Background: Atrioventricular valve regurgitation (AVVR) has a notable impact on the prognosis of patients with hypoplastic left heart syndrome (HLHS) and right atrial isomerism (RAI).

Methods: The study population comprised two groups: (1) HLHS and RAI group: n=32 (HLHS=15, RAI=17), and (2) normal control group: n=53. X-plane images of apical four-chamber view and orthogonal plane cutting through the center of annulus were acquired using transthoracic matrix array probe. Speckle-tracking of the two opposing points on the annulus in four-chamber plane and orthogonal plane was performed, and the distances of respective opposing points were consecutively measured along the cardiac cycle. Atrioventricular valve (AVV) area dynamics were classified into three categories according to the areal change pattern during systole in the normal group: Type-1: area decreases during systole; Type-2: area increases during systole; and Type-3: no significant areal change. The HLHS and RAI groups were subdivided into two subgroups according to the grade of AVVR: low-grade AVVR and high-grade AVVR, and the annular dynamics were compared between the groups.

Results: Normal group was classified into the subgroups as follows: Type-1=22 (42%); Type-2=24 (45%); and Type-3=7 (13%). HLHS and RAI group was classified into the following subgroups: Type-1=4 (13%), Type-2=7 (24%), and Type-3=21 (65%). Type-3 was predominant in the HLHS and RAI groups (p<0.01). The subdivided groups were similarly classified into low-grade AVVR group (n=16) and high-grade AVVR group (n=16). Type-3 was predominant in the high-grade AVVR group (p<0.01).

Conclusions: In patients with single ventricle associated with tricuspid valve or common AVV, significant valve incompetence was observed in those with reduced annular dynamics, suggesting the importance of annular function in the patients.

A six-year-old boy was admitted to our institute because of syncope and exercise intolerance. Cardiac catheterization revealed elevated pulmonary arterial pressure of 89/35(65) mmHg and elevated pulmonary vascular resistance index of 14.4 Woods units·m². We diagnosed severe primary pulmonary hypertension with right heart failure. Since no effective therapy for pulmonary hypertension was established then, we could not treat him effectively. However, his trans-tricuspid pressure gradient on echocardiogram gradually decreased without therapy and he became asymptomatic when he reached junior high school. He did not visit our outpatient clinic after he started college because of commitments at work. When admitted to our hospital at the age of 28, cardiac catheterization showed that his pulmonary arterial pressure and pulmonary vascular resistance index had decreased to 50/18(32) mmHg and 7.8 Woods units·m², respectively. He had frequent nasal bleeding and we found one telangiectasia spot on his foot. His genetic analysis revealed an ALK-1 mutation and he was diagnosed with heritable pulmonary arterial hypertension. Pediatric heritable pulmonary arterial hypertension with ALK-1 mutation is usually progressive and has poor prognosis. However, this may not be always true, as demonstrated by our case.

We describe the case of an isolated left common carotid artery arising from the main pulmonary artery in association with a right aortic arch and an anomalous origin of the left subclavian artery. The infant underwent pulmonary artery banding together with ligation of the right patent ductus arteriosus and the aberrant left common carotid artery.

Propionic acidemia is a congenital metabolic disorder that typically develops in the neonatal period, with a metabolic crisis comprising metabolic acidosis and hyperammonemia. However, late-onset cardiomyopathy is an initial presentation in a limited number of patients. The present case was a 14-year-old female with mental retardation and epilepsy. During a cardiac screening test conducted in school, tachycardia was observed, and a diagnosis of dilated cardiomyopathy was reached. The acylcarnitine analysis showed a high level of propionylcarnitine; thus, propionic acidemia was strongly suspected. Genetic analysis identified compound heterozygous mutations in the PCCB gene. Myocardial biopsy showed hypertrophy of cardiomyocytes with vacuolar changes under light microscopy, and the number of mitochondria was increased under electron microscopy. When differentiating cardiomyopathy in children and adolescents, physicians should be aware of the possibility of inborn errors of metabolism as a cause.

We diagnosed Barth syndrome with tafazzin (TAZ) variants associated with left ventricular noncompaction cardiomyopathy (LVNC) in a 1-month-old male infant, weighting 3,010 g, born at 40 weeks of gestation. At 14 days of age, the infant presented with cyanosis while crying and was referred to our institution at 1 month of age. Echocardiography revealed that the left ventricular wall was highly trabeculated, with a ratio of noncompacted to compacted myocardium of >2.0 in all segments. At 4 months of age, the patient developed a urinary tract infection and heart failure. Laboratory findings showed neutropenia and an elevated B-type natriuretic peptide level at 207 pg/mL. After admission, he was initially treated with antibiotics, inotropes, and diuretic agents which alleviated the infection and heart failure. Genetic analyses confirmed that the patient and his mother had a TAZ variant, c.461-2A>C, confirming the diagnosis of Barth syndrome. At 2 months of age, the patient showed preserved global circumferential strain but decreased global longitudinal strain on a layer-specific two-dimensional speckle tracking echocardiography. At 9 months of age, both global circumferential and longitudinal strain had decreased, and cardiac rotation showed that both the cardiac base and apex had rotated counterclockwise. The patient died at 12 months of age due to progressive heart failure induced by dilated cardiomyopathy with LVNC. This case suggests the impact of the dilated cardiomyopathy phenotype with LVNC and emphasizes the clinical advantages of estimating cardiac performance using two-dimensional speckle tracking echocardiography in LVNC patients with TAZ variants.

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.

Neonatal myocarditis is most often caused by enterovirus and has a high mortality of >50%. We report a case of neonatal enterovirus myocarditis. The patient was born at term with a birth weight of 2,637 g. He developed fever on perinatal day 2, and a gallop rhythm was detected by auscultation on day 7. Based on severe left ventricular dysfunction and elevated troponin T, the diagnosis of acute myocarditis was made. Despite inotropic support, his cardiovascular condition deteriorated. He was transferred to a tertiary medical center on day 9 and was further treated with inotropes and mechanical ventilation. On day 30, he was weaned from hemodynamic support and transferred back to the local hospital. Enterovirus was detected in the blood sample taken on day 10 and was thought to be the cause of myocarditis. The test result for neutralizing antibody was negative. Prevention of viral infection during the perinatal period is crucial, given the severity of the disease, requirement of intensive care, and limited treatment options currently available.