Hypoplastic left heart syndrome has been considered to be one of the most challenging congenital heart diseases with a high mortality. Early postoperative mortality after the first stage intervention has dramatically improved due to advances in perioperative management and surgical technique. Nonetheless, mid- and long-term mortality and morbidity are still suboptimal, and improvement of quality of life including neurodevelopmental outcome remains to be accomplished. This syndrome has both intrinsic and acquired cardiovascular functional abnormalities, constructing a complex pathophysiology that needs to be understood. In this review, we summarize and discuss cardiovascular pathophysiological characteristics inherent to this unique syndrome.

Advances in medicine have improved the outcomes for children with chronic diseases, and most children with special healthcare needs enter adulthood. Many, however, still require medical care for their chronic conditions, sequelae, and complications. The goal of transitional care is to maximize lifelong functioning and potential through the provision of high-quality, developmentally appropriate healthcare services that continue uninterrupted even when the individual moves from adolescence to adulthood. To achieve this goal, it is necessary for such individuals to start training for their own health management in adolescence or even earlier if possible. Checklists, which are tailored to patient age and intelligence, are valuable for disease comprehension. It is also important to support patient in any education and employment problems that they may face. Transition in patients with congenital heart disease has been a step ahead of those in other diseases. It is important to promote progress in transitional care not only in cardiology but also in other specialties in our country.

Mitochondrial cardiomyopathy is characterized by an oxidative phosphorylation (OXPHOS) disorder due to genetic mutations in genes encoding the structure and function of myocardial mitochondria. Mutations in both mitochondrial and nuclear DNA can cause mitochondrial cardiomyopathy, and it is typically recognized as one of the generalized manifestations of neurological and metabolic disorders. Cardiomyopathy, however, can be the only phenotype of mitochondrial disease and is often misdiagnosed. Cardiac manifestations vary from asymptomatic to catastrophic heart failure or sudden death. Although recent evolution in genetic tests has allowed the identification of the causative gene, tissue sampling to identify an OXPHOS disorder is still regarded as the gold standard for diagnosis.

Pulmonary arterial hypertension (PAH) is a crucial determinant of morbidity and mortality in children and adults. It can present at any age from infancy to adulthood. The clinical features of pediatric PAH, however, differ from those of adults, and in children, there is a predominance of idiopathic PAH (IPAH) or that associated with congenital heart disease (CHD). Without appropriate treatment, the median survival rate after diagnosis of IPAH in children is considerably worse than that in adults. Additionally, though PAH related to CHD in most children may resolve after surgical correction, some children may develop an irreversible pulmonary vascular disease. Recent studies of pediatric PAH have highlighted the unique aspects of pathogenesis and challenging treatments in IPAH or PAH associated with CHD. Treatment with new selective pulmonary vasodilators offers hemodynamic and functional improvement in pediatric populations. Survival within the first 5 years following diagnosis has been reported to be between 62％ and 90％, and the survival rate has been similar between IPAH and PAH associated with CHD. However, there is currently limited data from randomized controlled trials in children with PAH for evaluating the safety and efficacy of vasodilator therapies, which are approved for adult patients. Therefore, further studies are required for development of specific strategies for treating children with PAH. This review provides a brief overview of recent information regarding current approaches to PAH in children.

Background: The number of patients with trisomy 18 undergoing cardiac surgery has recently been increasing. In our institute, the primary purpose of treatment in patients with trisomy 18 is to facilitate discharge and cardiac surgery has not yet been performed in such cases. In the present report, we reviewed patients treated at our institute to demonstrate the prognosis of patients with trisomy 18 without cardiac surgery.

Methods: We collected detailed clinical information from the medical records of 17 patients with trisomy 18 from April 2005 to December 2015. We retrospectively studied the neonatal condition, survival rate, and cause of death. We also reviewed patients with a high pulmonary flow, the large left-to-right shunt (LS) group, who were at a potential risk of heart failure.

Results: All patients had congenital heart disease (CHD). The 1-year survival rate was 64.7%, with 70.6% of patients discharged at a median age of 129 days (range, 16–285 days). The median survival time of patients who died during the present study was 104.5 days (range, 0–1,054 days). In the LS group, 62.5% of patients survived for one year with no evidence of heart failure. Two patients in the LS group died in hospital from heart failure.

