TdP in children with congenital and acquired LQTS. METHODS: The optimal MgSO(4) dosage and serum magnesium (SMg) was determined in six consecutive children with TdP; four had congenital LQTS and two had acquired LQTS. A bolus injection of MgSO(4) was given intravenously over 1 to 2 minutes followed by continuous infusion for the next 2 to 7 days. RESULTS: Of the six patients, five responded completely to the initial bolus of 6.1 +/- 4.2 mg/kg (range, 2.3-12 mg/kg). One (a neonate with congenital LQTS) required a total of 30 mg/kg until complete TdP elimination. Continuous infusion was given at rates of 0.3 to 1.0 mg/kg/hr with no recurrence of TdP. SMg concentration was 3.9 +/- 1.0 mg/dL (2.9-5.4 mg/dL) immediately after bolus injection. CONCLUSION: Intravenous MgSO(4) infusion effectively treated TdP in children with LQTS. Optimal bolus dosage, infusion rates and SMg concentration were 3 to 12 mg/kg, 0.5 to 1.0 mg/kg/hr and 3 to 5 mg/dL, respectively.