This review examines the natural-colored, cross-sectional morphology of the foramen ovale (FO), ductus venosus (DV), right ventricle (RV), and pulmonary artery (PA) in fetal and neonatal rats. The ductus arteriosus (DA) and congenital heart disease are reviewed separately. The in situ cross-sectional morphology of fetal and neonatal rat hearts was studied by rapid whole-body freezing, slicing on a freezing microtome, and serially photographing the cross-sections every 0.5 mm with a stereoscopic microscope (Wild M400). The serial frontal sections of the fetal thorax and upper abdomen showed the fetal oxygenated blood route including the umbilical vein, DV, inferior vena cava, posterior right atrium, FO, and left atrium. Neonatal frontal sections of the same area revealed closure of the DV, FO, and DA, in addition to rapid enlargement of the peripheral pulmonary vessels. Neonatal closure of the FO was associated with remarkable growth of the atrial septum flap. The fetal atrial septum was short and thin at the FO, and the flap tip only just reached the rim of the FO. Neonatally, this atrial septum grew rapidly in length and thickness within two days, closing the FO.

Among the cardiac implantable electrical devices used in pediatric cardiology, a pacemaker (PM) is mainly used rather than an implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT). For pediatric patients without a congenital heart disease (CHD), epicardial leads are commonly used because of the small body size. The most common indication for using a PM is congenital complete atrioventricular block (CCAVB). ICD implantation in patients who weigh ＜30 kg, mainly those with long QT syndrome or hypertrophic cardiomyopathy, shock leads are required to be implanted in a different manner than those in other adults. CRT is assumed to be effective in patients with left ventricular conduction delay and dyssynchrony, chiefly in those with CCAVB or cardiomyopathy. For CHD patients, epicardial leads are selected for those with limited venous access to the heart or the intracardiac shunt. PM implantation is considered based on the anatomy, operative procedure, and hemodynamics. The PM timing needs to be set while assessing the hemodynamics because it has a considerable impact on the hemodynamics of CHD patients. The indication for the use of ICD for the primary prevention of sudden cardiac death in CHD has not been established yet owing to the heterogeneous cardiac anatomy and lack of randomized clinical trials. For CRT, the pacing lead positions should be decided according to the ventricular morphology and the patterns of ventricular dyssynchrony.

Background: In patients with a functional single-ventricle, coil embolization is commonly performed to avoid complications after the Fontan procedure. The position for coil embolization should be determined after considering the postoperative changes in the aortopulmonary collateral arteries (APCAs).

Methods: The study involved 163 patients who underwent the Fontan procedure between 2009 and 2015. The amount of APCA was assessed using a 3-point scale based on the aortogram in the cardiac catheterization. The total score for the five sites (bilateral internal thoracic artery, bilateral subclavian artery, and descending aorta) was calculated and compared in patients with and without coil embolization and before and after the Fontan procedure.

Results: The mean scores for the APCAs ranged from 6.1±1.5 to 4.5±1.8 points in patients with coil embolization (＋) and from 4.4±1.7 to 3.6±1.7 points in those without coil embolization (−), indicating a significant decrease. The scores of 35 patients at ≥5 years after the Fontan procedure had decreased as compared to those at 6 months postoperatively (mean 4.2±2.0 to 1.3±1.2 points). The APCA flow of 30 patients measured using a magnetic resonance imaging similarly decreased after the Fontan procedure (mean 1.4±0.6 to 0.8±0.6 L/min). When APCA scores before the Fontan procedure were ≤5 points, there were no significant differences between the coil embolization (＋) and coil embolization (−) groups as to the incidence of prolonged pleural effusion.

Conclusion: After the Fontan procedure, the APCA tended to decrease with or without coil embolization. Routine coil embolization is not necessary, which is indicated only when APCA scores are ≥6 points.

Background: Pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) is a risk factor of right ventricular (RV) dysfunction and arrhythmia. The aim of this study was to evaluate the mid-term outcome of pulmonary valve replacement (PVR) using bioprosthetic valves in adult patients with PR after a TOF repair.

Method: A total of 32 patients with repaired TOF, who underwent PVR in our hospital between April 2003 and March 2017, were retrospectively examined. The mean follow-up duration after the PVR was 5.4±4.2 years. Decision regarding the surgery was made on the basis of clinical symptoms, electrocardiography results, chest radiography, echocardiography findings, magnetic resonance imaging results, and cardiac catheter examination findings.