Conclusions: Favorable survival was achieved through standard neonatal intensive treatment without cardiac surgery. Patients with trisomy 18 complicated by CHD with a high pulmonary flow should be maintained in a stable condition without cardiac surgery due to persistent pulmonary hypertension resulting from vascular abnormalities. Further studies are required to evaluate the long-term effectiveness of cardiac surgery for patients with trisomy 18.

Isolated unilateral pulmonary venous atresia (PVA) is an extremely rare anomaly that typically presents with hemoptysis and pneumonia; however, the most appropriate management strategy remains controversial due to the high variability in clinical course between cases. Herein, we present three cases and discuss the diagnostic and therapeutic considerations.

Case 1: A 4-year-old girl presented with a history of recurrent hemoptysis and pneumonia since 18 months of age. Lung perfusion scintigraphy demonstrated decrease in the right pulmonary blood flow. Pulmonary arterial wedge angiography (PAWA) identified a right PVA. The patient underwent pulmonary vein reconstruction using a sutureless technique.

Case 2: A 4-year-old girl was referred due to hemoptysis. Lung perfusion scintigraphy demonstrated a decrease in left pulmonary blood flow, and the diagnosis was confirmed by PAWA. We abandoned the repair in this case due the presence of a long gap between the left pulmonary vein and left atrium.

Case 3: A 36-year-old female presented with a history of recurrent hemoptysis and pneumonia from infancy. PVA was suspected according to the results of lung perfusion scintigraphy, and the diagnosis was confirmed by PAWA. We abandoned the repair in this case as the development of pulmonary arterial obstructive disease was expected.

If lung perfusion scintigraphy demonstrates a remarkable reduction in unilateral pulmonary blood flow, PVA should be suspected and PAWA should be performed to confirm the diagnosis. Pulmonary vein reconstruction represents a treatment option in cases where the diagnosis is made in early childhood and anatomical repair is feasible. For right PVA, the sutureless technique is considered to be effective in preventing postoperative pulmonary venous stenosis.

It is well known that exercise, mental excitement, and stress induce torsade de pointes (TdP) in congenital long QT syndrome (LQTS). The excitability of the sympathetic neuron is believed to be deeply involved especially in LQT1 and LQT2. Therefore, beta blockers are the first-line drugs considered to prevent TdP, but in some cases, continuing medication is difficult because of internal medication compliance issues. The patient was a 14-year-old girl who had no apparent family history of LQTS, sudden death, or fainting, but had repeated syncopal attacks after starting elementary school. Long QT was identified in a school health examination, and the patient was referred to our hospital. She was diagnosed as having long QT syndrome (LQT2) on the basis of genetic screening results. Βeta blocker was administered to prevent attacks. Over time, no syncopal attacks occurred, but she suspended her own treatment at age 10 years because of reduced exercise tolerability. She returned to our hospital as an outpatient at age 13 years because of repeated syncopal attacks and received beta blocker and exercise restrictions. The syncopal attacks ceased, but the patient became mentally unstable and stopped attending school. Moreover, she had palmar hyperhidrosis in both hands. At age 14 years, she was performed endoscopic thoracic sympathectomy (ETS). The palmar hyperhidrosis improved, and no side effects such as compensatory hyperhidrosis or Horner’s syndrome were observed. Moreover, the corrected QT when resting improved from 570 to 511 ms.

We report two cases of coronary aneurysms that were not previously diagnosed during acute illness but were discovered for the first time during school cardiac screening (SCS).

Case 1 was a 6-year-old boy who had successful immunoglobulin treatment for typical Kawasaki disease (KD) at the age of 3. Though an echocardiographic examination during acute phase was reported as normal, echocardiography at SCS demonstrated giant left coronary aneurysms separated by coronary artery stenosis. Consequently, the patient was placed on oral warfarin and underwent percutaneous coronary angioplasty and coronary artery bypass surgery.

Case 2 was a 13-year-old boy who had a 9-day history of fever with several signs of KD and had been receiving treatment for juvenile idiopathic arthritis at 9 years of age. Though an echocardiographic examination at 9 day of the illness was reported as normal, echocardiography at SCS demonstrated a moderate sized left coronary artery aneurysm that was thought to be a sequela of incomplete KD. Consequently, the patient was administered oral aspirin and was regularly followed-up.

These cases illustrates that SCS may present an important opportunity to diagnose coronary aneurysm in patients with a history of complete or incomplete KD. As the presence of coronary aneurysms significantly alters treatment and prognosis, guidelines for echocardiography quality control and the proper timing of echocardiography in patients with incomplete KD are required.