Department of Pediatric Cardiology
Target disease,treatment
Target diseases
Congenital heart diseases in childhood
Today, over 95% of patients with congenital heart diseases survive thanks to advanced heart surgery, intensive care for neonates and infants, and the development of new catheter-based treatment techniques, among others. For 38 years since the establishment of the department, we have provided internist diagnosis and performed surgical procedures for many patients with congenital heart diseases that are extremely difficult to treat. The number of cases treated and the positive outcomes achieved place us among the top medical institutions not only within Japan but in the world. The number of cases for which we have performed catheterization is the highest in Japan.
Adult congenital heart diseases
It has become possible for many patients with congenital heart diseases to reach adulthood after undergoing surgery in childhood. These adult patients require medical attention for postoperative symptoms as well the prevention and management of lifestyle-related diseases, which begin to appear as they age. We are among the largest medical facilities in the country that treat adult patients with congenital heart diseases, performing pathological evaluation, catheterization, subsequent surgery, and prepregnancy examination for female patients, among other approaches.
Examination following school medical checkups for diagnosis and management of cardiac murmur, abnormalities detected on electrocardiography, and arrhythmia, among others
We conduct detailed examination of children in whom abnormalities are detected during medical checkups at schools primarily in the Hokusetsu area. We contribute to the prevention of cardiac accidents by detecting heart diseases that can be identified in school-age children based on interviews with patients, detection of cardiac murmurs, and electrocardiography findings, among others, and by providing health guidance via schools and appropriate medical care at the hospital.
Myocardial diseases (cardiomyopathy and myocarditis)
Cardiomyopathy is a disease caused by an abnormality in the heart muscle, which is congenital in most cases. Its major types include hypertrophic, dilated, and constrictive cardiomyopathies. Myocarditis is an acute disease primarily caused by a viral infection and characterized by severe damage to cardiac muscle cells. In treating these diseases, we conduct a battery of tests to determine each patient's condition with maximum accuracy, providing care supplemented with appropriate pharmacotherapy to prevent heart failure.
Coronary artery sequelae of Kawasaki disease (diagnosis and management, coronary artery bypass surgery)
We have provided life-saving treatment, with carefully designed antithrombotic therapy and circulation management, to many patients with Kawasaki disease who developed coronary artery aneurysm and exhibited resistance to acute-phase treatment, such as immunoglobulin therapy. We have, in fact, performed coronary artery bypass surgery on the largest number of children with Kawasaki disease in the world.
Arrhythmias in children
Drawing on our abundant clinical experience, we have appropriately diagnosed patients with Wolff-Parkinson-White syndrome (often detected during school medical checkups) and complex cases of arrhythmia (observed following surgical interventions for congenital cardiac diseases). We have provided these cases with treatments that were tailored for each patient, including pharmacotherapy, catheter ablation, and pacemaker implantation.
Pulmonary circulation disease (mainly treatment of pulmonary arterial hypertension)
We conduct the diagnosis and treatment of pulmonary circulation diseases in children, including idiopathic and hereditary pulmonary arterial hypertension, pulmonary arterial hypertension associated with congenital cardiac diseases, and pulmonary aneurysm. With the development of new effective drugs in succession, the condition and prognosis of patients with these ailments have considerably improved recently.
Severe heart failure (implantation and management of left ventricular assist device and heart transplantation)
When patients begin to suffer from severe heart failure caused by primary illnesses, such as congenital heart diseases, cardiomyopathy, congenital metabolic disorders, or neuromuscular disease, and the available pharmacotherapies are not improving their cardiac function, we opt for the implantation of a left ventricular assist device (Berlin Heart for children) or initiate steps to perform heart transplantation. We are one of the three facilities in Japan that are authorized to perform ventricular assist device implantation and heart transplantation in children.
Diagnostic methods
The heart is a pump-like organ whose muscles contract rhythmically to electrical stimuli, using the force thus produced to supply blood to the entire body. Therefore, to determine whether the heart is functioning well, it is essential to determine the following:
- Whether the heart is free of structural abnormalities;
- Whether the rhythms of heart contraction are normal; and
- Whether the heart muscles are contracting normally to supply sufficient blood to the whole body.
Tests and diagnostic methods for congenital heart diseases, arrhythmia, myocardial diseases, etc.
