Although treatment for hypoplastic left heart syndrome has improved, this condition is still considered high-risk.

[Aortic reconstruction] Aortic stenosis causes postoperative heart failure by increasing afterload and thus pulmonary blood flow. Patch augmentation of the entire arch is a common reconstruction technique for creating a large flow path. In Japan, however, reconstruction with primarily autologous tissue is common.

[Pulmonary artery reconstruction] The pulmonary blood flow must be adequate. Excessive pulmonary blood flow causes cardiac volume overload, while insufficient blood flow results in hypoxemia. A right ventricular-pulmonary artery conduit provides hemodynamic stability. This is considered an option, particularly for patients with a poor preoperative condition, such as low cardiac function or tricuspid valve regurgitation. However, there are concerns about the right ventricular incision, which can lead to ventricular dysfunction, and conduit stenosis.

[Bilateral pulmonary artery banding] Many Japanese institutions perform bilateral pulmonary artery banding as the first palliative procedure. It significantly reduces the risk of low birth weight, prematurity, cerebral hemorrhage, and complications of early cardiopulmonary bypass. It is expected to improve long-term outcomes, including neurodevelopment, by postponing open chest surgery during the neonatal period.

[Extracorporeal circulation] Partial cerebral perfusion is widely used in Japan. Complete circulatory arrest by hypothermia is most commonly used in North America and Europe, though the number of such procedures has grown in recent years. Lower body perfusion is also commonly used in Japan, but it has not become the standard method in other countries. Lower body blood perfusion is expected to reduce renal failure and shorten the intensive care unit stay.

Kawasaki disease is an acute systemic vasculitis syndrome that primarily affects childdren, but the long-term remote effects of systemic vasculitis beyond coronary complications are unknown. Is a history of Kawasaki disease a true risk factor for future vascular complications like atherosclerosis? Unfortunately, there is insufficient evidence to answer this question. However, based on my own experience in blood vessel and inflammation research, I attempted to review the significance of the research results findings to date on Kawasaki disease vasculitis, as well as the limitations of research methods, in the hope of providing new perspectives for the next generation of researchers.

Catheterization for adult congenital heart disease (ACHD) is rapidly progressing. In Japan, the number of ACHD patients has far outpaced that of pediatric patients, and the need for catheterization for ACHD is growing. In particular, catheterization is a useful tool for long-term postoperative structural problems for which effective medical therapy is limited. It can lower the risk of repeat open heart surgery while also providing minimally invasive treatment. This paper discusses catheterization procedures that are well-established in Japan, such as ASD closure and PDA closure, as well as those that are likely to be introduced in Japan in the future, such as transcatheter correction of superior sinus venosus atrial septal defects.

Brugada syndrome (BrS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) are inherited cardiac disorders with distinct electrocardiographic findings and lethal ventricular arrhythmias. BrS is primarily associated with loss-of-function SCN5A variants, which cause repolarization abnormalities such as coved-type ST elevation based on transmural action potential gradient in the right ventricular outflow tract (RVOT). Fibrosis on the epicardial side of RVOT, as well as abnormalities of the gap junction provide the arrhythmogenic substrate and cause depolarization abnormalities. BrS typically appears in middle age and is 8–10 times more common in males. Although testosterone is thought to cause male predominance, estrogen may act as a protective factor in female BrS. ARVC is predominantly induced by abnormalities in desmosome-related genes, which disrupt intercellular adhesion and the Wnt/β-catenin pathway, leading to the replacement of cardiomyocytes with fibro-fatty tissues. This abnormality causes electrocardiographic findings like ε-waves and negative T waves in the right precordial leads. ARVC with right ventricular involvement is diagnosed using revised Task Force criteria, whereas arrhythmogenic cardiomyopathy (ACM) with left ventricular or biventricular involvement is diagnosed using Padua criteria. BrS and ARVC are uncommon in children, but the frequency of lethal ventricular arrhythmias is higher than in adult patients. Additional research is required to determine risk stratification and treatment options for pediatric patients.

Congenital heart disease occurs in 5 to 10 out of every 1000 live births and has a significant impact on mortality risk throughout life. Although most cases are due to multifactorial inheritance, some appear to be caused by a chromosomal abnormality or congenital anomaly syndrome, implying that specific genes within impaired chromosomes are to blame. Recent advances in molecular genetics have allowed for the identification of genes in critical genomic regions of chromosomal abnormality that may be at the root of congenital heart diseases, as well as the clarification of molecular pathways in cardiovascular development. The current article examines the clinical characteristics and genetics of chromosomal abnormalities associated with congenital heart diseases that are frequently detected by pediatric cardiologists during genetic examinations covered by National Health Insurance.

There are few reports on early physiotherapy for critically ill pediatric patients and extracorporeal membrane oxygenation in Japan due to concerns about medical device removal by accident. We present a safe method of early physiotherapy during extracorporeal membrane oxygenation with neck cannulation, as well as the treatment plan. The patient was a 2-year-old boy weighing 14.3 kg with no medical history. He had symptoms of tachypnea and severe tachycardia, so tachycardia-induced cardiomyopathy was diagnosed. On the 2nd day of hospitalization, the heart failure worsened, resulting in low cardiac output syndrome and requiring extracorporeal membrane oxygenation. Physiotherapy, which included range of motion exercises, respiratory physiotherapy, and postural drainage, began on the same day as extracorporeal membrane oxygenation; it was ensured that the neck cannulation insertion angle, drainage pressure, and blood flow were not changed using a handmade wedged-shape urethane cushion. Extracorporeal membrane oxygenation was removed on the 4th day of hospitalization, and there were no complications during the initial physiotherapy. The patient was extubated on the 11th day of hospitalization and discharged on the 14th hospitalization day. Early physiotherapy during extracorporeal membrane oxygenation could be performed safely in a pediatric patient with acute or severe heart failure by ensuring the neck cannulation insertion angle and neck position.