Results: There was no perioperative mortality or the need for re-intervention after PVR. A patient underwent Bentall operation 3 years after PVR. RV end-diastolic volume index (RVEDVI) was significantly reduced (176.3±57.2 mL/m² before to 108.1±19.4 mL/m² after PVR, p＜0.05). There was no difference in the RV ejection fraction (42.7％±8.49％ before and 42.4％±7.94％ after PVR, p＞0.05). The left ventricular (LV) ejection fraction of RVEDVI group was ＜160 mL/m², which showed an improvement; however, there was no significant statistical difference (55.3％±8.03％ before and 58.5％±4.95％ after PVR, p＝0.12). It was significantly higher in postoperative left ventricular end-diastolic pressure (LVEDP) (15.2±2.78 mmHg) of RVEDVI ≥160 mL/m² group than postoperative LVEDP (11.2±2.81 mmHg) of RVEDVI ＜160 mL/m² group (p＜0.05).

Conclusion: PVR after TOF repair in adult patients with PR is effective and involves a low risk of mortality. It is suggested that 160 mL/m² of RVEDVI would be valid for determining whether surgery is indicated for the maintenance of RV and LV functions.

Four-dimensional flow magnetic resonance imaging (4D flow MRI) visualizes three-dimensional pulsatile blood flow and allows quantification of the mechanical stress to the cardiovascular system. We report a case of total cavopulmonary connection (TCPC) with a kinked extracardiac conduit in a 14-year-old boy with protein-losing enteropathy (PLE), for which a 4D flow MRI assessment of hemodynamics proved useful. Aged 2 years, the patient underwent extracardiac TCPC with an 18-mm expanded polytetrafluoroethylene conduit for a single right ventricle and pulmonary atresia. He developed PLE 3 years later, which was controlled with steroids. Aged 14 years, computed tomography revealed a kinked conduit with calcification. Cardiac catheterization showed no drop in pressure in the kinked portion, but the mean pulmonary arterial and right ventricular end-diastolic pressures were elevated. A systemic right ventricular pressure curve demonstrated a slow pressure decrease in the isovolumic relaxation phase, with a prolonged time constant, and 4D flow MRI demonstrated no flow acceleration through the kinked portion or in the systemic ventricle, with sufficient low-flow energy loss. We decided initially to optimize the patient’s medication to improve diastolic dysfunction, and then to perform a conduit exchange in the future once the steroid dose was reduced.

Reconstruction of the left superior vena cava (LSVC) is required in biventricular repair when the LSVC drains directly into the left atrium. However, the criteria for reconstruction and a standard method have not been established. We report a case of successful concomitant intra-cardiac repair and LSVC reconstruction using the right atrial wall flap. A 10-month-old girl with a common atrium, an incomplete atrioventricular septal defect, left atrioventricular valve regurgitation, and patent ductus arteriosus presented with severe cyanosis and heart failure. Preoperative angiography showed each superior vena cava (SVC) draining directly into the ipsilateral atrium, with the LSVC larger than the right SVC. With balloon catheter occlusion of the LSVC, the pressure in the LSVC increased from 6 mmHg to 38 mmHg, so simple ligation of the LSVC was considered to be high risk. After intra-cardiac repair, the posterior wall of the LSVC was reconstructed using an atrial wall flap created from the anterior wall of the right side atrium. The anterior wall of the LSVC was enlarged using a fresh autologous pericardial patch. The postoperative recovery was uneventful, with no venous congestion. Reconstruction using an atrial wall flap offers an alternative surgical method for treating patients with a common atrium into which the LSVC drains directly into the left side.

Mitral stenosis and regurgitation (MSR) induced by congenital mitral valve dysplasia generally necessitates surgical repair or valve replacement. Here we report the case of a female infant diagnosed with congenital MSR that improved with pharmacotherapy alone and without a mitral valve surgery. The patient was a 22-day-old girl diagnosed with severe MSR accompanied with over-systemic pulmonary hypertension (PH). She was treated with respiratory support using a high-flow nasal cannula; diuretics and digitalis were also administered. Unexpectedly, the patient’s MSR and PH alleviated, and surgery was avoided. Tethering of the mitral valve induced by left ventricular dilation is known to result in secondary mitral regurgitation in adult ischemic heart disease. We speculated that the underlying mechanisms of MSR in this case: were due to elevation of the right ventricular pressure caused by physiological and pathological PH, which is a result of papillary muscle displacement and tethering of the mitral valve. We consider this the reason for the appearance of MSR on admission. Differentiating functional MSR from organic MSR is crucial while making decisions regarding surgery.