- Electrocardiography
It records electrical signals generated in the heart to examine cardiac rhythms and their burden on each heart chamber. - Echocardiography
It allows the diagnosis of abnormalities in the structure of the heart, the shape and movement of the valves, and the contraction of the heart, among others. - Transesophageal echocardiography
This modality involves inserting a tube with a camera, resembling that used for gastroscopy, from the mouth for a detailed observation of the internal portion of the heart. - Master test (a two-step exercise test)
It involves walking up and down a two-step stairway to examine changes in cardiac rhythms and echocardiographic waves with exercise. - Electrocardiography treadmill test
It involves running on a belt conveyor-like apparatus with electrocardiography electrodes attached to the chest. - Multislice computed tomography
This modality generates three-dimensional images of the great vessels of the heart after the injection of a contrast medium. - Magnetic resonance imaging
This modality allows the examination of soft tissues of the body using a scanner that generates a strong magnetic field. - Nuclear medicine examination
It involves intravenous injection of a pharmaceutical drug containing a weak radioisotope; the signals are captured with a detector that generates images, allowing the examination of the morphology, function, and metabolism, among others, of various organs. - Cardiac catheterization
It involves inserting a thin tube, i.e., a catheter, via an artery to reach the heart for measuring blood pressure and oxygen saturation, allowing scientific analysis of the condition of the heart and lungs. At the end of the procedure, a contrast medium is infused from the tip of the catheter to generate X-ray images for definitive diagnosis of diseases involving the heart and great vessels. - Blood tests
Brain natriuretic peptide is an important indicator of heart failure.
Blood coagulation tests are essential for patients who have undergone surgery previously for the implantation of artificial heart valves or have undergone the Fontan procedure.
Anemia can increase the burden on the heart and must be evaluated by periodic testing.
Treatment methods
Catheterization for congenital heart diseases
- Atrial septal defect
In patients with atrial septal defect, the right atrium and ventricle become dilated due to left-to-right shunt, with blood flowing through the defective septum. Atrial septal defect is asymptomatic in childhood, but if left untreated, patients aged >40 years can begin experiencing atrial fibrillation and other forms of arrhythmia, blood flow congestion, edema and fatigue due to pulmonary hypertension, and other symptoms of right-sided heart failure. In most cases, if the defect is treated in childhood, cardiac dilatation disappears and arrhythmia does not occur. - Patent ductus arteriosus
In patients with this condition, the ductus arteriosus, the fetal blood vessel which normally closes within a few days of birth, remains open, causing a left-to-right shunting of the blood flow. Subsequently, the left atrium and ventricle become dilated, and symptoms of left-sided heart failure, including tachypnea and poor growth, can appear. Even in cases where the opening is narrow, the risk of infective endocarditis is present. In early infancy, the ductus arteriosus is surgically closed by ligation, whereas in and after late infancy, catheter-based closing is adopted. - Aortic coarctation
Among patients with this condition, i.e., narrowing of the aorta, the closure of the ductus arteriosus in affected neonates leads to shock due to left ventricular dysfunction, requiring emergency surgery. In cases where aortic coarctation is detected later, hypertension in the upper half of the body becomes problematic. Blood pressure further rises during physical exercise, leading to intracranial hemorrhage in rare cases. For primary school-age and older patients, we primarily perform percutaneous stenting. - Hypoplastic left heart syndrome
This is one of the most severe congenital heart diseases. Recently, many cases have been detected based on fetal ultrasound findings. Patients with a favorable condition receive a three-stage surgical treatment: Norwood procedure at the age of 1 month, bidirectional Glenn procedure after the infant becomes capable of head control, and the Fontan procedure after the infant begins walking. Using beta-adrenergic blocking agents, vasodilators, and nasal oxygen inhalation, we aim to enable patients to attend school (or kindergarten) in good spirits. - Asplenia syndrome
In patients with this syndrome, the organs in the body develop on the right side. The cardiovascular structure of these patients is complex and diverse, with manifestations of univentricular circulation, such as atrioventricularis communis, double-outlet right ventricle, and pulmonary stenosis. The survival rate is lower in the presence of complications such as total anomalous pulmonary venous return accompanied with stenosis and severe atrioventricular valve reverse flow. Patients can also present with gall bladder and bile duct abnormalities, intestinal malrotation, or a physical constitution that increases susceptibility to bacterial infections.
Treatment for arrhythmia
At the Department of Pediatric Cardiology, we treat arrhythmia in children and adult patients with congenital heart diseases, including organic heart diseases and channelopathies.
The treatment methods usually adopted include the following:
- Pacemaker implantation
- Administration of antiarrhythmic medication
- Catheterization (catheter ablation)
We have so far evaluated approximately 400 patients, for whom pacemaker implantation was subsequently performed, and performed catheter-based treatment and examination in 300 patients. We have treated 130-140 patients with channelopathies, including long QT syndrome in children and catecholaminergic polymorphic ventricular tachycardia. In each patient, we first identify the cause of arrhythmia, eliminating or otherwise alleviating it to reduce the burden on the heart, while caring for bradycardia and tachycardia.
last updated : 2021/10/01