Patients often think that foramen ovale is not closed is a congenital heart defect, but in fact, foramen ovale is not closed and congenital heart defect are two different concepts. There are many people who think that foramen ovale insufficiency is also a congenital heart defect, but foramen ovale insufficiency is not usually considered a congenital heart defect. There are distinct differences between the two and they each have different characteristics. One of the more striking differences is that most of the oval foramen insufficiency does not require treatment, while most of the congenital heart disease atrial defect requires treatment. 1, congenital heart disease atrial defect: urgent treatment congenital heart disease atrial defect belongs to a common type of congenital heart disease. Congenital heart disease atrial defect congenital heart disease atrial defect can be divided into two categories: primary orifice defect and secondary orifice defect, with the latter being the most common. Secondary orifice defect is located in the posterior part of the coronary sinus opening, and then there are the following types according to the corresponding anatomical parts: (1) oval orifice type: in the central part of the atrial septum; (2) superior vena cava type: near the entrance of superior vena cava: inferior vena cava type: near the entrance of inferior vena cava. The vast majority are single foramen, a few are multiforaminal, and some are sieve-shaped. The diameter of the defect is usually about 2-4 cm. if it is accompanied by ectopic pulmonary venous drainage into the atrium, it is called partial pulmonary venous ectopic drainage disease. The primary orifice defect, located anteriorly below the coronary sinus orifice, has an inferior border near or for the mitral annulus and is often accompanied by a large mitral valvular cleft, called partial atrioventricular common channel. At about day 28 of embryonic development, the primitive heart chambers begin to separate into four atrioventricular chambers. The process of development is as follows: the middle of the ventral dorsal sides of the primitive heart chambers protrude and thicken inward to form endocardial cushions. The two ventral endocardial cushions gradually approach and fuse with each other at the midline, while the tissue on both sides forms part of the atrioventricular valve, which is the septal valve of the tricuspid valve on the right side and the large mitral valve on the left side. In addition, the lateral cushions also develop into valves that together form the tricuspid and mitral valves that separate the atria from the ventricles. At the same time, the atria and ventricles also have intervals growing from the ends of the midline toward the endocardial cushions, separating the heart chambers into two atria and two ventricles. 2.Unconfined foramen ovale: no surgery is needed The unconfined foramen ovale is a primitive heart that is a longitudinal straight duct with some of the atria and ventricles distinguishable in the 4th week as the embryo develops. If the interatrial septum does not completely adhere to the endocardial cushion during growth at 5 to 6 weeks, an orifice is left in the right and left atria, which is the foramen ovale. Normally, an unclosed foramen ovale is not considered a precordial disease. During fetal life, fetal blood circulation requires the use of the foramen ovale to allow some blood to flow from the right atrium to the left atrium. After the baby is born, as the umbilical vessel is disconnected and the newborn’s own pulmonary circulation is established, the pressure in the left atrium is higher than that in the right atrium, the blood from the right atrium does not flow into the left atrium, and the foramen ovale is functionally closed. After birth, the pressure in the left atrium is higher than that in the right atrium, causing the valves of the foramen ovale to close tightly against the secondary atrial septum. The blood flow between the right and left atria is usually completely cut off by the eighth month of life or longer. However, in 20%-25% of normal individuals, the foramen ovale valve and the septum do not completely fuse, leaving a small potential fissure called an unclosed foramen ovale. This does not usually cause a shunt between the two interatrial compartments and is not hemodynamically significant, therefore surgical treatment is not required. It is very common for newborns to be found with foramen ovale that may not be closed, but most infants with foramen ovale that is not closed are normal physiologically, whereas congenital heart disease atrial defects are only able to close spontaneously when they are as small as 0.3 mm. In addition, congenital atrial defect is not considered as a type of congenital atrial defect, but congenital atrial defect is considered as a type of congenital atrial defect. In conclusion, congenital heart disease atrial defect and foramen ovale non-closure are two different concepts and should not be confused.